style(core): full pyright-based type-checking

Changes many fields to required -- as far as we were able to figure out,
signing would fail if these fields aren't provided anyway, so this
should not pose a compatibility problem.

Co-authored-by: matejcik <ja@matejcik.cz>

common/protob/messages-binance.proto

@@ -5,6 +5,14 @@ package hw.trezor.messages.binance;
 option java_package = "com.satoshilabs.trezor.lib.protobuf";
 option java_outer_classname = "TrezorMessageBinance";
 
+/** XXX
+
+Most likely, ALL fields in this file should be `required`. We are leaving some optionals
+in place, in cases where the field value continues to the JSON as a string -- on the off
+chance that somebody is relying on the behavior.
+
+*/
+
 /**
  * Request: Ask the device for a Binance address.
  * @start
@@ -52,12 +60,12 @@ message BinancePublicKey {
 */
 message BinanceSignTx {
     repeated uint32 address_n = 1; // BIP-32-style path to derive the key from master node
-    optional uint32 msg_count = 2; // count of Binance<Any>Msg to be included in this tx
-    optional sint64 account_number = 3;
+    required uint32 msg_count = 2; // count of Binance<Any>Msg to be included in this tx
+    required sint64 account_number = 3;
     optional string chain_id = 4;
     optional string memo = 5;
-    optional sint64 sequence = 6;
-    optional sint64 source = 7;
+    required sint64 sequence = 6;
+    required sint64 source = 7;
 }
 
 /**
@@ -79,13 +87,13 @@ message BinanceTransferMsg {
     repeated BinanceInputOutput outputs = 2;
 
     message BinanceInputOutput {
-        optional string address = 1;
+        required string address = 1;
         repeated BinanceCoin coins = 2;
     }
 
     message BinanceCoin {
-        optional sint64 amount = 1;
-        optional string denom = 2;
+        required sint64 amount = 1;
+        required string denom = 2;
     }
 }
 
@@ -96,13 +104,13 @@ message BinanceTransferMsg {
  */
 message BinanceOrderMsg {
     optional string id = 1;
-    optional BinanceOrderType ordertype = 2;
-    optional sint64 price = 3;
-    optional sint64 quantity = 4;
+    required BinanceOrderType ordertype = 2;
+    required sint64 price = 3;
+    required sint64 quantity = 4;
     optional string sender = 5;
-    optional BinanceOrderSide side = 6;
+    required BinanceOrderSide side = 6;
     optional string symbol = 7;
-    optional BinanceTimeInForce timeinforce = 8;
+    required BinanceTimeInForce timeinforce = 8;
 
     enum BinanceOrderType {
         OT_UNKNOWN = 0;

common/protob/messages-eos.proto

@@ -33,9 +33,9 @@ message EosPublicKey {
  */
 message EosSignTx {
     repeated uint32 address_n = 1;   // BIP-32 path to derive the key from master node 44'/194'/0'
-    optional bytes chain_id = 2;     // 256-bit long chain id
-    optional EosTxHeader header = 3; // EOS transaction header
-    optional uint32 num_actions = 4; // number of actions
+    required bytes chain_id = 2;     // 256-bit long chain id
+    required EosTxHeader header = 3; // EOS transaction header
+    required uint32 num_actions = 4; // number of actions
 
     /**
      * Structure representing EOS transaction header
@@ -65,7 +65,7 @@ message EosTxActionRequest {
  * @next Failure
  */
 message EosTxActionAck {
-    optional EosActionCommon common = 1;
+    required EosActionCommon common = 1;
     optional EosActionTransfer transfer = 2;
     optional EosActionDelegate delegate = 3;
     optional EosActionUndelegate undelegate = 4;
@@ -85,16 +85,16 @@ message EosTxActionAck {
      * Structure representing asset type
      */
     message EosAsset {
-        optional sint64 amount = 1;
-        optional uint64 symbol = 2; // Lowest 8 bits used for precision.
+        required sint64 amount = 1;
+        required uint64 symbol = 2; // Lowest 8 bits used for precision.
     }
 
     /**
      * Structure representing action permission level
      */
     message EosPermissionLevel {
-        optional uint64 actor = 1;
-        optional uint64 permission = 2;
+        required uint64 actor = 1;
+        required uint64 permission = 2;
     }
 
     /**
@@ -111,23 +111,23 @@ message EosTxActionAck {
      * Structure representing auth account
      */
     message EosAuthorizationAccount {
-        optional EosPermissionLevel account = 1;
-        optional uint32 weight = 2;
+        required EosPermissionLevel account = 1;
+        required uint32 weight = 2;
     }
 
     /**
      * Structure representing auth delays
      */
     message EosAuthorizationWait {
-        optional uint32 wait_sec = 1;
-        optional uint32 weight = 2;
+        required uint32 wait_sec = 1;
+        required uint32 weight = 2;
     }
 
     /**
      * Structure representing authorization settings
      */
     message EosAuthorization {
-        optional uint32 threshold = 1;
+        required uint32 threshold = 1;
         repeated EosAuthorizationKey keys = 2;
         repeated EosAuthorizationAccount accounts = 3;
         repeated EosAuthorizationWait waits = 4;
@@ -137,8 +137,8 @@ message EosTxActionAck {
      * Structure representing the common part of every action
      */
     message EosActionCommon {
-        optional uint64 account = 1; // Contract name
-        optional uint64 name = 2;    // Action name
+        required uint64 account = 1; // Contract name
+        required uint64 name = 2;    // Action name
         repeated EosPermissionLevel authorization = 3;
     }
 
@@ -146,72 +146,72 @@ message EosTxActionAck {
      * Structure representing transfer data structure
      */
     message EosActionTransfer {
-        optional uint64 sender = 1; // Asset sender
-        optional uint64 receiver = 2;
-        optional EosAsset quantity = 3;
-        optional string memo = 4;
+        required uint64 sender = 1; // Asset sender
+        required uint64 receiver = 2;
+        required EosAsset quantity = 3;
+        required string memo = 4;
     }
 
     /**
      * Structure representing delegation data structure
      */
     message EosActionDelegate {
-        optional uint64 sender = 1;
-        optional uint64 receiver = 2;
-        optional EosAsset net_quantity = 3; // Asset format '1.0000 EOS'
-        optional EosAsset cpu_quantity = 4; // Asset format '1.0000 EOS'
-        optional bool transfer = 5;         // Transfer delegated tokens or not.
+        required uint64 sender = 1;
+        required uint64 receiver = 2;
+        required EosAsset net_quantity = 3; // Asset format '1.0000 EOS'
+        required EosAsset cpu_quantity = 4; // Asset format '1.0000 EOS'
+        required bool transfer = 5;         // Transfer delegated tokens or not.
     }
 
     /**
      * Structure representing the removal of delegated resources from `sender`
      */
     message EosActionUndelegate {
-        optional uint64 sender = 1;
-        optional uint64 receiver = 2;
-        optional EosAsset net_quantity = 3; // Asset format '1.0000 EOS'
-        optional EosAsset cpu_quantity = 4; // Asset format '1.0000 EOS'
+        required uint64 sender = 1;
+        required uint64 receiver = 2;
+        required EosAsset net_quantity = 3; // Asset format '1.0000 EOS'
+        required EosAsset cpu_quantity = 4; // Asset format '1.0000 EOS'
     }
 
     /**
      * Structure representing fallback if undelegate wasnt executed automaticaly.
      */
     message EosActionRefund {
-        optional uint64 owner = 1;
+        required uint64 owner = 1;
     }
 
     /**
      * Structure representing buying RAM operation for EOS tokens
      */
     message EosActionBuyRam {
-        optional uint64 payer = 1;
-        optional uint64 receiver = 2;
-        optional EosAsset quantity = 3; // Asset format '1.0000 EOS'
+        required uint64 payer = 1;
+        required uint64 receiver = 2;
+        required EosAsset quantity = 3; // Asset format '1.0000 EOS'
     }
 
     /**
      * Structure representing buying bytes according to RAM market price.
      */
     message EosActionBuyRamBytes {
-        optional uint64 payer = 1;
-        optional uint64 receiver = 2;
-        optional uint32 bytes = 3; // Number of bytes
+        required uint64 payer = 1;
+        required uint64 receiver = 2;
+        required uint32 bytes = 3; // Number of bytes
     }
 
     /**
      * Structure representing sell RAM
      */
     message EosActionSellRam {
-        optional uint64 account = 1;
-        optional uint64 bytes = 2; // Number of bytes
+        required uint64 account = 1;
+        required uint64 bytes = 2; // Number of bytes
     }
 
     /**
      * Structure representing voting. Currently, there could be up to 30 producers.
      */
     message EosActionVoteProducer {
-        optional uint64 voter = 1;     // Voter account
-        optional uint64 proxy = 2;     // Proxy voter account
+        required uint64 voter = 1;     // Voter account
+        required uint64 proxy = 2;     // Proxy voter account
         repeated uint64 producers = 3; // List of producers
     }
 
@@ -219,47 +219,47 @@ message EosTxActionAck {
      * Structure representing update authorization.
      */
     message EosActionUpdateAuth {
-        optional uint64 account = 1;
-        optional uint64 permission = 2;
-        optional uint64 parent = 3;
-        optional EosAuthorization auth = 4;
+        required uint64 account = 1;
+        required uint64 permission = 2;
+        required uint64 parent = 3;
+        required EosAuthorization auth = 4;
     }
 
     /**
      * Structure representing delete authorization.
      */
     message EosActionDeleteAuth {
-        optional uint64 account = 1;
-        optional uint64 permission = 2;
+        required uint64 account = 1;
+        required uint64 permission = 2;
     }
 
     /**
      * Structure representing link authorization to action.
      */
     message EosActionLinkAuth {
-        optional uint64 account = 1;
-        optional uint64 code = 2;
-        optional uint64 type = 3;
-        optional uint64 requirement = 4;
+        required uint64 account = 1;
+        required uint64 code = 2;
+        required uint64 type = 3;
+        required uint64 requirement = 4;
     }
 
     /**
      * Structure representing unlink authorization from action.
      */
     message EosActionUnlinkAuth {
-        optional uint64 account = 1;
-        optional uint64 code = 2;
-        optional uint64 type = 3;
+        required uint64 account = 1;
+        required uint64 code = 2;
+        required uint64 type = 3;
     }
 
     /**
      * Structure representing creation of a new account.
      */
     message EosActionNewAccount {
-        optional uint64 creator = 1;
-        optional uint64 name = 2;
-        optional EosAuthorization owner = 3;
-        optional EosAuthorization active = 4;
+        required uint64 creator = 1;
+        required uint64 name = 2;
+        required EosAuthorization owner = 3;
+        required EosAuthorization active = 4;
     }
 
     /**
@@ -267,7 +267,7 @@ message EosTxActionAck {
      */
     message EosActionUnknown {
         required uint32 data_size = 1;
-        optional bytes data_chunk = 2;
+        required bytes data_chunk = 2;
     }
 }
 

common/protob/messages-nem.proto

@@ -12,9 +12,9 @@ option java_outer_classname = "TrezorMessageNem";
  * @next Failure
  */
 message NEMGetAddress {
-    repeated uint32 address_n = 1;      // BIP-32 path to derive the key from master node
-    optional uint32 network = 2;        // Network ID (0x68 = Mainnet, 0x98 = Testnet, 0x60 = Mijin)
-    optional bool show_display = 3;     // Optionally show on display before sending the result
+    repeated uint32 address_n = 1;              // BIP-32 path to derive the key from master node
+    optional uint32 network = 2 [default=0x68]; // Network ID (0x68 = Mainnet, 0x98 = Testnet, 0x60 = Mijin)
+    optional bool show_display = 3;             // Optionally show on display before sending the result
 }
 
 /**
@@ -32,7 +32,7 @@ message NEMAddress {
  * @next Failure
  */
 message NEMSignTx {
-    optional NEMTransactionCommon transaction = 1;                  // Common part of transaction
+    required NEMTransactionCommon transaction = 1;                  // Common part of transaction
     optional NEMTransactionCommon multisig = 2;                     // Common part of inner transaction for multisig transactions
     optional NEMTransfer transfer = 3;                              // Transfer transaction part
     optional bool cosigning = 4;                                    // Whether cosigning or initiating the multisig transaction
@@ -45,55 +45,55 @@ message NEMSignTx {
     * Structure representing the common part for NEM transactions
     */
     message NEMTransactionCommon {
-        repeated uint32 address_n = 1;  // BIP-32 path to derive the key from master node
-        optional uint32 network = 2;    // Network ID (0x68 = Mainnet, 0x98 = Testnet, 0x60 = Mijin)
-        optional uint32 timestamp = 3;  // Number of seconds elapsed since the creation of the nemesis block
-        optional uint64 fee = 4;        // Fee for the transaction
-        optional uint32 deadline = 5;   // Deadline of the transaction
-        optional bytes signer = 6;      // Public key of the account (for multisig transactions)
+        repeated uint32 address_n = 1;              // BIP-32 path to derive the key from master node
+        optional uint32 network = 2 [default=0x68]; // Network ID (0x68 = Mainnet, 0x98 = Testnet, 0x60 = Mijin)
+        required uint32 timestamp = 3;              // Number of seconds elapsed since the creation of the nemesis block
+        required uint64 fee = 4;                    // Fee for the transaction
+        required uint32 deadline = 5;               // Deadline of the transaction
+        optional bytes signer = 6;                  // Public key of the account (for multisig transactions)
     }
     /**
     * Structure representing the transfer transaction part for NEM transactions
     */
     message NEMTransfer {
-        optional string recipient = 1;      // Address of the recipient
-        optional uint64 amount = 2;         // Amount of micro NEM that is transferred
-        optional bytes payload = 3;         // Actual message data (unencrypted)
-        optional bytes public_key = 4;      // Public key of the recipient (for encrypted payloads)
-        repeated NEMMosaic mosaics = 5;     // Attached mosaics
+        required string recipient = 1;              // Address of the recipient
+        required uint64 amount = 2;                 // Amount of micro NEM that is transferred
+        optional bytes payload = 3 [default=""];    // Actual message data (unencrypted)
+        optional bytes public_key = 4;              // Public key of the recipient (for encrypted payloads)
+        repeated NEMMosaic mosaics = 5;             // Attached mosaics
         /**
         * Structure representing the mosaic attachment for NEM transfer transactions
         */
         message NEMMosaic {
-            optional string namespace = 1;  // Fully qualified name of the namespace
-            optional string mosaic = 2;     // Name of the mosaic definition
-            optional uint64 quantity = 3;   // Mosaic quantity, always given in smallest units
+            required string namespace = 1;  // Fully qualified name of the namespace
+            required string mosaic = 2;     // Name of the mosaic definition
+            required uint64 quantity = 3;   // Mosaic quantity, always given in smallest units
         }
     }
     /**
     * Structure representing the provision namespace part for NEM transactions
     */
     message NEMProvisionNamespace {
-        optional string namespace = 1;  // New part concatenated to the parent
+        required string namespace = 1;  // New part concatenated to the parent
         optional string parent = 2;     // Parent namespace (for child namespaces)
-        optional string sink = 3;       // Rental fee sink address
-        optional uint64 fee = 4;        // Rental fee
+        required string sink = 3;       // Rental fee sink address
+        required uint64 fee = 4;        // Rental fee
     }
     /**
     * Structure representing the mosaic definition creation part for NEM transactions
     */
     message NEMMosaicCreation {
-        optional NEMMosaicDefinition definition = 1;    // Mosaic definition
-        optional string sink = 2;                       // Creation fee sink address
-        optional uint64 fee = 3;                        // Creation fee
+        required NEMMosaicDefinition definition = 1;    // Mosaic definition
+        required string sink = 2;                       // Creation fee sink address
+        required uint64 fee = 3;                        // Creation fee
         /**
         * Structure representing a mosaic definition
         */
         message NEMMosaicDefinition {
             optional string name = 1;               // User-friendly name of the mosaic (for whitelisted mosaics)
             optional string ticker = 2;             // Ticker of the mosaic (for whitelisted mosaics)
-            optional string namespace = 3;          // Fully qualified name of the namespace
-            optional string mosaic = 4;             // Name of the mosaic definition
+            required string namespace = 3;          // Fully qualified name of the namespace
+            required string mosaic = 4;             // Name of the mosaic definition
             optional uint32 divisibility = 5;       // Number of decimal places that a mosaic can be divided into
             optional NEMMosaicLevy levy = 6;        // Levy type
             optional uint64 fee = 7;                // Levy fee (interpretation depends on levy type)
@@ -103,7 +103,7 @@ message NEMSignTx {
             optional uint64 supply = 11;            // Initial supply to create, always given in entire units
             optional bool mutable_supply = 12;      // Mutable supply
             optional bool transferable = 13;        // Mosaic allows transfers among accounts other than the creator
-            optional string description = 14;       // Mosaic description
+            required string description = 14;       // Mosaic description
             repeated uint32 networks = 15;          // Networks that the mosaic is valid on (for whitelisted mosaics)
             /**
             * Type of levy which will be used for mosaic
@@ -118,10 +118,10 @@ message NEMSignTx {
     * Structure representing the mosaic supply change part for NEM transactions
     */
     message NEMMosaicSupplyChange {
-        optional string namespace = 1;          // Fully qualified name of the namespace
-        optional string mosaic = 2;             // Name of the mosaic definition
-        optional NEMSupplyChangeType type = 3;  // Type of supply change
-        optional uint64 delta = 4;              // Supply delta
+        required string namespace = 1;          // Fully qualified name of the namespace
+        required string mosaic = 2;             // Name of the mosaic definition
+        required NEMSupplyChangeType type = 3;  // Type of supply change
+        required uint64 delta = 4;              // Supply delta
         /**
         * Type of supply change which will be applied to mosaic
         */
@@ -140,8 +140,8 @@ message NEMSignTx {
         * Structure representing the cosignatory modification for aggregate modification transactions
         */
         message NEMCosignatoryModification {
-            optional NEMModificationType type = 1;  // Type of cosignatory modification
-            optional bytes public_key = 2;          // Public key of the cosignatory
+            required NEMModificationType type = 1;  // Type of cosignatory modification
+            required bytes public_key = 2;          // Public key of the cosignatory
             /**
             * Type of cosignatory modification
             */
@@ -155,8 +155,8 @@ message NEMSignTx {
     * Structure representing the importance transfer part for NEM transactions
     */
     message NEMImportanceTransfer {
-        optional NEMImportanceTransferMode mode = 1;    // Mode of importance transfer
-        optional bytes public_key = 2;                  // Public key of the remote account
+        required NEMImportanceTransferMode mode = 1;    // Mode of importance transfer
+        required bytes public_key = 2;                  // Public key of the remote account
         /**
         * Mode of importance transfer
         */

common/protob/messages-ripple.proto

@@ -30,11 +30,11 @@ message RippleAddress {
  */
 message RippleSignTx {
     repeated uint32 address_n = 1;              // BIP-32 path. For compatibility with other wallets, must be m/44'/144'/index'
-    optional uint64 fee = 2;                    // fee (in drops) for the transaction
-    optional uint32 flags = 3;                  // transaction flags
-    optional uint32 sequence = 4;               // transaction sequence number
+    required uint64 fee = 2;                    // fee (in drops) for the transaction
+    optional uint32 flags = 3 [default=0];      // transaction flags
+    required uint32 sequence = 4;               // transaction sequence number
     optional uint32 last_ledger_sequence = 5;   // see https://developers.ripple.com/reliable-transaction-submission.html#lastledgersequence
-    optional RipplePayment payment = 6;         // Payment transaction type
+    required RipplePayment payment = 6;         // Payment transaction type
 
     /**
      * Payment transaction type

common/protob/messages-tezos.proto

@@ -102,8 +102,8 @@ message TezosSignTx {
             optional TezosManagerTransfer transfer = 3;
 
             message TezosManagerTransfer {
-                optional TezosContractID destination = 1;
-                optional uint64 amount = 2;
+                required TezosContractID destination = 1;
+                required uint64 amount = 2;
             }
         }
     }
@@ -138,18 +138,18 @@ message TezosSignTx {
      * Structure representing information for proposal
      */
     message TezosProposalOp {
-        optional bytes source = 1;                  //Contains only public_key_hash, not to be confused with TezosContractID
-        optional uint64 period = 2;
+        required bytes source = 1;                  //Contains only public_key_hash, not to be confused with TezosContractID
+        required uint64 period = 2;
         repeated bytes proposals = 4;
     }
     /**
      * Structure representing information for ballot
      */
     message TezosBallotOp {
-        optional bytes source = 1;                  //Contains only public_key_hash, not to be confused with TezosContractID
-        optional uint64 period = 2;
-        optional bytes proposal = 3;
-        optional TezosBallotType ballot = 4;
+        required bytes source = 1;                  //Contains only public_key_hash, not to be confused with TezosContractID
+        required uint64 period = 2;
+        required bytes proposal = 3;
+        required TezosBallotType ballot = 4;
 
         enum TezosBallotType {
             Yay = 0;

core/.gitignore

@@ -7,3 +7,4 @@ tests/trezor_monero_tests*
 .coverage
 .coverage.*
 htmlcov/
+mypy_report

core/Makefile

@@ -110,14 +110,19 @@ pylint: ## run pylint on application sources and tests
 mypy:
 	mypy --config-file ../setup.cfg \
 		src/main.py \
-		src/apps/bitcoin \
-		src/apps/cardano \
-		src/apps/ethereum \
-		src/apps/management \
-		src/apps/misc \
-		src/apps/stellar \
-		src/apps/webauthn \
-		src/trezor/ui
+		src/apps \
+		src/trezor \
+		src/storage \
+		--exclude src/apps/monero
+
+mypy_report:
+	mypy --config-file ../setup.cfg \
+		src/main.py \
+		src/apps \
+		src/trezor \
+		src/storage \
+		--exclude src/apps/monero \
+		--html-report mypy_report
 
 clippy:
 	cd embed/rust ; cargo clippy

core/embed/extmod/rustmods/modtrezorproto.c

@@ -26,12 +26,12 @@
 /// from trezor.protobuf import MessageType
 /// T = TypeVar("T", bound=MessageType)
 
-/// def type_for_name(name: str) -> Type[MessageType]:
+/// def type_for_name(name: str) -> type[T]:
 ///     """Find the message definition for the given protobuf name."""
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorutils_protobuf_type_for_name_obj,
                                  protobuf_type_for_name);
 
-/// def type_for_wire(wire_type: int) -> Type[MessageType]:
+/// def type_for_wire(wire_type: int) -> type[T]:
 ///     """Find the message definition for the given wire type (numeric
 ///     identifier)."""
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorutils_protobuf_type_for_wire_obj,

core/mocks/generated/trezorproto.pyi

@@ -4,12 +4,12 @@ T = TypeVar("T", bound=MessageType)
 
 
 # extmod/rustmods/modtrezorproto.c
-def type_for_name(name: str) -> Type[MessageType]:
+def type_for_name(name: str) -> type[T]:
     """Find the message definition for the given protobuf name."""
 
 
 # extmod/rustmods/modtrezorproto.c
-def type_for_wire(wire_type: int) -> Type[MessageType]:
+def type_for_wire(wire_type: int) -> type[T]:
     """Find the message definition for the given wire type (numeric
     identifier)."""
 

core/mocks/uctypes.pyi

@@ -24,7 +24,9 @@ FLOAT32: int
 class struct:
     def __init__(self, addr: int, descriptor: dict, layout_type: int = ...) -> None: ...
 
-def sizeof(struct: struct) -> int: ...
+StructDict = dict[str, int | tuple[int, int]]
+
+def sizeof(struct: struct | bytearray | StructDict, endianity: int = LITTLE_ENDIAN, /) -> int: ...
 def addressof(obj: bytes) -> int: ...
 def bytes_at(addr: int, size: int) -> bytes: ...
 def bytearray_at(addr: int, size: int) -> bytearray: ...

core/pyrightconfig.json

@@ -0,0 +1,14 @@
+{
+    "include": [
+        "src"
+    ],
+    "exclude": [
+        "src/apps/monero",
+        "src/typing.py",
+        "src/all_modules.py"
+    ],
+    "stubPath": "mocks/generated",
+    "typeCheckingMode": "basic",
+    "pythonVersion": "3.10",
+    "reportMissingModuleSource": false
+}

core/src/all_modules.py

@@ -38,6 +38,8 @@ main
 import main
 session
 import session
+typing
+import typing
 usb
 import usb
 storage

core/src/apps/base.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 import storage.cache
 import storage.device
 from trezor import config, utils, wire, workflow
@@ -6,9 +8,8 @@ from trezor.messages import Success
 
 from . import workflow_handlers
 
-if False:
+if TYPE_CHECKING:
     from trezor import protobuf
-    from typing import NoReturn
     from trezor.messages import (
         Features,
         Initialize,
@@ -25,6 +26,7 @@ if False:
 def get_features() -> Features:
     import storage.recovery
     import storage.sd_salt
+    import storage  # workaround for https://github.com/microsoft/pyright/issues/2685
 
     from trezor import sdcard
     from trezor.enums import Capability
@@ -130,7 +132,7 @@ async def handle_GetFeatures(ctx: wire.Context, msg: GetFeatures) -> Features:
     return get_features()
 
 
-async def handle_Cancel(ctx: wire.Context, msg: Cancel) -> NoReturn:
+async def handle_Cancel(ctx: wire.Context, msg: Cancel) -> Success:
     raise wire.ActionCancelled
 
 
@@ -262,8 +264,6 @@ def get_pinlocked_handler(
         return orig_handler
 
     async def wrapper(ctx: wire.Context, msg: wire.Msg) -> protobuf.MessageType:
-        # mypy limitation: orig_handler is not recognized as non-None
-        assert orig_handler is not None
         await unlock_device(ctx)
         return await orig_handler(ctx, msg)
 

core/src/apps/binance/get_address.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor.messages import BinanceAddress, BinanceGetAddress
 from trezor.ui.layouts import show_address
 
@@ -6,9 +8,14 @@ from apps.common.keychain import Keychain, auto_keychain
 
 from .helpers import address_from_public_key
 
+if TYPE_CHECKING:
+    from trezor.wire import Context
+
 
 @auto_keychain(__name__)
-async def get_address(ctx, msg: BinanceGetAddress, keychain: Keychain):
+async def get_address(
+    ctx: Context, msg: BinanceGetAddress, keychain: Keychain
+) -> BinanceAddress:
     HRP = "bnb"
 
     await paths.validate_path(ctx, keychain, msg.address_n)

core/src/apps/binance/get_public_key.py

@@ -1,3 +1,4 @@
+from typing import TYPE_CHECKING
 from ubinascii import hexlify
 
 from trezor.messages import BinanceGetPublicKey, BinancePublicKey
@@ -6,9 +7,14 @@ from trezor.ui.layouts import show_pubkey
 from apps.common import paths
 from apps.common.keychain import Keychain, auto_keychain
 
+if TYPE_CHECKING:
+    from trezor.wire import Context
+
 
 @auto_keychain(__name__)
-async def get_public_key(ctx, msg: BinanceGetPublicKey, keychain: Keychain):
+async def get_public_key(
+    ctx: Context, msg: BinanceGetPublicKey, keychain: Keychain
+) -> BinancePublicKey:
     await paths.validate_path(ctx, keychain, msg.address_n)
     node = keychain.derive(msg.address_n)
     pubkey = node.public_key()

core/src/apps/binance/helpers.py

@@ -1,5 +1,7 @@
 from micropython import const
+from typing import TYPE_CHECKING
 
+from trezor import wire
 from trezor.crypto import bech32
 from trezor.crypto.scripts import sha256_ripemd160
 from trezor.messages import (
@@ -10,6 +12,9 @@ from trezor.messages import (
     BinanceTransferMsg,
 )
 
+if TYPE_CHECKING:
+    from trezor.protobuf import MessageType
+
 ENVELOPE_BLUEPRINT = '{{"account_number":"{account_number}","chain_id":"{chain_id}","data":null,"memo":"{memo}","msgs":[{msgs}],"sequence":"{sequence}","source":"{source}"}}'
 MSG_TRANSFER_BLUEPRINT = '{{"inputs":[{inputs}],"outputs":[{outputs}]}}'
 MSG_NEWORDER_BLUEPRINT = '{{"id":"{id}","ordertype":{ordertype},"price":{price},"quantity":{quantity},"sender":"{sender}","side":{side},"symbol":"{symbol}","timeinforce":{timeinforce}}}'
@@ -21,7 +26,7 @@ COIN_BLUEPRINT = '{{"amount":{amount},"denom":"{denom}"}}'
 DECIMALS = const(8)
 
 
-def produce_json_for_signing(envelope: BinanceSignTx, msg) -> str:
+def produce_json_for_signing(envelope: BinanceSignTx, msg: MessageType) -> str:
     if BinanceTransferMsg.is_type_of(msg):
         json_msg = produce_transfer_json(msg)
     elif BinanceOrderMsg.is_type_of(msg):
@@ -29,12 +34,10 @@ def produce_json_for_signing(envelope: BinanceSignTx, msg) -> str:
     elif BinanceCancelMsg.is_type_of(msg):
         json_msg = produce_cancel_json(msg)
     else:
-        raise ValueError("input message unrecognized, is of type " + type(msg).__name__)
-
-    if envelope.source is None or envelope.source < 0:
-        raise ValueError("source missing or invalid")
+        raise wire.ProcessError("input message unrecognized")
 
-    source = envelope.source
+    if envelope.source < 0:
+        raise wire.DataError("Source is invalid")
 
     return ENVELOPE_BLUEPRINT.format(
         account_number=envelope.account_number,
@@ -42,12 +45,12 @@ def produce_json_for_signing(envelope: BinanceSignTx, msg) -> str:
         memo=envelope.memo,
         msgs=json_msg,
         sequence=envelope.sequence,
-        source=source,
+        source=envelope.source,
     )
 
 
 def produce_transfer_json(msg: BinanceTransferMsg) -> str:
-    def make_input_output(input_output: BinanceInputOutput):
+    def make_input_output(input_output: BinanceInputOutput) -> str:
         coins = ",".join(
             COIN_BLUEPRINT.format(amount=c.amount, denom=c.denom)
             for c in input_output.coins
@@ -89,5 +92,6 @@ def address_from_public_key(pubkey: bytes, hrp: str) -> str:
     h = sha256_ripemd160(pubkey).digest()
 
     convertedbits = bech32.convertbits(h, 8, 5, False)
+    assert convertedbits is not None
 
     return bech32.bech32_encode(hrp, convertedbits, bech32.Encoding.BECH32)

core/src/apps/binance/layout.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor.enums import BinanceOrderSide, ButtonRequestType
 from trezor.messages import (
     BinanceCancelMsg,
@@ -11,11 +13,14 @@ from trezor.ui.layouts.tt.altcoin import confirm_transfer_binance
 
 from . import helpers
 
+if TYPE_CHECKING:
+    from trezor.wire import Context
+
 
-async def require_confirm_transfer(ctx, msg: BinanceTransferMsg):
+async def require_confirm_transfer(ctx: Context, msg: BinanceTransferMsg) -> None:
     items = []
 
-    def make_input_output_pages(msg: BinanceInputOutput, direction):
+    def make_input_output_pages(msg: BinanceInputOutput, direction: str) -> None:
         for coin in msg.coins:
             items.append(
                 (
@@ -34,36 +39,36 @@ async def require_confirm_transfer(ctx, msg: BinanceTransferMsg):
     await confirm_transfer_binance(ctx, items)
 
 
-async def require_confirm_cancel(ctx, msg: BinanceCancelMsg):
+async def require_confirm_cancel(ctx: Context, msg: BinanceCancelMsg) -> None:
     await confirm_properties(
         ctx,
         "confirm_cancel",
         title="Confirm cancel",
         props=[
-            ("Sender address:", msg.sender),
-            ("Pair:", msg.symbol),
-            ("Order ID:", msg.refid),
+            ("Sender address:", str(msg.sender)),
+            ("Pair:", str(msg.symbol)),
+            ("Order ID:", str(msg.refid)),
         ],
         hold=True,
         br_code=ButtonRequestType.SignTx,
     )
 
 
-async def require_confirm_order(ctx, msg: BinanceOrderMsg):
+async def require_confirm_order(ctx: Context, msg: BinanceOrderMsg) -> None:
     if msg.side == BinanceOrderSide.BUY:
         side = "Buy"
     elif msg.side == BinanceOrderSide.SELL:
         side = "Sell"
     else:
-        side = "?"
+        side = "Unknown"
 
     await confirm_properties(
         ctx,
         "confirm_order",
         title="Confirm order",
         props=[
-            ("Sender address:", msg.sender),
-            ("Pair:", msg.symbol),
+            ("Sender address:", str(msg.sender)),
+            ("Pair:", str(msg.symbol)),
             ("Side:", side),
             ("Quantity:", format_amount(msg.quantity, helpers.DECIMALS)),
             ("Price:", format_amount(msg.price, helpers.DECIMALS)),

core/src/apps/binance/sign_tx.py

@@ -6,6 +6,7 @@ from trezor.messages import (
     BinanceCancelMsg,
     BinanceOrderMsg,
     BinanceSignedTx,
+    BinanceSignTx,
     BinanceTransferMsg,
     BinanceTxRequest,
 )
@@ -17,7 +18,9 @@ from . import helpers, layout
 
 
 @auto_keychain(__name__)
-async def sign_tx(ctx, envelope, keychain: Keychain):
+async def sign_tx(
+    ctx: wire.Context, envelope: BinanceSignTx, keychain: Keychain
+) -> BinanceSignedTx:
     # create transaction message -> sign it -> create signature/pubkey message -> serialize all
     if envelope.msg_count > 1:
         raise wire.DataError("Multiple messages not supported.")
@@ -34,8 +37,8 @@ async def sign_tx(ctx, envelope, keychain: Keychain):
         MessageType.BinanceTransferMsg,
     )
 
-    if envelope.source is None or envelope.source < 0:
-        raise wire.DataError("Source missing or invalid.")
+    if envelope.source < 0:
+        raise wire.DataError("Source is invalid.")
 
     msg_json = helpers.produce_json_for_signing(envelope, msg)
 
@@ -46,7 +49,7 @@ async def sign_tx(ctx, envelope, keychain: Keychain):
     elif BinanceCancelMsg.is_type_of(msg):
         await layout.require_confirm_cancel(ctx, msg)
     else:
-        raise ValueError("input message unrecognized, is of type " + type(msg).__name__)
+        raise wire.ProcessError("input message unrecognized")
 
     signature_bytes = generate_content_signature(msg_json.encode(), node.private_key())
 

core/src/apps/bitcoin/addresses.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import wire
 from trezor.crypto import base58, cashaddr
 from trezor.crypto.curve import bip340
@@ -13,7 +15,7 @@ from .common import ecdsa_hash_pubkey, encode_bech32_address
 from .multisig import multisig_get_pubkeys, multisig_pubkey_index
 from .scripts import output_script_native_segwit, write_output_script_multisig
 
-if False:
+if TYPE_CHECKING:
     from trezor.crypto import bip32
 
 

core/src/apps/bitcoin/authorization.py

@@ -1,4 +1,5 @@
 from micropython import const
+from typing import TYPE_CHECKING
 
 from trezor import wire
 from trezor.messages import AuthorizeCoinJoin
@@ -7,7 +8,7 @@ from apps.common import authorization
 
 from .common import BIP32_WALLET_DEPTH
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import (
         GetOwnershipProof,
         SignTx,

core/src/apps/bitcoin/authorize_coinjoin.py

@@ -1,4 +1,5 @@
 from micropython import const
+from typing import TYPE_CHECKING
 
 from trezor import ui
 from trezor.messages import AuthorizeCoinJoin, Success
@@ -13,7 +14,7 @@ from .common import BIP32_WALLET_DEPTH
 from .keychain import validate_path_against_script_type, with_keychain
 from .sign_tx.layout import format_coin_amount
 
-if False:
+if TYPE_CHECKING:
     from trezor import wire
     from apps.common.coininfo import CoinInfo
     from apps.common.keychain import Keychain

core/src/apps/bitcoin/common.py

@@ -1,4 +1,5 @@
 from micropython import const
+from typing import TYPE_CHECKING
 
 from trezor import wire
 from trezor.crypto import bech32, bip32, der
@@ -7,9 +8,9 @@ from trezor.crypto.hashlib import sha256
 from trezor.enums import InputScriptType, OutputScriptType
 from trezor.utils import HashWriter, ensure
 
-if False:
-    from enum import IntEnum
+if TYPE_CHECKING:
     from typing import Tuple
+    from enum import IntEnum
     from apps.common.coininfo import CoinInfo
     from trezor.messages import TxInput
 else:
@@ -131,6 +132,7 @@ def decode_bech32_address(prefix: str, address: str) -> Tuple[int, bytes]:
     witver, raw = bech32.decode(prefix, address)
     if witver not in _BECH32_WITVERS:
         raise wire.ProcessError("Invalid address witness program")
+    assert witver is not None
     assert raw is not None
     return witver, bytes(raw)
 

core/src/apps/bitcoin/get_address.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor.crypto import bip32
 from trezor.enums import InputScriptType
 from trezor.messages import Address
@@ -9,7 +11,7 @@ from . import addresses
 from .keychain import validate_path_against_script_type, with_keychain
 from .multisig import multisig_pubkey_index
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import GetAddress
     from trezor.messages import HDNodeType
     from trezor import wire
@@ -62,8 +64,8 @@ async def get_address(
     else:
         address_qr = address  # base58 address
 
+    multisig_xpub_magic = coin.xpub_magic
     if msg.multisig:
-        multisig_xpub_magic = coin.xpub_magic
         if coin.segwit and not msg.ignore_xpub_magic:
             if (
                 msg.script_type == InputScriptType.SPENDWITNESS

core/src/apps/bitcoin/get_ownership_id.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import wire
 from trezor.enums import InputScriptType
 from trezor.messages import GetOwnershipId, OwnershipId
@@ -8,7 +10,7 @@ from . import addresses, common, scripts
 from .keychain import validate_path_against_script_type, with_keychain
 from .ownership import get_identifier
 
-if False:
+if TYPE_CHECKING:
     from apps.common.coininfo import CoinInfo
     from apps.common.keychain import Keychain
 

core/src/apps/bitcoin/get_ownership_proof.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import ui, wire
 from trezor.enums import InputScriptType
 from trezor.messages import GetOwnershipProof, OwnershipProof
@@ -9,7 +11,7 @@ from . import addresses, common, scripts
 from .keychain import validate_path_against_script_type, with_keychain
 from .ownership import generate_proof, get_identifier
 
-if False:
+if TYPE_CHECKING:
     from apps.common.coininfo import CoinInfo
     from apps.common.keychain import Keychain
     from .authorization import CoinJoinAuthorization

core/src/apps/bitcoin/get_public_key.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import wire
 from trezor.enums import InputScriptType
 from trezor.messages import HDNodeType, PublicKey
@@ -5,7 +7,7 @@ from trezor.messages import HDNodeType, PublicKey
 from apps.common import coininfo, paths
 from apps.common.keychain import get_keychain
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import GetPublicKey
 
 
@@ -34,18 +36,18 @@ async def get_public_key(ctx: wire.Context, msg: GetPublicKey) -> PublicKey:
         and script_type == InputScriptType.SPENDP2SHWITNESS
         and (msg.ignore_xpub_magic or coin.xpub_magic_segwit_p2sh is not None)
     ):
-        # TODO: resolve type: ignore below
+        assert coin.xpub_magic_segwit_p2sh is not None
         node_xpub = node.serialize_public(
-            coin.xpub_magic if msg.ignore_xpub_magic else coin.xpub_magic_segwit_p2sh  # type: ignore
+            coin.xpub_magic if msg.ignore_xpub_magic else coin.xpub_magic_segwit_p2sh
         )
     elif (
         coin.segwit
         and script_type == InputScriptType.SPENDWITNESS
         and (msg.ignore_xpub_magic or coin.xpub_magic_segwit_native is not None)
     ):
-        # TODO: resolve type: ignore below
+        assert coin.xpub_magic_segwit_native is not None
         node_xpub = node.serialize_public(
-            coin.xpub_magic if msg.ignore_xpub_magic else coin.xpub_magic_segwit_native  # type: ignore
+            coin.xpub_magic if msg.ignore_xpub_magic else coin.xpub_magic_segwit_native
         )
     else:
         raise wire.DataError("Invalid combination of coin and script_type")

core/src/apps/bitcoin/keychain.py

@@ -1,5 +1,6 @@
 import gc
 from micropython import const
+from typing import TYPE_CHECKING
 
 from trezor import wire
 from trezor.enums import InputScriptType
@@ -11,27 +12,44 @@ from apps.common.paths import PATTERN_BIP44, PathSchema
 from . import authorization
 from .common import BITCOIN_NAMES
 
-if False:
-    from typing import Awaitable, Callable, Iterable, TypeVar
+if TYPE_CHECKING:
+    from typing import Awaitable, Callable, Iterable, TypeVar, Union
     from typing_extensions import Protocol
 
     from trezor.protobuf import MessageType
 
+    from trezor.messages import (
+        AuthorizeCoinJoin,
+        GetAddress,
+        GetOwnershipId,
+        GetOwnershipProof,
+        GetPublicKey,
+        SignMessage,
+        SignTx,
+        VerifyMessage,
+    )
+
     from apps.common.keychain import Keychain, MsgOut, Handler
     from apps.common.paths import Bip32Path
 
-    class MsgWithCoinName(Protocol):
-        coin_name: str
+    BitcoinMessage = Union[
+        AuthorizeCoinJoin,
+        GetAddress,
+        GetOwnershipId,
+        GetOwnershipProof,
+        GetPublicKey,
+        SignMessage,
+        SignTx,
+        VerifyMessage,
+    ]
 
     class MsgWithAddressScriptType(Protocol):
-        # XXX should be Bip32Path but that fails
-        address_n: list[int] = ...
-        script_type: InputScriptType = ...
+        address_n: Bip32Path
+        script_type: InputScriptType
 
-    MsgIn = TypeVar("MsgIn", bound=MsgWithCoinName)
+    MsgIn = TypeVar("MsgIn", bound=BitcoinMessage)
     HandlerWithCoinInfo = Callable[..., Awaitable[MsgOut]]
 
-
 # BIP-45 for multisig: https://github.com/bitcoin/bips/blob/master/bip-0045.mediawiki
 PATTERN_BIP45 = "m/45'/[0-100]/change/address_index"
 

core/src/apps/bitcoin/ownership.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import utils, wire
 from trezor.crypto import bip32, hashlib, hmac
 from trezor.enums import InputScriptType
@@ -10,7 +12,7 @@ from . import common
 from .scripts import read_bip322_signature_proof, write_bip322_signature_proof
 from .verification import SignatureVerifier
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import MultisigRedeemScriptType
     from apps.common.coininfo import CoinInfo
 

core/src/apps/bitcoin/scripts.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import utils, wire
 from trezor.crypto import base58, cashaddr
 from trezor.crypto.hashlib import sha256
@@ -23,7 +25,7 @@ from .writers import (
     write_op_push,
 )
 
-if False:
+if TYPE_CHECKING:
     from typing import Sequence
 
     from trezor.messages import MultisigRedeemScriptType, TxInput
@@ -172,7 +174,7 @@ def parse_input_script_p2pkh(
         if len(pubkey) != n:
             raise ValueError
     except (ValueError, EOFError):
-        wire.DataError("Invalid scriptSig.")
+        raise wire.DataError("Invalid scriptSig.")
 
     return pubkey, signature, sighash_type
 

core/src/apps/bitcoin/scripts_decred.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import utils, wire
 from trezor.crypto import base58
 from trezor.crypto.base58 import blake256d_32
@@ -15,7 +17,7 @@ from .scripts import (  # noqa: F401
 )
 from .writers import op_push_length, write_bitcoin_varint, write_op_push
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import MultisigRedeemScriptType
 
     from apps.common.coininfo import CoinInfo

core/src/apps/bitcoin/sign_message.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import wire
 from trezor.crypto.curve import secp256k1
 from trezor.enums import InputScriptType
@@ -10,7 +12,7 @@ from apps.common.signverify import decode_message, message_digest
 from .addresses import address_short, get_address
 from .keychain import validate_path_against_script_type, with_keychain
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import SignMessage
 
     from apps.common.coininfo import CoinInfo

core/src/apps/bitcoin/sign_tx/__init__.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import utils, wire
 from trezor.enums import RequestType
 from trezor.messages import TxRequest
@@ -9,7 +11,7 @@ from . import approvers, bitcoin, helpers, progress
 if not utils.BITCOIN_ONLY:
     from . import bitcoinlike, decred, zcash
 
-if False:
+if TYPE_CHECKING:
     from typing import Protocol, Union
 
     from trezor.messages import (

core/src/apps/bitcoin/sign_tx/approvers.py

@@ -1,4 +1,5 @@
 from micropython import const
+from typing import TYPE_CHECKING
 
 from trezor import wire
 from trezor.enums import OutputScriptType
@@ -10,7 +11,7 @@ from ..keychain import validate_path_against_script_type
 from . import helpers, tx_weight
 from .tx_info import OriginalTxInfo, TxInfo
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import SignTx
     from trezor.messages import TxInput
     from trezor.messages import TxOutput

core/src/apps/bitcoin/sign_tx/bitcoin.py

@@ -1,4 +1,5 @@
 from micropython import const
+from typing import TYPE_CHECKING
 
 from trezor import wire
 from trezor.crypto.hashlib import sha256
@@ -22,7 +23,7 @@ from . import approvers, helpers, progress
 from .sig_hasher import BitcoinSigHasher
 from .tx_info import OriginalTxInfo, TxInfo
 
-if False:
+if TYPE_CHECKING:
     from typing import Sequence
 
     from trezor.crypto import bip32
@@ -611,6 +612,8 @@ class Bitcoin:
         self.write_tx_header(h_sign, tx_info.tx, witness_marker=False)
         write_bitcoin_varint(h_sign, tx_info.tx.inputs_count)
 
+        txi_sign = None
+        node = None
         for i in range(tx_info.tx.inputs_count):
             # STAGE_REQUEST_4_INPUT in legacy
             txi = await helpers.request_tx_input(self.tx_req, i, self.coin, tx_hash)
@@ -618,7 +621,6 @@ class Bitcoin:
             # Only the previous UTXO's scriptPubKey is included in h_sign.
             if i == index:
                 txi_sign = txi
-                node = None
                 if not script_pubkey:
                     self.tx_info.check_input(txi)
                     node = self.keychain.derive(txi.address_n)
@@ -643,6 +645,9 @@ class Bitcoin:
             else:
                 self.write_tx_input(h_sign, txi, bytes())
 
+        if txi_sign is None:
+            raise RuntimeError  # index >= tx_info.tx.inputs_count
+
         write_bitcoin_varint(h_sign, tx_info.tx.outputs_count)
 
         for i in range(tx_info.tx.outputs_count):
@@ -712,6 +717,7 @@ class Bitcoin:
 
         write_bitcoin_varint(txh, tx.outputs_count)
 
+        script_pubkey: bytes | None = None
         for i in range(tx.outputs_count):
             # STAGE_REQUEST_3_PREV_OUTPUT in legacy
             txo_bin = await helpers.request_tx_prev_output(
@@ -723,6 +729,8 @@ class Bitcoin:
                 script_pubkey = txo_bin.script_pubkey
                 self.check_prevtx_output(txo_bin)
 
+        assert script_pubkey is not None  # prev_index < tx.outputs_count
+
         await self.write_prev_tx_footer(txh, tx, prev_hash)
 
         if (

core/src/apps/bitcoin/sign_tx/bitcoinlike.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import wire
 from trezor.messages import PrevTx, SignTx, TxInput
 
@@ -8,7 +10,7 @@ from ..common import NONSEGWIT_INPUT_SCRIPT_TYPES, SigHashType
 from . import helpers
 from .bitcoin import Bitcoin
 
-if False:
+if TYPE_CHECKING:
     from typing import Sequence
     from .tx_info import OriginalTxInfo, TxInfo
 

core/src/apps/bitcoin/sign_tx/decred.py

@@ -1,4 +1,5 @@
 from micropython import const
+from typing import TYPE_CHECKING
 
 from trezor import wire
 from trezor.crypto.hashlib import blake256
@@ -22,7 +23,7 @@ OUTPUT_SCRIPT_NULL_SSTXCHANGE = (
     b"\xBD\x76\xA9\x14\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\x88\xAC"
 )
 
-if False:
+if TYPE_CHECKING:
     from typing import Sequence
 
     from trezor.messages import (

core/src/apps/bitcoin/sign_tx/helpers.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import utils, wire
 from trezor.enums import InputScriptType, OutputScriptType, RequestType
 from trezor.messages import (
@@ -23,7 +25,7 @@ from .. import common
 from ..writers import TX_HASH_SIZE
 from . import layout
 
-if False:
+if TYPE_CHECKING:
     from typing import Any, Awaitable
     from trezor.enums import AmountUnit
 
@@ -36,6 +38,8 @@ class UiConfirm:
     def confirm_dialog(self, ctx: wire.Context) -> Awaitable[Any]:
         raise NotImplementedError
 
+    __eq__ = utils.obj_eq  # type: ignore
+
 
 class UiConfirmOutput(UiConfirm):
     def __init__(self, output: TxOutput, coin: CoinInfo, amount_unit: AmountUnit):
@@ -46,8 +50,6 @@ class UiConfirmOutput(UiConfirm):
     def confirm_dialog(self, ctx: wire.Context) -> Awaitable[Any]:
         return layout.confirm_output(ctx, self.output, self.coin, self.amount_unit)
 
-    __eq__ = utils.obj_eq
-
 
 class UiConfirmDecredSSTXSubmission(UiConfirm):
     def __init__(self, output: TxOutput, coin: CoinInfo, amount_unit: AmountUnit):
@@ -60,8 +62,6 @@ class UiConfirmDecredSSTXSubmission(UiConfirm):
             ctx, self.output, self.coin, self.amount_unit
         )
 
-    __eq__ = utils.obj_eq
-
 
 class UiConfirmReplacement(UiConfirm):
     def __init__(self, description: str, txid: bytes):
@@ -71,8 +71,6 @@ class UiConfirmReplacement(UiConfirm):
     def confirm_dialog(self, ctx: wire.Context) -> Awaitable[Any]:
         return layout.confirm_replacement(ctx, self.description, self.txid)
 
-    __eq__ = utils.obj_eq
-
 
 class UiConfirmModifyOutput(UiConfirm):
     def __init__(
@@ -92,8 +90,6 @@ class UiConfirmModifyOutput(UiConfirm):
             ctx, self.txo, self.orig_txo, self.coin, self.amount_unit
         )
 
-    __eq__ = utils.obj_eq
-
 
 class UiConfirmModifyFee(UiConfirm):
     def __init__(
@@ -113,8 +109,6 @@ class UiConfirmModifyFee(UiConfirm):
             ctx, self.user_fee_change, self.total_fee_new, self.coin, self.amount_unit
         )
 
-    __eq__ = utils.obj_eq
-
 
 class UiConfirmTotal(UiConfirm):
     def __init__(
@@ -130,8 +124,6 @@ class UiConfirmTotal(UiConfirm):
             ctx, self.spending, self.fee, self.coin, self.amount_unit
         )
 
-    __eq__ = utils.obj_eq
-
 
 class UiConfirmJointTotal(UiConfirm):
     def __init__(
@@ -147,8 +139,6 @@ class UiConfirmJointTotal(UiConfirm):
             ctx, self.spending, self.total, self.coin, self.amount_unit
         )
 
-    __eq__ = utils.obj_eq
-
 
 class UiConfirmFeeOverThreshold(UiConfirm):
     def __init__(self, fee: int, coin: CoinInfo, amount_unit: AmountUnit):
@@ -161,8 +151,6 @@ class UiConfirmFeeOverThreshold(UiConfirm):
             ctx, self.fee, self.coin, self.amount_unit
         )
 
-    __eq__ = utils.obj_eq
-
 
 class UiConfirmChangeCountOverThreshold(UiConfirm):
     def __init__(self, change_count: int):
@@ -171,8 +159,6 @@ class UiConfirmChangeCountOverThreshold(UiConfirm):
     def confirm_dialog(self, ctx: wire.Context) -> Awaitable[Any]:
         return layout.confirm_change_count_over_threshold(ctx, self.change_count)
 
-    __eq__ = utils.obj_eq
-
 
 class UiConfirmForeignAddress(UiConfirm):
     def __init__(self, address_n: list):
@@ -181,8 +167,6 @@ class UiConfirmForeignAddress(UiConfirm):
     def confirm_dialog(self, ctx: wire.Context) -> Awaitable[Any]:
         return paths.show_path_warning(ctx, self.address_n)
 
-    __eq__ = utils.obj_eq
-
 
 class UiConfirmNonDefaultLocktime(UiConfirm):
     def __init__(self, lock_time: int, lock_time_disabled: bool):
@@ -194,8 +178,6 @@ class UiConfirmNonDefaultLocktime(UiConfirm):
             ctx, self.lock_time, self.lock_time_disabled
         )
 
-    __eq__ = utils.obj_eq
-
 
 def confirm_output(output: TxOutput, coin: CoinInfo, amount_unit: AmountUnit) -> Awaitable[None]:  # type: ignore
     return (yield UiConfirmOutput(output, coin, amount_unit))
@@ -250,9 +232,9 @@ def request_tx_meta(tx_req: TxRequest, coin: CoinInfo, tx_hash: bytes | None = N
     return sanitize_tx_meta(ack.tx, coin)
 
 
-def request_tx_extra_data(  # type: ignore
+def request_tx_extra_data(
     tx_req: TxRequest, offset: int, size: int, tx_hash: bytes | None = None
-) -> Awaitable[bytearray]:
+) -> Awaitable[bytearray]:  # type: ignore
     assert tx_req.details is not None
     tx_req.request_type = RequestType.TXEXTRADATA
     tx_req.details.extra_data_offset = offset
@@ -327,7 +309,8 @@ def _clear_tx_request(tx_req: TxRequest) -> None:
     tx_req.details.extra_data_offset = None
     tx_req.serialized.signature = None
     tx_req.serialized.signature_index = None
-    # mypy thinks serialized_tx is `bytes`, which doesn't support indexed assignment
+    # typechecker thinks serialized_tx is `bytes`, which is immutable
+    # we know that it is `bytearray` in reality
     tx_req.serialized.serialized_tx[:] = bytes()  # type: ignore
 
 

core/src/apps/bitcoin/sign_tx/layout.py

@@ -1,4 +1,5 @@
 from micropython import const
+from typing import TYPE_CHECKING
 from ubinascii import hexlify
 
 from trezor import utils
@@ -13,7 +14,7 @@ if not utils.BITCOIN_ONLY:
     from trezor.ui.layouts.tt import altcoin
 
 
-if False:
+if TYPE_CHECKING:
     from trezor import wire
     from trezor.messages import TxOutput
     from trezor.ui.layouts import LayoutType

core/src/apps/bitcoin/sign_tx/matchcheck.py

@@ -1,17 +1,19 @@
+from typing import TYPE_CHECKING
+
 from trezor import wire
 from trezor.utils import ensure
 
 from .. import multisig
 from ..common import BIP32_WALLET_DEPTH
 
-if False:
+if TYPE_CHECKING:
     from typing import Any, Generic, TypeVar
 
     from trezor.messages import TxInput, TxOutput
 
     T = TypeVar("T")
 else:
-    # mypy cheat: Generic[T] will be `object` which is a valid parent type
+    # typechecker cheat: Generic[T] will be `object` which is a valid parent type
     Generic = [object]  # type: ignore
     T = 0  # type: ignore
 

core/src/apps/bitcoin/sign_tx/sig_hasher.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor.crypto.hashlib import sha256
 from trezor.messages import PrevTx, SignTx, TxInput, TxOutput
 from trezor.utils import HashWriter
@@ -7,7 +9,7 @@ from apps.common import coininfo
 from .. import scripts, writers
 from ..common import tagged_hashwriter
 
-if False:
+if TYPE_CHECKING:
     from typing import Protocol, Sequence
     from ..common import SigHashType
 

core/src/apps/bitcoin/sign_tx/tx_info.py

@@ -1,4 +1,5 @@
 from micropython import const
+from typing import TYPE_CHECKING
 
 from trezor import wire
 from trezor.crypto.hashlib import sha256
@@ -8,7 +9,7 @@ from .. import common, writers
 from ..common import BIP32_WALLET_DEPTH, input_is_external
 from .matchcheck import MultisigFingerprintChecker, WalletPathChecker
 
-if False:
+if TYPE_CHECKING:
     from typing import Protocol
     from trezor.messages import (
         PrevTx,
@@ -21,7 +22,7 @@ if False:
     from apps.common.coininfo import CoinInfo
 
     class Signer(Protocol):
-        coin = ...  # type: CoinInfo
+        coin: CoinInfo
 
         def create_hash_writer(self) -> HashWriter:
             ...

core/src/apps/bitcoin/sign_tx/tx_weight.py

@@ -6,13 +6,14 @@
 # https://github.com/trezor/trezor-mcu/commit/e1fa7af1da79e86ccaae5f3cd2a6c4644f546f8a
 
 from micropython import const
+from typing import TYPE_CHECKING
 
 from trezor import wire
 from trezor.enums import InputScriptType
 
 from .. import common, ownership
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import TxInput
 
 # transaction header size: 4 byte version

core/src/apps/bitcoin/sign_tx/zcash.py

@@ -1,5 +1,6 @@
 import ustruct as struct
 from micropython import const
+from typing import TYPE_CHECKING
 
 from trezor import wire
 from trezor.crypto.hashlib import blake2b
@@ -23,7 +24,7 @@ from ..writers import (
 from . import approvers, helpers
 from .bitcoinlike import Bitcoinlike
 
-if False:
+if TYPE_CHECKING:
     from typing import Sequence
     from apps.common import coininfo
     from .sig_hasher import SigHasher
@@ -119,7 +120,7 @@ class Zcashlike(Bitcoinlike):
         tx: SignTx,
         keychain: Keychain,
         coin: CoinInfo,
-        approver: approvers.Approver,
+        approver: approvers.Approver | None,
     ) -> None:
         ensure(coin.overwintered)
         super().__init__(tx, keychain, coin, approver)

core/src/apps/bitcoin/verification.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import utils, wire
 from trezor.crypto import der
 from trezor.crypto.curve import bip340, secp256k1
@@ -19,7 +21,7 @@ from .scripts import (
     write_input_script_p2wsh_in_p2sh,
 )
 
-if False:
+if TYPE_CHECKING:
     from typing import Sequence
     from apps.common.coininfo import CoinInfo
 

core/src/apps/bitcoin/verify_message.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import wire
 from trezor.crypto.curve import secp256k1
 from trezor.enums import InputScriptType
@@ -15,7 +17,7 @@ from .addresses import (
     address_to_cashaddr,
 )
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import VerifyMessage
 
 

core/src/apps/bitcoin/writers.py

@@ -1,4 +1,5 @@
 from micropython import const
+from typing import TYPE_CHECKING
 
 from trezor.crypto.hashlib import sha256
 from trezor.utils import ensure
@@ -14,7 +15,7 @@ from apps.common.writers import (  # noqa: F401
     write_uint64_le,
 )
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import (
         PrevInput,
         PrevOutput,

core/src/apps/cardano/address.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor.crypto import base58
 from trezor.enums import CardanoAddressType
 
@@ -15,7 +17,7 @@ from .helpers.paths import SCHEMA_STAKING_ANY_ACCOUNT
 from .helpers.utils import get_public_key_hash, variable_length_encode
 from .seed import is_byron_path, is_shelley_path
 
-if False:
+if TYPE_CHECKING:
     from typing import Any
 
     from trezor.messages import (

core/src/apps/cardano/auxiliary_data.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor.crypto import hashlib
 from trezor.crypto.curve import ed25519
 from trezor.enums import CardanoAddressType, CardanoTxAuxiliaryDataSupplementType
@@ -16,7 +18,7 @@ from .helpers.paths import SCHEMA_STAKING_ANY_ACCOUNT
 from .helpers.utils import derive_public_key
 from .layout import confirm_catalyst_registration, show_auxiliary_data_hash
 
-if False:
+if TYPE_CHECKING:
     from typing import Union
     from trezor import wire
 

core/src/apps/cardano/byron_address.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import log
 from trezor.crypto import crc, hashlib
 
@@ -6,7 +8,7 @@ from apps.common import cbor
 from .helpers import INVALID_ADDRESS, NETWORK_MISMATCH, protocol_magics
 from .helpers.utils import derive_public_key
 
-if False:
+if TYPE_CHECKING:
     from . import seed
 
 PROTOCOL_MAGIC_KEY = 2

core/src/apps/cardano/certificates.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor.enums import (
     CardanoCertificateType,
     CardanoPoolRelayType,
@@ -15,7 +17,7 @@ from .helpers import ADDRESS_KEY_HASH_SIZE, INVALID_CERTIFICATE, LOVELACE_MAX_SU
 from .helpers.paths import SCHEMA_STAKING_ANY_ACCOUNT
 from .helpers.utils import validate_stake_credential
 
-if False:
+if TYPE_CHECKING:
     from typing import Any
 
     from trezor.messages import (

core/src/apps/cardano/get_address.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import log, wire
 from trezor.messages import CardanoAddress
 
@@ -7,7 +9,7 @@ from .helpers.credential import Credential, should_show_address_credentials
 from .layout import show_cardano_address, show_credentials
 from .sign_tx import validate_network_info
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import (
         CardanoAddressParametersType,
         CardanoGetAddress,

core/src/apps/cardano/get_native_script_hash.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import wire
 from trezor.enums import CardanoNativeScriptHashDisplayFormat
 from trezor.messages import CardanoNativeScriptHash
@@ -5,7 +7,7 @@ from trezor.messages import CardanoNativeScriptHash
 from . import native_script, seed
 from .layout import show_native_script, show_script_hash
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import CardanoGetNativeScriptHash
 
 

core/src/apps/cardano/get_public_key.py

@@ -1,3 +1,4 @@
+from typing import TYPE_CHECKING
 from ubinascii import hexlify
 
 from trezor import log, wire
@@ -10,7 +11,7 @@ from . import seed
 from .helpers.paths import SCHEMA_MINT, SCHEMA_PUBKEY
 from .helpers.utils import derive_public_key
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import CardanoGetPublicKey
 
 

core/src/apps/cardano/helpers/account_path_check.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from ...common.paths import HARDENED
 from ..seed import is_byron_path, is_minting_path, is_multisig_path, is_shelley_path
 from . import (
@@ -9,7 +11,7 @@ from . import (
 from .paths import ACCOUNT_PATH_INDEX, ACCOUNT_PATH_LENGTH
 from .utils import to_account_path
 
-if False:
+if TYPE_CHECKING:
     from trezor import wire
     from trezor.messages import (
         CardanoPoolOwner,

core/src/apps/cardano/helpers/credential.py

@@ -1,10 +1,12 @@
+from typing import TYPE_CHECKING
+
 from trezor.enums import CardanoAddressType
 
 from ...common.paths import address_n_to_str
 from .paths import CHAIN_STAKING_KEY, SCHEMA_PAYMENT, SCHEMA_STAKING
 from .utils import format_key_hash, format_script_hash, to_account_path
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import (
         CardanoBlockchainPointerType,
         CardanoAddressParametersType,

core/src/apps/cardano/helpers/hash_builder_collection.py

@@ -1,6 +1,8 @@
+from typing import TYPE_CHECKING
+
 from apps.common import cbor
 
-if False:
+if TYPE_CHECKING:
     from typing import Any, Generic, TypeVar
     from trezor.utils import HashContext
 

core/src/apps/cardano/helpers/utils.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor.crypto import hashlib
 from trezor.enums import CardanoTxSigningMode
 
@@ -10,7 +12,7 @@ from apps.common.seed import remove_ed25519_prefix
 
 from . import ADDRESS_KEY_HASH_SIZE, SCRIPT_HASH_SIZE, bech32
 
-if False:
+if TYPE_CHECKING:
     from trezor import wire
     from .. import seed
 

core/src/apps/cardano/layout.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import ui
 from trezor.enums import (
     ButtonRequestType,
@@ -35,7 +37,7 @@ from .helpers.utils import (
 )
 from .seed import is_minting_path, is_multisig_path
 
-if False:
+if TYPE_CHECKING:
     from trezor import wire
     from trezor.messages import (
         CardanoNativeScript,

core/src/apps/cardano/native_script.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor.crypto import hashlib
 from trezor.enums import CardanoAddressType, CardanoNativeScriptType
 
@@ -12,7 +14,7 @@ from .helpers.paths import SCHEMA_MINT
 from .helpers.utils import get_public_key_hash
 from .seed import Keychain, is_multisig_path
 
-if False:
+if TYPE_CHECKING:
     from typing import Any
 
     from trezor.messages import CardanoNativeScript

core/src/apps/cardano/seed.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from storage import cache, device
 from trezor import wire
 from trezor.crypto import bip32, cardano
@@ -8,7 +10,7 @@ from apps.common.seed import derive_and_store_roots, get_seed
 
 from .helpers import paths
 
-if False:
+if TYPE_CHECKING:
     from typing import Callable, Awaitable, TypeVar, Union
 
     from apps.common.paths import Bip32Path

core/src/apps/cardano/sign_tx.py

@@ -1,4 +1,5 @@
 from micropython import const
+from typing import TYPE_CHECKING
 
 from trezor import log, wire
 from trezor.crypto import hashlib
@@ -105,7 +106,7 @@ from .layout import (
 )
 from .seed import is_byron_path, is_multisig_path, is_shelley_path
 
-if False:
+if TYPE_CHECKING:
     from typing import Any, Union
     from apps.common.paths import PathSchema
 

core/src/apps/common/authorization.py

@@ -1,11 +1,10 @@
+from typing import Iterable
+
 import storage.cache
 from trezor import protobuf
 from trezor.enums import MessageType
 from trezor.utils import ensure
 
-if False:
-    from typing import Iterable
-
 WIRE_TYPES: dict[int, tuple[int, ...]] = {
     MessageType.AuthorizeCoinJoin: (MessageType.SignTx, MessageType.GetOwnershipProof),
 }
@@ -21,7 +20,7 @@ def set(auth_message: protobuf.MessageType) -> None:
     # only wire-level messages can be stored as authorization
     # (because only wire-level messages have wire_type, which we use as identifier)
     ensure(auth_message.MESSAGE_WIRE_TYPE is not None)
-    assert auth_message.MESSAGE_WIRE_TYPE is not None  # so that mypy knows as well
+    assert auth_message.MESSAGE_WIRE_TYPE is not None  # so that typechecker knows too
     storage.cache.set(
         storage.cache.APP_COMMON_AUTHORIZATION_TYPE,
         auth_message.MESSAGE_WIRE_TYPE.to_bytes(2, "big"),

core/src/apps/common/cbor.py

@@ -4,12 +4,13 @@ Minimalistic CBOR implementation, supports only what we need in cardano.
 
 import ustruct as struct
 from micropython import const
+from typing import TYPE_CHECKING
 
 from trezor import log, utils
 
 from . import readers
 
-if False:
+if TYPE_CHECKING:
     from typing import Any, Generic, Iterator, Tuple, TypeVar, Union
 
     K = TypeVar("K")
@@ -17,7 +18,7 @@ if False:
     Value = Any
     CborSequence = Union[list[Value], Tuple[Value, ...]]
 else:
-    # mypy cheat: Generic[K, V] will be `object` which is a valid parent type
+    # typechecker cheat: Generic[K, V] will be `object` which is a valid parent type
     Generic = {(0, 0): object}  # type: ignore
     K = V = 0  # type: ignore
 

core/src/apps/common/coininfo.py

@@ -1,12 +1,11 @@
 # generated from coininfo.py.mako
 # do not edit manually!
+from typing import Any
+
 from trezor import utils
 from trezor.crypto.base58 import blake256d_32, groestl512d_32, keccak_32, sha256d_32
 from trezor.crypto.scripts import blake256_ripemd160, sha256_ripemd160
 
-if False:
-    from typing import Any, Type
-
 # flake8: noqa
 
 
@@ -69,7 +68,7 @@ class CoinInfo:
         if curve_name == "secp256k1-groestl":
             self.b58_hash = groestl512d_32
             self.sign_hash_double = False
-            self.script_hash: Type[utils.HashContext] = sha256_ripemd160
+            self.script_hash: type[utils.HashContext] = sha256_ripemd160
         elif curve_name == "secp256k1-decred":
             self.b58_hash = blake256d_32
             self.sign_hash_double = False

core/src/apps/common/coininfo.py.mako

@@ -1,12 +1,11 @@
 # generated from coininfo.py.mako
 # do not edit manually!
+from typing import Any
+
 from trezor import utils
 from trezor.crypto.base58 import blake256d_32, groestl512d_32, keccak_32, sha256d_32
 from trezor.crypto.scripts import blake256_ripemd160, sha256_ripemd160
 
-if False:
-    from typing import Any, Type
-
 # flake8: noqa
 
 
@@ -69,7 +68,7 @@ class CoinInfo:
         if curve_name == "secp256k1-groestl":
             self.b58_hash = groestl512d_32
             self.sign_hash_double = False
-            self.script_hash: Type[utils.HashContext] = sha256_ripemd160
+            self.script_hash: type[utils.HashContext] = sha256_ripemd160
         elif curve_name == "secp256k1-decred":
             self.b58_hash = blake256d_32
             self.sign_hash_double = False

core/src/apps/common/keychain.py

@@ -1,4 +1,5 @@
 import sys
+from typing import TYPE_CHECKING
 
 from trezor import wire
 from trezor.crypto import bip32
@@ -6,7 +7,7 @@ from trezor.crypto import bip32
 from . import paths, safety_checks
 from .seed import Slip21Node, get_seed
 
-if False:
+if TYPE_CHECKING:
     from typing import (
         Any,
         Awaitable,

core/src/apps/common/paths.py

@@ -1,8 +1,9 @@
 from micropython import const
+from typing import TYPE_CHECKING
 
 HARDENED = const(0x8000_0000)
 
-if False:
+if TYPE_CHECKING:
     from typing import (
         Any,
         Callable,
@@ -17,7 +18,7 @@ if False:
 
     Bip32Path = Sequence[int]
     Slip21Path = Sequence[bytes]
-    PathType = TypeVar("PathType", Bip32Path, Slip21Path)
+    PathType = TypeVar("PathType", Bip32Path, Slip21Path, contravariant=True)
 
     class PathSchemaType(Protocol):
         def match(self, path: Bip32Path) -> bool:
@@ -105,7 +106,7 @@ class PathSchema:
     _EMPTY_TUPLE = ()
 
     @staticmethod
-    def _parse_hardened(s: str) -> int:
+    def _parse_hardened(s: str | int) -> int:
         return int(s) | HARDENED
 
     @staticmethod
@@ -259,7 +260,8 @@ class PathSchema:
                     prime = "'" if a & HARDENED else ""
                     components.append(f"[{unharden(a)}-{unharden(b)}]{prime}")
                 else:
-                    # mypy thinks component is a Contanier but we're using it as a Collection.
+                    # typechecker thinks component is a Contanier but we're using it
+                    # as a Collection.
                     # Which in practice it is, the only non-Collection is Interval.
                     # But we're not going to introduce an additional type requirement
                     # for the sake of __repr__ that doesn't exist in production anyway
@@ -282,25 +284,18 @@ class PathSchema:
             return "<schema:" + "/".join(components) + ">"
 
 
-class _AlwaysMatchingSchema:
+class AlwaysMatchingSchema:
     @staticmethod
     def match(path: Bip32Path) -> bool:
         return True
 
 
-class _NeverMatchingSchema:
+class NeverMatchingSchema:
     @staticmethod
     def match(path: Bip32Path) -> bool:
         return False
 
 
-# type objects _AlwaysMatchingSchema and _NeverMatching schema conform to the
-# PathSchemaType protocol, but mypy fails to recognize this due to:
-# https://github.com/python/mypy/issues/4536,
-# hence the following trickery
-AlwaysMatchingSchema: PathSchemaType = _AlwaysMatchingSchema  # type: ignore
-NeverMatchingSchema: PathSchemaType = _NeverMatchingSchema  # type: ignore
-
 # BIP-44 for basic (legacy) Bitcoin accounts, and widely used for other currencies:
 # https://github.com/bitcoin/bips/blob/master/bip-0044.mediawiki
 PATTERN_BIP44 = "m/44'/coin_type'/account'/change/address_index"

core/src/apps/common/request_pin.py

@@ -1,4 +1,5 @@
 import utime
+from typing import Any, NoReturn
 
 import storage.cache
 import storage.sd_salt
@@ -6,9 +7,6 @@ from trezor import config, wire
 
 from .sdcard import SdCardUnavailable, request_sd_salt
 
-if False:
-    from typing import Any, NoReturn
-
 
 def can_lock_device() -> bool:
     """Return True if the device has a PIN set or SD-protect enabled."""
@@ -108,7 +106,8 @@ async def verify_user_pin(
         raise RuntimeError
 
     while retry:
-        pin = await request_pin_on_device(
+        # request_pin_on_device possibly unbound
+        pin = await request_pin_on_device(  # type: ignore
             ctx, "Wrong PIN, enter again", config.get_pin_rem(), allow_cancel
         )
         if config.unlock(pin, salt):

core/src/apps/common/seed.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from storage import cache, device
 from trezor import utils, wire
 from trezor.crypto import bip32, hmac
@@ -5,7 +7,7 @@ from trezor.crypto import bip32, hmac
 from . import mnemonic
 from .passphrase import get as get_passphrase
 
-if False:
+if TYPE_CHECKING:
     from .paths import Bip32Path, Slip21Path
 
 

core/src/apps/common/signverify.py

@@ -1,3 +1,4 @@
+from typing import TYPE_CHECKING
 from ubinascii import hexlify
 
 from trezor import utils, wire
@@ -5,7 +6,7 @@ from trezor.crypto.hashlib import blake256, sha256
 
 from apps.common.writers import write_bitcoin_varint
 
-if False:
+if TYPE_CHECKING:
     from apps.common.coininfo import CoinInfo
 
 

core/src/apps/common/writers.py

@@ -1,6 +1,8 @@
+from typing import TYPE_CHECKING
+
 from trezor.utils import ensure
 
-if False:
+if TYPE_CHECKING:
     from typing import Union
     from trezor.utils import Writer
 

core/src/apps/debug/__init__.py

@@ -16,7 +16,9 @@ if __debug__:
 
     from apps import workflow_handlers
 
-    if False:
+    from typing import TYPE_CHECKING
+
+    if TYPE_CHECKING:
         from trezor.ui import Layout
         from trezor.messages import (
             DebugLinkDecision,

core/src/apps/debug/load_device.py

@@ -3,13 +3,13 @@ import storage.device
 from trezor import config, wire
 from trezor.crypto import bip39, slip39
 from trezor.enums import BackupType
-from trezor.messages import Success
+from trezor.messages import LoadDevice, Success
 from trezor.ui.layouts import confirm_action
 
 from apps.management import backup_types
 
 
-async def load_device(ctx, msg):
+async def load_device(ctx: wire.Context, msg: LoadDevice) -> Success:
     word_count = _validate(msg)
     is_slip39 = backup_types.is_slip39_word_count(word_count)
 
@@ -42,7 +42,7 @@ async def load_device(ctx, msg):
         needs_backup=msg.needs_backup is True,
         no_backup=msg.no_backup is True,
     )
-    storage.device.set_passphrase_enabled(msg.passphrase_protection)
+    storage.device.set_passphrase_enabled(bool(msg.passphrase_protection))
     storage.device.set_label(msg.label or "")
     if msg.pin:
         config.change_pin("", msg.pin, None, None)
@@ -50,7 +50,7 @@ async def load_device(ctx, msg):
     return Success(message="Device loaded")
 
 
-def _validate(msg) -> int:
+def _validate(msg: LoadDevice) -> int:
     if storage.device.is_initialized():
         raise wire.UnexpectedMessage("Already initialized")
 
@@ -67,7 +67,7 @@ def _validate(msg) -> int:
     return word_count
 
 
-async def _warn(ctx: wire.Context):
+async def _warn(ctx: wire.Context) -> None:
     await confirm_action(
         ctx,
         "warn_loading_seed",

core/src/apps/eos/actions/__init__.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor.crypto.hashlib import sha256
 from trezor.messages import EosTxActionAck, EosTxActionRequest
 from trezor.utils import HashWriter
@@ -5,7 +7,7 @@ from trezor.utils import HashWriter
 from .. import helpers, writers
 from . import layout
 
-if False:
+if TYPE_CHECKING:
     from trezor import wire
     from trezor.utils import Writer
 
@@ -22,44 +24,57 @@ async def process_action(
     w = bytearray()
     if account == "eosio":
         if name == "buyram":
+            assert action.buy_ram is not None  # check_action
             await layout.confirm_action_buyram(ctx, action.buy_ram)
             writers.write_action_buyram(w, action.buy_ram)
         elif name == "buyrambytes":
+            assert action.buy_ram_bytes is not None  # check_action
             await layout.confirm_action_buyrambytes(ctx, action.buy_ram_bytes)
             writers.write_action_buyrambytes(w, action.buy_ram_bytes)
         elif name == "sellram":
+            assert action.sell_ram is not None  # check_action
             await layout.confirm_action_sellram(ctx, action.sell_ram)
             writers.write_action_sellram(w, action.sell_ram)
         elif name == "delegatebw":
+            assert action.delegate is not None  # check_action
             await layout.confirm_action_delegate(ctx, action.delegate)
             writers.write_action_delegate(w, action.delegate)
         elif name == "undelegatebw":
+            assert action.undelegate is not None  # check_action
             await layout.confirm_action_undelegate(ctx, action.undelegate)
             writers.write_action_undelegate(w, action.undelegate)
         elif name == "refund":
+            assert action.refund is not None  # check_action
             await layout.confirm_action_refund(ctx, action.refund)
             writers.write_action_refund(w, action.refund)
         elif name == "voteproducer":
+            assert action.vote_producer is not None  # check_action
             await layout.confirm_action_voteproducer(ctx, action.vote_producer)
             writers.write_action_voteproducer(w, action.vote_producer)
         elif name == "updateauth":
+            assert action.update_auth is not None  # check_action
             await layout.confirm_action_updateauth(ctx, action.update_auth)
             writers.write_action_updateauth(w, action.update_auth)
         elif name == "deleteauth":
+            assert action.delete_auth is not None  # check_action
             await layout.confirm_action_deleteauth(ctx, action.delete_auth)
             writers.write_action_deleteauth(w, action.delete_auth)
         elif name == "linkauth":
+            assert action.link_auth is not None  # check_action
             await layout.confirm_action_linkauth(ctx, action.link_auth)
             writers.write_action_linkauth(w, action.link_auth)
         elif name == "unlinkauth":
+            assert action.unlink_auth is not None  # check_action
             await layout.confirm_action_unlinkauth(ctx, action.unlink_auth)
             writers.write_action_unlinkauth(w, action.unlink_auth)
         elif name == "newaccount":
+            assert action.new_account is not None  # check_action
             await layout.confirm_action_newaccount(ctx, action.new_account)
             writers.write_action_newaccount(w, action.new_account)
         else:
             raise ValueError("Unrecognized action type for eosio")
     elif name == "transfer":
+        assert action.transfer is not None  # check_action
         await layout.confirm_action_transfer(ctx, action.transfer, account)
         writers.write_action_transfer(w, action.transfer)
     else:
@@ -72,6 +87,7 @@ async def process_action(
 async def process_unknown_action(
     ctx: wire.Context, w: Writer, action: EosTxActionAck
 ) -> None:
+    assert action.unknown is not None
     checksum = HashWriter(sha256())
     writers.write_uvarint(checksum, action.unknown.data_size)
     checksum.extend(action.unknown.data_chunk)

core/src/apps/eos/actions/layout.py

@@ -1,11 +1,12 @@
-from trezor import ui
+from typing import TYPE_CHECKING
+
+from trezor import ui, wire
 from trezor.enums import ButtonRequestType
 from trezor.ui.layouts import confirm_properties
 
 from .. import helpers
 
-if False:
-    from trezor import wire
+if TYPE_CHECKING:
     from trezor.messages import (
         EosActionBuyRam,
         EosActionBuyRamBytes,
@@ -23,6 +24,7 @@ if False:
         EosActionVoteProducer,
         EosAuthorization,
     )
+    from trezor.ui.layouts import PropertyType
 
 
 async def confirm_action_buyram(ctx: wire.Context, msg: EosActionBuyRam) -> None:
@@ -194,7 +196,7 @@ async def confirm_action_transfer(
 async def confirm_action_updateauth(
     ctx: wire.Context, msg: EosActionUpdateAuth
 ) -> None:
-    props = [
+    props: list[PropertyType] = [
         ("Account:", helpers.eos_name_to_string(msg.account)),
         ("Permission:", helpers.eos_name_to_string(msg.permission)),
         ("Parent:", helpers.eos_name_to_string(msg.parent)),
@@ -262,7 +264,7 @@ async def confirm_action_unlinkauth(
 async def confirm_action_newaccount(
     ctx: wire.Context, msg: EosActionNewAccount
 ) -> None:
-    props = [
+    props: list[PropertyType] = [
         ("Creator:", helpers.eos_name_to_string(msg.creator)),
         ("Name:", helpers.eos_name_to_string(msg.name)),
     ]
@@ -296,11 +298,14 @@ async def confirm_action_unknown(
     )
 
 
-def authorization_fields(auth: EosAuthorization) -> list[tuple[str, str | None]]:
-    fields = []
+def authorization_fields(auth: EosAuthorization) -> list[PropertyType]:
+    fields: list[PropertyType] = []
     fields.append(("Threshold:", str(auth.threshold)))
 
     for i, key in enumerate(auth.keys, 1):
+        if key.key is None:
+            raise wire.DataError("Key must be provided explicitly.")
+
         _key = helpers.public_key_to_wif(bytes(key.key))
         _weight = str(key.weight)
 

core/src/apps/eos/get_public_key.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import wire
 from trezor.crypto.curve import secp256k1
 from trezor.messages import EosGetPublicKey, EosPublicKey
@@ -8,7 +10,7 @@ from apps.common.keychain import Keychain, auto_keychain
 from .helpers import public_key_to_wif
 from .layout import require_get_public_key
 
-if False:
+if TYPE_CHECKING:
     from trezor.crypto import bip32
 
 

core/src/apps/eos/sign_tx.py

@@ -15,11 +15,7 @@ from .layout import require_sign_tx
 
 @auto_keychain(__name__)
 async def sign_tx(ctx: wire.Context, msg: EosSignTx, keychain: Keychain) -> EosSignedTx:
-    if msg.chain_id is None:
-        raise wire.DataError("No chain id")
-    if msg.header is None:
-        raise wire.DataError("No header")
-    if msg.num_actions is None or msg.num_actions == 0:
+    if not msg.num_actions:
         raise wire.DataError("No actions")
 
     await paths.validate_path(ctx, keychain, msg.address_n)

core/src/apps/eos/writers.py

@@ -1,3 +1,7 @@
+from typing import TYPE_CHECKING
+
+from trezor import wire
+
 from apps.common.writers import (
     write_bytes_fixed,
     write_bytes_unchecked,
@@ -8,7 +12,7 @@ from apps.common.writers import (
     write_uvarint,
 )
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import (
         EosActionBuyRam,
         EosActionBuyRamBytes,
@@ -16,6 +20,7 @@ if False:
         EosActionDelegate,
         EosActionDeleteAuth,
         EosActionLinkAuth,
+        EosActionUnlinkAuth,
         EosActionNewAccount,
         EosActionRefund,
         EosActionSellRam,
@@ -34,6 +39,8 @@ def write_auth(w: Writer, auth: EosAuthorization) -> None:
     write_uint32_le(w, auth.threshold)
     write_uvarint(w, len(auth.keys))
     for key in auth.keys:
+        if key.key is None:
+            raise wire.DataError("Key must be provided explicitly.")
         write_uvarint(w, key.type)
         write_bytes_fixed(w, key.key, 33)
         write_uint16_le(w, key.weight)
@@ -63,7 +70,7 @@ def write_action_transfer(w: Writer, msg: EosActionTransfer) -> None:
     write_uint64_le(w, msg.sender)
     write_uint64_le(w, msg.receiver)
     write_asset(w, msg.quantity)
-    write_bytes_prefixed(w, msg.memo)
+    write_bytes_prefixed(w, msg.memo.encode())
 
 
 def write_action_buyram(w: Writer, msg: EosActionBuyRam) -> None:
@@ -129,7 +136,7 @@ def write_action_linkauth(w: Writer, msg: EosActionLinkAuth) -> None:
     write_uint64_le(w, msg.requirement)
 
 
-def write_action_unlinkauth(w: Writer, msg: EosActionLinkAuth) -> None:
+def write_action_unlinkauth(w: Writer, msg: EosActionUnlinkAuth) -> None:
     write_uint64_le(w, msg.account)
     write_uint64_le(w, msg.code)
     write_uint64_le(w, msg.type)

core/src/apps/ethereum/get_address.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor.messages import EthereumAddress
 from trezor.ui.layouts import show_address
 
@@ -7,7 +9,7 @@ from . import networks
 from .helpers import address_from_bytes
 from .keychain import PATTERNS_ADDRESS, with_keychain_from_path
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import EthereumGetAddress
     from trezor.wire import Context
 

core/src/apps/ethereum/get_public_key.py

@@ -1,3 +1,4 @@
+from typing import TYPE_CHECKING
 from ubinascii import hexlify
 
 from trezor.messages import EthereumPublicKey, HDNodeType
@@ -7,7 +8,7 @@ from apps.common import coins, paths
 
 from .keychain import with_keychain_from_path
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import EthereumGetPublicKey
     from trezor.wire import Context
 

core/src/apps/ethereum/helpers.py

@@ -1,10 +1,11 @@
+from typing import TYPE_CHECKING
 from ubinascii import hexlify, unhexlify
 
 from trezor import wire
 from trezor.enums import EthereumDataType
 from trezor.messages import EthereumFieldType
 
-if False:
+if TYPE_CHECKING:
     from .networks import NetworkInfo
 
 

core/src/apps/ethereum/keychain.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import wire
 
 from apps.common import paths
@@ -5,7 +7,7 @@ from apps.common.keychain import get_keychain
 
 from . import CURVE, networks
 
-if False:
+if TYPE_CHECKING:
     from typing import Callable, Iterable, TypeVar, Union
 
     from trezor.messages import (

core/src/apps/ethereum/layout.py

@@ -1,3 +1,4 @@
+from typing import TYPE_CHECKING
 from ubinascii import hexlify
 
 from trezor import ui
@@ -17,8 +18,9 @@ from trezor.ui.layouts.tt.altcoin import confirm_total_ethereum
 from . import networks, tokens
 from .helpers import address_from_bytes, decode_typed_data, get_type_name
 
-if False:
+if TYPE_CHECKING:
     from typing import Awaitable, Iterable, Optional
+
     from trezor.wire import Context
 
 

core/src/apps/ethereum/networks.py

@@ -1,11 +1,9 @@
 # generated from networks.py.mako
 # do not edit manually!
+from typing import Iterator
 
 from apps.common.paths import HARDENED
 
-if False:
-    from typing import Iterator
-
 
 def shortcut_by_chain_id(chain_id: int) -> str:
     n = by_chain_id(chain_id)

core/src/apps/ethereum/networks.py.mako

@@ -1,11 +1,9 @@
 # generated from networks.py.mako
 # do not edit manually!
+from typing import Iterator
 
 from apps.common.paths import HARDENED
 
-if False:
-    from typing import Iterator
-
 
 def shortcut_by_chain_id(chain_id: int) -> str:
     n = by_chain_id(chain_id)

core/src/apps/ethereum/sign_message.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor.crypto.curve import secp256k1
 from trezor.crypto.hashlib import sha3_256
 from trezor.messages import EthereumMessageSignature
@@ -10,7 +12,7 @@ from apps.common.signverify import decode_message
 from .helpers import address_from_bytes
 from .keychain import PATTERNS_ADDRESS, with_keychain_from_path
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import EthereumSignMessage
     from trezor.wire import Context
 

core/src/apps/ethereum/sign_tx.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import wire
 from trezor.crypto import rlp
 from trezor.crypto.curve import secp256k1
@@ -17,7 +19,7 @@ from .layout import (
     require_confirm_unknown_token,
 )
 
-if False:
+if TYPE_CHECKING:
     from typing import Tuple
 
     from apps.common.keychain import Keychain

core/src/apps/ethereum/sign_tx_eip1559.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import wire
 from trezor.crypto import rlp
 from trezor.crypto.curve import secp256k1
@@ -16,7 +18,7 @@ from .layout import (
 )
 from .sign_tx import check_common_fields, handle_erc20, send_request_chunk
 
-if False:
+if TYPE_CHECKING:
     from typing import Tuple
 
     from trezor.messages import EthereumSignTxEIP1559

core/src/apps/ethereum/sign_typed_data.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import wire
 from trezor.crypto.curve import secp256k1
 from trezor.crypto.hashlib import sha3_256
@@ -25,7 +27,7 @@ from .layout import (
     should_show_struct,
 )
 
-if False:
+if TYPE_CHECKING:
     from apps.common.keychain import Keychain
     from trezor.wire import Context
 

core/src/apps/ethereum/verify_message.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from trezor import wire
 from trezor.crypto.curve import secp256k1
 from trezor.crypto.hashlib import sha3_256
@@ -9,7 +11,7 @@ from apps.common.signverify import decode_message
 from .helpers import address_from_bytes, bytes_from_address
 from .sign_message import message_digest
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import EthereumVerifyMessage
     from trezor.wire import Context
 

core/src/apps/homescreen/__init__.py

@@ -1,3 +1,5 @@
+from typing import Any
+
 import storage.cache
 import storage.device
 from trezor import res, ui
@@ -16,7 +18,7 @@ class HomescreenBase(ui.Layout):
             "apps/homescreen/res/bg.toif"
         )
 
-    async def __iter__(self) -> ui.ResultValue:
+    async def __iter__(self) -> Any:
         # We need to catch the ui.Cancelled exception that kills us, because that means
         # that we will need to draw on screen again after restart.
         try:

core/src/apps/management/apply_flags.py

@@ -1,9 +1,11 @@
+from typing import TYPE_CHECKING
+
 import storage.device
 from storage.device import set_flags
 from trezor import wire
 from trezor.messages import Success
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import ApplyFlags
 
 

core/src/apps/management/apply_settings.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 import storage.device
 from trezor import ui, wire
 from trezor.enums import ButtonRequestType, SafetyCheckLevel
@@ -8,7 +10,7 @@ from trezor.ui.layouts import confirm_action
 from apps.base import reload_settings_from_storage
 from apps.common import safety_checks
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import ApplySettings
 
 

core/src/apps/management/backup_device.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 import storage
 import storage.device
 from trezor import wire
@@ -7,7 +9,7 @@ from apps.common import mnemonic
 
 from .reset_device import backup_seed, layout
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import BackupDevice
 
 

core/src/apps/management/change_pin.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from storage.device import is_initialized
 from trezor import config, wire
 from trezor.messages import Success
@@ -10,7 +12,7 @@ from apps.common.request_pin import (
     request_pin_confirm,
 )
 
-if False:
+if TYPE_CHECKING:
     from typing import Awaitable
 
     from trezor.messages import ChangePin

core/src/apps/management/change_wipe_code.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from storage.device import is_initialized
 from trezor import config, ui, wire
 from trezor.messages import Success
@@ -9,7 +11,7 @@ from apps.common.request_pin import (
     request_pin_and_sd_salt,
 )
 
-if False:
+if TYPE_CHECKING:
     from typing import Awaitable
 
     from trezor.messages import ChangeWipeCode

core/src/apps/management/recovery_device/__init__.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 import storage
 import storage.device
 import storage.recovery
@@ -14,7 +16,7 @@ from apps.common.request_pin import (
 
 from .homescreen import recovery_homescreen, recovery_process
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import RecoveryDevice
 
 

core/src/apps/management/recovery_device/layout.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 import storage.recovery
 from trezor import ui, wire
 from trezor.enums import ButtonRequestType
@@ -15,7 +17,7 @@ from .. import backup_types
 from . import word_validity
 from .recover import RecoveryAborted
 
-if False:
+if TYPE_CHECKING:
     from typing import Callable
     from trezor.enums import BackupType
 

core/src/apps/management/recovery_device/recover.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 import storage.recovery
 import storage.recovery_shares
 from trezor.crypto import bip39, slip39
@@ -5,7 +7,7 @@ from trezor.errors import MnemonicError
 
 from .. import backup_types
 
-if False:
+if TYPE_CHECKING:
     from trezor.enums import BackupType
     from typing import Union
 
@@ -91,7 +93,7 @@ def process_slip39(words: str) -> tuple[bytes | None, slip39.Share]:
     return secret, share
 
 
-if False:
+if TYPE_CHECKING:
     Slip39State = Union[tuple[int, BackupType], tuple[None, None]]
 
 

core/src/apps/management/reset_device/__init__.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 import storage
 import storage.device
 from trezor import config, wire
@@ -14,7 +16,7 @@ from . import layout
 if __debug__:
     import storage.debug
 
-if False:
+if TYPE_CHECKING:
     from trezor.messages import ResetDevice
 
 _DEFAULT_BACKUP_TYPE = BackupType.Bip39