CI: Split out file format test as a separate GitHub workflow

Split out checking of file format as a separate GitHub workflow, rather
than running it as part of the project tests for every platform and
toolchain combination in CI, so that this test is not effected by the
changed paths constraints which are applied to the project tests.

.github/workflows/file_format.yml

@@ -0,0 +1,13 @@
+name: File format check
+
+on: [push, pull_request]
+
+jobs:
+  format:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-python@v2
+      with:
+        python-version: '3.x'
+    - run: python3 ./run_format_tests.py

run_format_tests.py

@@ -0,0 +1,82 @@
+#!/usr/bin/env python3
+
+# Copyright 2012-2019 The Meson development team
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+#     http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# some simple checks on the file format of:
+# - python code
+# - code samples in tests
+# - markdown documentation
+#
+# checks are:
+# - no use of tabs
+# - no use of DOS line endings
+
+import os
+import re
+from pathlib import Path
+
+def check_file(file: Path) -> None:
+    lines = file.read_bytes().split(b'\n')
+    tabdetector = re.compile(br' *\t')
+    for i, line in enumerate(lines):
+        if re.match(tabdetector, line):
+            raise SystemExit("File {} contains a tab indent on line {:d}. Only spaces are permitted.".format(file, i + 1))
+        if line.endswith(b'\r'):
+            raise SystemExit("File {} contains DOS line ending on line {:d}. Only unix-style line endings are permitted.".format(file, i + 1))
+
+def check_format() -> None:
+    check_suffixes = {'.c',
+                      '.cpp',
+                      '.cxx',
+                      '.cc',
+                      '.rs',
+                      '.f90',
+                      '.vala',
+                      '.d',
+                      '.s',
+                      '.m',
+                      '.mm',
+                      '.asm',
+                      '.java',
+                      '.txt',
+                      '.py',
+                      '.swift',
+                      '.build',
+                      '.md',
+                      }
+    skip_dirs = {
+        '.dub',                         # external deps are here
+        '.pytest_cache',
+        'meson-logs', 'meson-private',
+        'work area',
+        '.eggs', '_cache',              # e.g. .mypy_cache
+        'venv',                         # virtualenvs have DOS line endings
+    }
+    for (root, _, filenames) in os.walk('.'):
+        if any([x in root for x in skip_dirs]):
+            continue
+        for fname in filenames:
+            file = Path(fname)
+            if file.suffix.lower() in check_suffixes:
+                if file.name in ('sitemap.txt', 'meson-test-run.txt'):
+                    continue
+                check_file(root / file)
+
+
+if __name__ == '__main__':
+    script_dir = os.path.split(__file__)[0]
+    if script_dir != '':
+        os.chdir(script_dir)
+    check_format()

run_project_tests.py

@@ -1330,53 +1330,6 @@ def _run_tests(all_tests: T.List[T.Tuple[str, T.List[TestDef], bool]],
     ET.ElementTree(element=junit_root).write(xmlname, xml_declaration=True, encoding='UTF-8')
     return passing_tests, failing_tests, skipped_tests
 
-def check_file(file: Path) -> None:
-    lines = file.read_bytes().split(b'\n')
-    tabdetector = re.compile(br' *\t')
-    for i, line in enumerate(lines):
-        if re.match(tabdetector, line):
-            raise SystemExit("File {} contains a tab indent on line {:d}. Only spaces are permitted.".format(file, i + 1))
-        if line.endswith(b'\r'):
-            raise SystemExit("File {} contains DOS line ending on line {:d}. Only unix-style line endings are permitted.".format(file, i + 1))
-
-def check_format() -> None:
-    check_suffixes = {'.c',
-                      '.cpp',
-                      '.cxx',
-                      '.cc',
-                      '.rs',
-                      '.f90',
-                      '.vala',
-                      '.d',
-                      '.s',
-                      '.m',
-                      '.mm',
-                      '.asm',
-                      '.java',
-                      '.txt',
-                      '.py',
-                      '.swift',
-                      '.build',
-                      '.md',
-                      }
-    skip_dirs = {
-        '.dub',                         # external deps are here
-        '.pytest_cache',
-        'meson-logs', 'meson-private',
-        'work area',
-        '.eggs', '_cache',              # e.g. .mypy_cache
-        'venv',                         # virtualenvs have DOS line endings
-    }
-    for (root, _, filenames) in os.walk('.'):
-        if any([x in root for x in skip_dirs]):
-            continue
-        for fname in filenames:
-            file = Path(fname)
-            if file.suffix.lower() in check_suffixes:
-                if file.name in ('sitemap.txt', 'meson-test-run.txt'):
-                    continue
-                check_file(root / file)
-
 def check_meson_commands_work(use_tmpdir: bool, extra_args: T.List[str]) -> None:
     global backend, compile_commands, test_commands, install_commands
     testdir = PurePath('test cases', 'common', '1 trivial').as_posix()
@@ -1567,7 +1520,6 @@ if __name__ == '__main__':
     script_dir = os.path.split(__file__)[0]
     if script_dir != '':
         os.chdir(script_dir)
-    check_format()
     check_meson_commands_work(options.use_tmpdir, options.extra_args)
     only = collections.defaultdict(list)
     for i in options.only: