refactor(core): Move _get_fee_rate_str() to common and optionally add coin shortcut.

[no changelog]

core/src/apps/bitcoin/common.py

@@ -6,6 +6,7 @@ from trezor.crypto import bech32, bip32, der
 from trezor.crypto.curve import bip340, secp256k1
 from trezor.crypto.hashlib import sha256
 from trezor.enums import InputScriptType, OutputScriptType
+from trezor.strings import format_amount
 from trezor.utils import HashWriter, ensure
 
 if TYPE_CHECKING:
@@ -179,3 +180,20 @@ def tagged_hashwriter(tag: bytes) -> HashWriter:
     ctx = sha256(tag_digest)
     ctx.update(tag_digest)
     return HashWriter(ctx)
+
+
+def format_fee_rate(
+    fee_rate: float, coin: CoinInfo, include_shortcut: bool = False
+) -> str:
+    # Use format_amount to get correct thousands separator -- micropython's built-in
+    # formatting doesn't add thousands sep to floating point numbers.
+    # We multiply by 100 to get a fixed-point integer with two decimal places,
+    # and add 0.5 to round to the nearest integer.
+    fee_rate_formatted = format_amount(int(fee_rate * 100 + 0.5), 2)
+
+    if include_shortcut and coin.coin_shortcut != "BTC":
+        shortcut = " " + coin.coin_shortcut
+    else:
+        shortcut = ""
+
+    return f"{fee_rate_formatted} sat{shortcut}/{'v' if coin.segwit else ''}B"

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

@@ -8,6 +8,7 @@ from trezor.strings import format_amount, format_timestamp
 from trezor.ui import layouts
 
 from .. import addresses
+from ..common import format_fee_rate
 from . import omni
 
 if not utils.BITCOIN_ONLY:
@@ -165,7 +166,7 @@ async def confirm_modify_fee(
         user_fee_change,
         format_coin_amount(abs(user_fee_change), coin, amount_unit),
         format_coin_amount(total_fee_new, coin, amount_unit),
-        fee_rate_amount=_get_fee_rate_str(fee_rate, coin),
+        fee_rate_amount=format_fee_rate(fee_rate, coin) if fee_rate >= 0 else None,
     )
 
 
@@ -183,18 +184,6 @@ async def confirm_joint_total(
     )
 
 
-def _get_fee_rate_str(fee_rate: float, coin: CoinInfo) -> str | None:
-    if fee_rate >= 0:
-        # Use format_amount to get correct thousands separator -- micropython's built-in
-        # formatting doesn't add thousands sep to floating point numbers.
-        # We multiply by 100 to get a fixed-point integer with two decimal places,
-        # and add 0.5 to round to the nearest integer.
-        fee_rate_formatted = format_amount(int(fee_rate * 100 + 0.5), 2)
-        return f"({fee_rate_formatted} sat/{'v' if coin.segwit else ''}B)"
-    else:
-        return None
-
-
 async def confirm_total(
     ctx: wire.Context,
     spending: int,
@@ -207,7 +196,7 @@ async def confirm_total(
         ctx,
         total_amount=format_coin_amount(spending, coin, amount_unit),
         fee_amount=format_coin_amount(fee, coin, amount_unit),
-        fee_rate_amount=_get_fee_rate_str(fee_rate, coin),
+        fee_rate_amount=format_fee_rate(fee_rate, coin) if fee_rate >= 0 else None,
     )
 
 

core/src/trezor/ui/layouts/tt/__init__.py

@@ -886,7 +886,7 @@ async def confirm_total(
     text.bold(fee_amount)
 
     if fee_rate_amount is not None:
-        text.normal("\n" + fee_rate_amount)
+        text.normal(f"\n({fee_rate_amount})")
 
     await raise_if_cancelled(interact(ctx, HoldToConfirm(text), br_type, br_code))
 
@@ -999,7 +999,7 @@ async def confirm_modify_fee(
     text.normal("Transaction fee:\n")
     text.bold(total_fee_new)
     if fee_rate_amount is not None:
-        text.normal("\n" + fee_rate_amount)
+        text.normal(f"\n({fee_rate_amount})")
     await raise_if_cancelled(
         interact(ctx, HoldToConfirm(text), "modify_fee", ButtonRequestType.SignTx)
     )