tests: test that we always set encoding

(cherry-picked from c0a2025d03 by
Paolo Bonzini)

.github/workflows/lint_mypy.yml

@@ -23,6 +23,15 @@ jobs:
     - run: python -m pip install pylint==2.4.4
     - run: pylint mesonbuild
 
+  custom_lint:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-python@v2
+      with:
+        python-version: '3.x'
+    - run: python ./run_custom_lint.py
+
   mypy:
     runs-on: ubuntu-latest
     steps:

run_custom_lint.py

@@ -0,0 +1,76 @@
+#!/usr/bin/env python3
+
+from pathlib import Path
+import typing as T
+
+root = Path(__file__).absolute().parent
+mesonbuild = root / 'mesonbuild'
+
+whitelist = ['mesonbuild/', 'run_', 'ci/', 'tools/', 'docs/']
+
+def check_missing_encoding(lines: T.List[str], path: str) -> int:
+    errors = 0
+    functions = ['read_text', 'write_text', 'open']
+    for num, line in enumerate(lines):
+        for func in functions:
+            l = line
+
+            # Skip ignored lines
+            if '[ignore encoding]' in l:
+                continue
+
+            # Do we have a match?
+            loc = l.find(func + '(')
+            if loc < 0:
+                continue
+            if loc > 0 and ord(l[loc-1].lower()) in [*range(ord('a'), ord('z')), *range(ord('0'), ord('9')), '_']:
+                continue
+            loc += len(func) + 1
+            # Some preprocessign to make parsing easier
+            l = l[loc:]
+            l = l.replace(' ', '')
+            l = l.replace('\t', '')
+            l = l.replace('\n', '')
+            l = l.replace('\'', '"')
+
+            # Parameter begin
+            args = ''
+            b_open = 1
+            while l:
+                c = l[0]
+                l = l[1:]
+                if c == ')':
+                    b_open -= 1
+                if b_open == 0:
+                    break
+                elif b_open == 1:
+                    args += c
+                if c == '(':
+                    b_open += 1
+
+            binary_modes = ['rb', 'br', 'r+b', 'wb', 'bw', 'ab', 'ba']
+            is_binary = any([f'"{x}"' in args for x in binary_modes])
+            if 'encoding=' not in args and not (func == 'open' and is_binary):
+                location = f'\x1b[33;1m[\x1b[0;1m{path}:{num+1}\x1b[33m]\x1b[0m'
+                #print(f'{location:<64}: \x1b[31;1mERROR:\x1b[0m Missing `encoding=` parameter in "{line.strip()}"')
+                print(f'{location:<72}: \x1b[31;1mERROR:\x1b[0m Missing `encoding=` parameter in `{func}` call')
+                errors += 1
+    return errors
+
+def main() -> int:
+    print('Scanning mesonbuild...')
+    errors = 0
+    for i in sorted(root.glob('**/*.py')):
+        raw = i.read_text(encoding='utf-8')
+        lines = raw.splitlines()
+        filename = i.relative_to(root).as_posix()
+
+        if not any([filename.startswith(x) for x in whitelist]):
+            continue
+
+        errors += check_missing_encoding(lines, filename)
+    print(f'Found {errors} errors while scanning mesonbuild')
+    return 0 if errors == 0 else 1
+
+if __name__ == '__main__':
+    raise SystemExit(main())

run_mypy.py

@@ -41,7 +41,7 @@ modules = [
     'mesonbuild/optinterpreter.py',
     'mesonbuild/programs.py',
 
-    'run_encoding_tests.py',
+    'run_custom_lint.py',
     'run_mypy.py',
     'run_single_test.py',
     'tools'