pakjoy: Use proper logic to discover resources dir

qutebrowser/misc/pakjoy.py

@@ -31,7 +31,7 @@ import pathlib
 import dataclasses
 from typing import ClassVar, IO, Optional, Dict, Tuple
 
-from qutebrowser.misc import binparsing
+from qutebrowser.misc import binparsing, objects
 from qutebrowser.utils import qtutils, standarddir, version, utils, log
 
 HANGOUTS_MARKER = b"// Extension ID: nkeimhogjdpnpccoofpliimaahmaaome"
@@ -146,17 +146,43 @@ class PakParser:
         raise binparsing.ParseError("Couldn't find hangouts manifest")
 
 
-def copy_webengine_resources() -> Optional[pathlib.Path]:
-    """Copy qtwebengine resources to local dir for patching."""
-    resources_dir = qtutils.library_path(qtutils.LibraryPath.data)
+def _find_webengine_resources() -> pathlib.Path:
+    """Find the QtWebEngine resources dir.
+
+    Mirrors logic from QtWebEngine:
+    https://github.com/qt/qtwebengine/blob/v6.6.0/src/core/web_engine_library_info.cpp#L293-L341
+    """
+    if RESOURCES_ENV_VAR in os.environ:
+        return pathlib.Path(os.environ[RESOURCES_ENV_VAR])
+
+    candidates = []
+    qt_data_path = qtutils.library_path(qtutils.LibraryPath.data)
     if utils.is_mac:  # pragma: no cover
         # I'm not sure how to arrive at this path without hardcoding it
         # ourselves. importlib_resources("PyQt6.Qt6") can serve as a
         # replacement for the qtutils bit but it doesn't seem to help find the
-        # actually Resources folder.
-        resources_dir /= pathlib.Path("lib", "QtWebEngineCore.framework", "Resources")
-    else:
-        resources_dir /= "resources"
+        # actuall Resources folder.
+        candidates.append(
+            qt_data_path / "lib" / "QtWebEngineCore.framework" / "Resources"
+        )
+
+    candidates += [
+        qt_data_path / "resources",
+        qt_data_path,
+        pathlib.Path(objects.qapp.applicationDirPath()),
+        pathlib.Path.home() / f".{objects.qapp.applicationName()}",
+    ]
+
+    for candidate in candidates:
+        if (candidate / PAK_FILENAME).exists():
+            return candidate
+
+    raise binparsing.ParseError("Couldn't find webengine resources dir")
+
+
+def copy_webengine_resources() -> Optional[pathlib.Path]:
+    """Copy qtwebengine resources to local dir for patching."""
+    resources_dir = _find_webengine_resources()
     work_dir = pathlib.Path(standarddir.cache()) / CACHE_DIR_NAME
 
     if work_dir.exists():

tests/unit/misc/test_pakjoy.py

@@ -36,10 +36,9 @@ skip_if_unsupported = pytest.mark.skipif(
 
 
 @pytest.fixture(autouse=True)
-def clean_env():
-    yield
-    if pakjoy.RESOURCES_ENV_VAR in os.environ:
-        del os.environ[pakjoy.RESOURCES_ENV_VAR]
+def prepare_env(qapp, monkeypatch):
+    monkeypatch.setattr(pakjoy.objects, "qapp", qapp)
+    monkeypatch.delenv(pakjoy.RESOURCES_ENV_VAR, raising=False)
 
 
 def patch_version(monkeypatch, *args):
@@ -78,6 +77,86 @@ def test_version_gate(cache_tmpdir, unaffected_version, mocker, workdir_exists):
     assert not workdir.exists()
 
 
+class TestFindWebengineResources:
+    @pytest.fixture
+    def qt_data_path(self, monkeypatch: pytest.MonkeyPatch, tmp_path: pathlib.Path):
+        """Patch qtutils.library_path() to return a temp dir."""
+        qt_data_path = tmp_path / "qt_data"
+        qt_data_path.mkdir()
+        monkeypatch.setattr(pakjoy.qtutils, "library_path", lambda _which: qt_data_path)
+        return qt_data_path
+
+    @pytest.fixture
+    def application_dir_path(
+        self,
+        monkeypatch: pytest.MonkeyPatch,
+        tmp_path: pathlib.Path,
+        qt_data_path: pathlib.Path,  # needs patching
+    ):
+        """Patch QApplication.applicationDirPath() to return a temp dir."""
+        app_dir_path = tmp_path / "app_dir"
+        app_dir_path.mkdir()
+        monkeypatch.setattr(
+            pakjoy.objects.qapp, "applicationDirPath", lambda: app_dir_path
+        )
+        return app_dir_path
+
+    @pytest.fixture
+    def fallback_path(
+        self,
+        monkeypatch: pytest.MonkeyPatch,
+        tmp_path: pathlib.Path,
+        qt_data_path: pathlib.Path,  # needs patching
+        application_dir_path: pathlib.Path,  # needs patching
+    ):
+        """Patch the fallback path to return a temp dir."""
+        home_path = tmp_path / "home"
+        monkeypatch.setattr(pakjoy.pathlib.Path, "home", lambda: home_path)
+
+        app_path = home_path / f".{pakjoy.objects.qapp.applicationName()}"
+        app_path.mkdir(parents=True)
+        return app_path
+
+    @pytest.mark.parametrize("create_file", [True, False])
+    def test_overridden(
+        self, monkeypatch: pytest.MonkeyPatch, tmp_path: pathlib.Path, create_file: bool
+    ):
+        """Test the overridden path is used."""
+        override_path = tmp_path / "override"
+        override_path.mkdir()
+        monkeypatch.setenv(pakjoy.RESOURCES_ENV_VAR, str(override_path))
+        if create_file:  # should get this no matter if file exists or not
+            (override_path / pakjoy.PAK_FILENAME).touch()
+        assert pakjoy._find_webengine_resources() == override_path
+
+    @pytest.mark.parametrize("with_subfolder", [True, False])
+    def test_qt_data_path(self, qt_data_path: pathlib.Path, with_subfolder: bool):
+        """Test qtutils.library_path() is used."""
+        resources_path = qt_data_path
+        if with_subfolder:
+            resources_path /= "resources"
+            resources_path.mkdir()
+        (resources_path / pakjoy.PAK_FILENAME).touch()
+        assert pakjoy._find_webengine_resources() == resources_path
+
+    def test_application_dir_path(self, application_dir_path: pathlib.Path):
+        """Test QApplication.applicationDirPath() is used."""
+        (application_dir_path / pakjoy.PAK_FILENAME).touch()
+        assert pakjoy._find_webengine_resources() == application_dir_path
+
+    def test_fallback_path(self, fallback_path: pathlib.Path):
+        """Test fallback path is used."""
+        (fallback_path / pakjoy.PAK_FILENAME).touch()
+        assert pakjoy._find_webengine_resources() == fallback_path
+
+    def test_nowhere(self, fallback_path: pathlib.Path):
+        """Test we raise if we can't find the resources."""
+        with pytest.raises(
+            binparsing.ParseError, match="Couldn't find webengine resources dir"
+        ):
+            pakjoy._find_webengine_resources()
+
+
 def json_without_comments(bytestring):
     str_without_comments = "\n".join(
         [
@@ -131,6 +210,9 @@ class TestWithRealResourcesFile:
         tmpfile = work_dir / "tmp.txt"
         tmpfile.touch()
 
+        # Set by first call to copy_webengine_resources()
+        del os.environ[pakjoy.RESOURCES_ENV_VAR]
+
         pakjoy.copy_webengine_resources()
         assert not tmpfile.exists()