feat(tests): allow for coverage report even when emulator is controlled by the tests

Allowing tests to specify the profiling wrapper over the emulator
it is starting.

[no changelog]

ci/test.yml

@@ -57,12 +57,12 @@ core device test:
   needs:
     - core unix frozen debug build
   variables:
-    TREZOR_PROFILING: 1
+    TREZOR_PROFILING: 1  # so that we get coverage data
     MULTICORE: 4  # more could interfere with other jobs
   script:
     - $NIX_SHELL --run "poetry run make -C core test_emu_ui_multicore | ts -s"
   after_script:
-    - mv core/src/.coverage core/.coverage.test_emu
+    - mv core/src/.coverage.* core  # there will be more coverage files (one per core)
     - mv tests/ui_tests/reports/test/ test_ui_report
     - $NIX_SHELL --run "poetry run python ci/prepare_ui_artifacts.py | ts -s"
     - diff -u tests/ui_tests/fixtures.json tests/ui_tests/fixtures.suggestion.json

tests/conftest.py

@@ -17,6 +17,7 @@
 from __future__ import annotations
 
 import os
+from pathlib import Path
 from typing import TYPE_CHECKING, Generator
 
 import pytest
@@ -37,6 +38,10 @@ if TYPE_CHECKING:
     from _pytest.config.argparsing import Parser
     from _pytest.terminal import TerminalReporter
 
+
+HERE = Path(__file__).resolve().parent
+
+
 # So that we see details of failed asserts from this module
 pytest.register_assert_rewrite("tests.common")
 
@@ -83,8 +88,23 @@ def emulator(request: pytest.FixtureRequest) -> Generator["Emulator", None, None
         # 1. normal link, 2. debug link and 3. webauthn fake interface
         return 20000 + int(worker_id[2:]) * 3
 
+    # So that we can generate coverage reports
+    profiling = os.environ.get("TREZOR_PROFILING") == "1"
+    if profiling:
+        core_dir = HERE.parent / "core"
+        profiling_wrapper = core_dir / "prof" / "prof.py"
+        main_args = [str(profiling_wrapper)]
+        # So that the coverage reports have the correct paths
+        os.environ["TREZOR_SRC"] = str(core_dir / "src")
+    else:
+        main_args = ["-m", "main"]
+
     with EmulatorWrapper(
-        model, port=_get_port(), headless=True, auto_interact=not interact
+        model,
+        port=_get_port(),
+        headless=True,
+        auto_interact=not interact,
+        main_args=main_args,
     ) as emu:
         yield emu
 

tests/emulators.py

@@ -17,7 +17,7 @@
 import tempfile
 from collections import defaultdict
 from pathlib import Path
-from typing import Dict, List, Optional, Tuple
+from typing import Dict, List, Optional, Sequence, Tuple
 
 from trezorlib._internal.emulator import CoreEmulator, Emulator, LegacyEmulator
 
@@ -75,6 +75,7 @@ class EmulatorWrapper:
         port: Optional[int] = None,
         headless: bool = True,
         auto_interact: bool = True,
+        main_args: Sequence[str] = ("-m", "main"),
     ) -> None:
         if tag is not None:
             executable = filename_from_tag(gen, tag)
@@ -107,6 +108,7 @@ class EmulatorWrapper:
                 port=port,
                 headless=headless,
                 auto_interact=auto_interact,
+                main_args=main_args,
             )
         else:
             raise ValueError(