chore: optimise unit tests (#2293)

* optimise unit tests - Cache loading the config TOML

Unit test time: 13.1s -> 10.5s

* optimise unit tests - use the same pyproject validator across the tests

Unit test time: 10.5s -> 5.7s

* optimise unit tests - selector optimisation

Unit test time: 5.7s -> 5.1s

* optimise unit tests - build options computation cache

Unit test time: 5.1s -> 3.2s

* Use functools.cache rather than functools.lru_cache

* Don't overwrite build_options when applying functools.cache

cibuildwheel/options.py

@@ -591,6 +591,10 @@ class Options:
         except FileNotFoundError:
             self.pyproject_toml = None
 
+        # cache the build options method so repeated calls don't need to
+        # resolve the options again
+        self.build_options = functools.cache(self._compute_build_options)
+
     @functools.cached_property
     def config_file_path(self) -> Path | None:
         args = self.command_line_arguments
@@ -667,9 +671,11 @@ class Options:
             allow_empty=allow_empty,
         )
 
-    def build_options(self, identifier: str | None) -> BuildOptions:
+    def _compute_build_options(self, identifier: str | None) -> BuildOptions:
         """
-        Compute BuildOptions for a single run configuration.
+        Compute BuildOptions for a single run configuration. Normally accessed
+        through the `build_options` method, which is the same but the result
+        is cached.
         """
 
         with self.reader.identifier(identifier):

cibuildwheel/selector.py

@@ -1,7 +1,7 @@
-import fnmatch
 import itertools
 from dataclasses import dataclass
 from enum import Enum
+from fnmatch import fnmatch
 from typing import Any
 
 import bracex
@@ -18,9 +18,10 @@ def selector_matches(patterns: str, string: str) -> bool:
     expansion. For example, 'cp{36,37}-*' would match either of 'cp36-*' or
     'cp37-*'.
     """
+
     patterns_list = patterns.split()
     expanded_patterns = itertools.chain.from_iterable(bracex.expand(p) for p in patterns_list)
-    return any(fnmatch.fnmatch(string, pat) for pat in expanded_patterns)
+    return any(fnmatch(string, pat) for pat in expanded_patterns)
 
 
 class EnableGroup(Enum):
@@ -59,15 +60,11 @@ class BuildSelector:
                 return False
 
         # filter out groups that are not enabled
-        if EnableGroup.CPythonFreeThreading not in self.enable and selector_matches(
-            "cp3??t-*", build_id
-        ):
+        if EnableGroup.CPythonFreeThreading not in self.enable and fnmatch(build_id, "cp3??t-*"):
             return False
-        if EnableGroup.CPythonPrerelease not in self.enable and selector_matches(
-            "cp314*", build_id
-        ):
+        if EnableGroup.CPythonPrerelease not in self.enable and fnmatch(build_id, "cp314*"):
             return False
-        if EnableGroup.PyPy not in self.enable and selector_matches("pp*", build_id):
+        if EnableGroup.PyPy not in self.enable and fnmatch(build_id, "pp*"):
             return False
 
         should_build = selector_matches(self.build_config, build_id)

cibuildwheel/util/resources.py

@@ -1,3 +1,4 @@
+import functools
 import tomllib
 from pathlib import Path
 from typing import Final
@@ -16,6 +17,8 @@ VIRTUALENV: Final[Path] = PATH / "virtualenv.toml"
 CIBUILDWHEEL_SCHEMA: Final[Path] = PATH / "cibuildwheel.schema.json"
 
 
+# this value is cached because it's used a lot in unit tests
+@functools.cache
 def read_python_configs(config: PlatformName) -> list[dict[str, str]]:
     with BUILD_PLATFORMS.open("rb") as f:
         loaded_file = tomllib.load(f)

unit_test/validate_schema_test.py

@@ -10,15 +10,22 @@ from cibuildwheel.util import resources
 DIR = Path(__file__).parent.resolve()
 
 
-def test_validate_default_schema():
+@pytest.fixture(scope="session")
+def validator() -> validate_pyproject.api.Validator:
+    """
+    Reuse the validator for all tests, to keep unit tests fast.
+    """
+    return validate_pyproject.api.Validator()
+
+
+def test_validate_default_schema(validator: validate_pyproject.api.Validator) -> None:
     with resources.DEFAULTS.open("rb") as f:
         example = tomllib.load(f)
 
-    validator = validate_pyproject.api.Validator()
     assert validator(example) is not None
 
 
-def test_validate_container_engine():
+def test_validate_container_engine(validator: validate_pyproject.api.Validator) -> None:
     """
     This test checks container engine can be overridden - it used to be a
     global option but is now a build option.
@@ -38,12 +45,13 @@ def test_validate_container_engine():
         """
     )
 
-    validator = validate_pyproject.api.Validator()
     assert validator(example) is not None
 
 
 @pytest.mark.parametrize("platform", ["macos", "windows"])
-def test_validate_bad_container_engine(platform: str) -> None:
+def test_validate_bad_container_engine(
+    validator: validate_pyproject.api.Validator, platform: str
+) -> None:
     """
     container-engine is not a valid option for macos or windows
     """
@@ -54,12 +62,11 @@ def test_validate_bad_container_engine(platform: str) -> None:
         """
     )
 
-    validator = validate_pyproject.api.Validator()
     with pytest.raises(validate_pyproject.error_reporting.ValidationError):
         validator(example)
 
 
-def test_overrides_select():
+def test_overrides_select(validator: validate_pyproject.api.Validator) -> None:
     example = tomllib.loads(
         """
         [[tool.cibuildwheel.overrides]]
@@ -68,11 +75,10 @@ def test_overrides_select():
         """
     )
 
-    validator = validate_pyproject.api.Validator()
     assert validator(example) is not None
 
 
-def test_overrides_no_select():
+def test_overrides_no_select(validator: validate_pyproject.api.Validator) -> None:
     example = tomllib.loads(
         """
         [[tool.cibuildwheel.overrides]]
@@ -80,12 +86,11 @@ def test_overrides_no_select():
         """
     )
 
-    validator = validate_pyproject.api.Validator()
     with pytest.raises(validate_pyproject.error_reporting.ValidationError):
         validator(example)
 
 
-def test_overrides_only_select():
+def test_overrides_only_select(validator: validate_pyproject.api.Validator) -> None:
     example = tomllib.loads(
         """
         [[tool.cibuildwheel.overrides]]
@@ -93,12 +98,11 @@ def test_overrides_only_select():
         """
     )
 
-    validator = validate_pyproject.api.Validator()
     with pytest.raises(validate_pyproject.error_reporting.ValidationError):
         validator(example)
 
 
-def test_overrides_valid_inherit():
+def test_overrides_valid_inherit(validator: validate_pyproject.api.Validator) -> None:
     example = tomllib.loads(
         """
         [[tool.cibuildwheel.overrides]]
@@ -108,11 +112,10 @@ def test_overrides_valid_inherit():
         """
     )
 
-    validator = validate_pyproject.api.Validator()
     assert validator(example) is not None
 
 
-def test_overrides_invalid_inherit():
+def test_overrides_invalid_inherit(validator: validate_pyproject.api.Validator) -> None:
     example = tomllib.loads(
         """
         [[tool.cibuildwheel.overrides]]
@@ -122,12 +125,11 @@ def test_overrides_invalid_inherit():
         """
     )
 
-    validator = validate_pyproject.api.Validator()
     with pytest.raises(validate_pyproject.error_reporting.ValidationError):
         validator(example)
 
 
-def test_overrides_invalid_inherit_value():
+def test_overrides_invalid_inherit_value(validator: validate_pyproject.api.Validator) -> None:
     example = tomllib.loads(
         """
         [[tool.cibuildwheel.overrides]]
@@ -137,12 +139,11 @@ def test_overrides_invalid_inherit_value():
         """
     )
 
-    validator = validate_pyproject.api.Validator()
     with pytest.raises(validate_pyproject.error_reporting.ValidationError):
         validator(example)
 
 
-def test_docs_examples():
+def test_docs_examples(validator: validate_pyproject.api.Validator) -> None:
     """
     Parse out all the configuration examples, build valid TOML out of them, and
     make sure they pass.
@@ -182,5 +183,5 @@ def test_docs_examples():
         print(example_txt)
         print()
         example = tomllib.loads(example_txt)
-        validator = validate_pyproject.api.Validator()
+
         assert validator(example) is not None