mformat: detect invalid config

- detect unknown config keys in format config
- add test for detection of invalid config values
- detect invalid .editorconfig values

Fixes #13569

2 files changed, 44 insertions, 5 deletions

diff --git a/mesonbuild/mformat.py b/mesonbuild/mformat.py
index 6a28684d6..d87674bc7 100644
--- a/mesonbuild/mformat.py
+++ b/mesonbuild/mformat.py
@@ -839,7 +839,10 @@ class Formatter:
 
                 getter = f.metadata['getter']
                 for section in sections:
-                    value = getter(cp, section, f.name, fallback=None)
+                    try:
+                        value = getter(cp, section, f.name, fallback=None)
+                    except ValueError as e:
+                        raise MesonException(f'Invalid type for key "{f.name}" in "{editorconfig_file}" file:\n{e}') from e
                     if value is not None:
                         setattr(config, f.name, value)
 
@@ -858,6 +861,10 @@ class Formatter:
             except ParsingError as e:
                 raise MesonException(f'Unable to parse configuration file "{configuration_file}":\n{e}') from e
 
+            extra_keys = sorted(set(cp.defaults()).difference(f.name for f in fields(config)))
+            if extra_keys:
+                raise MesonException(f'Unknown config keys: "{", ".join(extra_keys)}" in configuration file "{configuration_file}"')
+
             for f in fields(config):
                 getter = f.metadata['getter']
                 try:
@@ -992,9 +999,8 @@ def run(options: argparse.Namespace) -> int:
 
 # TODO: remove empty newlines when more than N (2...)
 # TODO: magic comment to prevent formatting
-# TODO: handle meson.options ?
 # TODO: split long lines on binary operators
-# TODO: align series of assignements
+# TODO: align series of assignments
 # TODO: align comments
 # TODO: move comments on long lines
 
diff --git a/unittests/platformagnostictests.py b/unittests/platformagnostictests.py
index 7d6ffa0f9..3ee0b458c 100644
--- a/unittests/platformagnostictests.py
+++ b/unittests/platformagnostictests.py
@@ -15,7 +15,7 @@ from pathlib import Path
 
 from .baseplatformtests import BasePlatformTests
 from .helpers import is_ci
-from mesonbuild.mesonlib import EnvironmentVariables, ExecutableSerialisation, MesonException, is_linux, python_command
+from mesonbuild.mesonlib import EnvironmentVariables, ExecutableSerialisation, MesonException, is_linux, python_command, windows_proof_rmtree
 from mesonbuild.mformat import Formatter, match_path
 from mesonbuild.optinterpreter import OptionInterpreter, OptionException
 from mesonbuild.options import OptionStore
@@ -336,7 +336,40 @@ class PlatformAgnosticTests(BasePlatformTests):
 
         for filename, pattern, expected in cases:
             self.assertTrue(match_path(filename, pattern) is expected, f'{filename} -> {pattern}')
-    
+
+    def test_format_invalid_config_key(self) -> None:
+        fd, fname = tempfile.mkstemp(suffix='.ini', text=True)
+        self.addCleanup(os.unlink, fname)
+
+        with os.fdopen(fd, 'w', encoding='utf-8') as handle:
+            handle.write('not_an_option = 42\n')
+
+        with self.assertRaises(MesonException):
+            Formatter(Path(fname), use_editor_config=False, fetch_subdirs=False)
+
+    def test_format_invalid_config_value(self) -> None:
+        fd, fname = tempfile.mkstemp(suffix='.ini', text=True)
+        self.addCleanup(os.unlink, fname)
+
+        with os.fdopen(fd, 'w', encoding='utf-8') as handle:
+            handle.write('max_line_length = string\n')
+
+        with self.assertRaises(MesonException):
+            Formatter(Path(fname), use_editor_config=False, fetch_subdirs=False)
+
+    def test_format_invalid_editorconfig_value(self) -> None:
+        dirpath = tempfile.mkdtemp()
+        self.addCleanup(windows_proof_rmtree, dirpath)
+
+        editorconfig = Path(dirpath, '.editorconfig')
+        with open(editorconfig, 'w', encoding='utf-8') as handle:
+            handle.write('[*]\n')
+            handle.write('indent_size = string\n')
+
+        formatter = Formatter(None, use_editor_config=True, fetch_subdirs=False)
+        with self.assertRaises(MesonException):
+            formatter.load_editor_config(editorconfig)
+
     def test_format_empty_file(self) -> None:
         formatter = Formatter(None, use_editor_config=False, fetch_subdirs=False)
         for code in ('', '\n'):