fixup! build: validate build-system table schema

tests/test_projectbuilder.py

@@ -1,7 +1,6 @@
 # SPDX-License-Identifier: MIT
 
 
-import contextlib
 import copy
 import importlib
 import logging
@@ -32,11 +31,6 @@
 }
 
 
-@contextlib.contextmanager
-def nullcontext():
-    yield
-
-
 class MockDistribution(importlib_metadata.Distribution):
     def locate_file(self, path):  # pragma: no cover
         return ''
@@ -580,50 +574,53 @@ def test_log(mocker, caplog, test_flit_path):
 
 
 @pytest.mark.parametrize(
-    ['pyproject_toml', 'raises'],
+    ('pyproject_toml', 'error_message'),
     [
         (
             {'build-system': {}},
-            pytest.raises(build.BuildSystemTableValidationError, match='`requires` is a required property'),
+            '`requires` is a required property',
         ),
         (
             {'build-system': {'requires': 'not an array'}},
-            pytest.raises(build.BuildSystemTableValidationError, match='`requires` must be an array of strings'),
+            '`requires` must be an array of strings',
         ),
         (
             {'build-system': {'requires': [1]}},
-            pytest.raises(build.BuildSystemTableValidationError, match='`requires` must be an array of strings'),
+            '`requires` must be an array of strings',
         ),
         (
             {'build-system': {'requires': ['foo']}},
-            nullcontext(),
+            None,
         ),
         (
             {'build-system': {'requires': ['foo'], 'build-backend': ['not a string']}},
-            pytest.raises(build.BuildSystemTableValidationError, match='`build-backend` must be a string'),
+            '`build-backend` must be a string',
         ),
         (
             {'build-system': {'requires': ['foo'], 'build-backend': 'bar'}},
-            nullcontext(),
+            None,
         ),
         (
             {'build-system': {'requires': ['foo'], 'backend-path': 'not an array'}},
-            pytest.raises(build.BuildSystemTableValidationError, match='`backend-path` must be an array of strings'),
+            '`backend-path` must be an array of strings',
         ),
         (
             {'build-system': {'requires': ['foo'], 'backend-path': [1]}},
-            pytest.raises(build.BuildSystemTableValidationError, match='`backend-path` must be an array of strings'),
+            '`backend-path` must be an array of strings',
         ),
         (
             {'build-system': {'requires': ['foo'], 'build-backend': 'bar', 'backend-path': ['baz']}},
-            nullcontext(),
+            None,
         ),
         (
             {'build-system': {'requires': ['foo'], 'unknown-prop': False}},
-            pytest.raises(build.BuildSystemTableValidationError, match='Unknown properties: unknown-prop'),
+            'Unknown properties: unknown-prop',
         ),
     ],
 )
-def test_parse_build_system_table_type_validation(pyproject_toml, raises):
-    with raises:
+def test_parse_build_system_table_type_validation(pyproject_toml, error_message):
+    if error_message is not None:
+        with pytest.raises(build.BuildSystemTableValidationError, match=error_message):
+            build._parse_build_system_table(pyproject_toml)
+    else:
         build._parse_build_system_table(pyproject_toml)