Improve output for missing config keys (#7572)

Co-authored-by: Bruno Oliveira <nicoddemus@gmail.com>

changelog/7572.improvement.rst

@@ -1 +1 @@
-When a plugin listed in ``required_plugins`` is missing, a simple error message is now shown instead of a stacktrace.
+When a plugin listed in ``required_plugins`` is missing or an unknown config key is used with ``--strict-config``, a simple error message is now shown instead of a stacktrace.

src/_pytest/config/__init__.py

@@ -1252,7 +1252,7 @@ class Config:
 
     def _warn_or_fail_if_strict(self, message: str) -> None:
         if self.known_args_namespace.strict_config:
-            fail(message, pytrace=False)
+            raise UsageError(message)
 
         self.issue_config_time_warning(PytestConfigWarning(message), stacklevel=3)
 

testing/test_config.py

@@ -181,7 +181,7 @@ class TestParseIni:
     @pytest.mark.parametrize(
         "ini_file_text, invalid_keys, warning_output, exception_text",
         [
-            (
+            pytest.param(
                 """
                 [pytest]
                 unknown_ini = value1
@@ -194,8 +194,9 @@ class TestParseIni:
                     "*PytestConfigWarning:*Unknown config option: unknown_ini",
                 ],
                 "Unknown config option: another_unknown_ini",
+                id="2-unknowns",
             ),
-            (
+            pytest.param(
                 """
                 [pytest]
                 unknown_ini = value1
@@ -207,8 +208,9 @@ class TestParseIni:
                     "*PytestConfigWarning:*Unknown config option: unknown_ini",
                 ],
                 "Unknown config option: unknown_ini",
+                id="1-unknown",
             ),
-            (
+            pytest.param(
                 """
                 [some_other_header]
                 unknown_ini = value1
@@ -218,8 +220,9 @@ class TestParseIni:
                 [],
                 [],
                 "",
+                id="unknown-in-other-header",
             ),
-            (
+            pytest.param(
                 """
                 [pytest]
                 minversion = 5.0.0
@@ -227,8 +230,9 @@ class TestParseIni:
                 [],
                 [],
                 "",
+                id="no-unknowns",
             ),
-            (
+            pytest.param(
                 """
                 [pytest]
                 conftest_ini_key = 1
@@ -236,6 +240,7 @@ class TestParseIni:
                 [],
                 [],
                 "",
+                id="1-known",
             ),
         ],
     )
@@ -249,7 +254,8 @@ class TestParseIni:
                 parser.addini("conftest_ini_key", "")
             """
         )
-        testdir.tmpdir.join("pytest.ini").write(textwrap.dedent(ini_file_text))
+        testdir.makepyfile("def test(): pass")
+        testdir.makeini(ini_file_text)
 
         config = testdir.parseconfig()
         assert sorted(config._get_unknown_ini_keys()) == sorted(invalid_keys)
@@ -257,9 +263,13 @@ class TestParseIni:
         result = testdir.runpytest()
         result.stdout.fnmatch_lines(warning_output)
 
-        if exception_text:
         result = testdir.runpytest("--strict-config")
-            result.stdout.fnmatch_lines("INTERNALERROR>*" + exception_text)
+        if exception_text:
+            result.stderr.fnmatch_lines("ERROR: " + exception_text)
+            assert result.ret == pytest.ExitCode.USAGE_ERROR
+        else:
+            result.stderr.no_fnmatch_line(exception_text)
+            assert result.ret == pytest.ExitCode.OK
 
     @pytest.mark.filterwarnings("default")
     def test_silence_unknown_key_warning(self, testdir: Testdir) -> None: