Bump Ruff to 0.12.9, update output parsing for new rendering

pyproject.toml

@@ -33,7 +33,7 @@ classifiers = [
     "Topic :: Software Development :: Libraries :: Python Modules",
 ]
 requires-python = ">=3.10"
-dependencies = ["pytest>=7", "black>=23", "ruff>=0.5.0"]
+dependencies = ["pytest>=7", "black>=23", "ruff>=0.12.9"]
 
 [project.entry-points.pytest11]
 examples = "pytest_examples"

pytest_examples/lint.py

@@ -56,10 +56,12 @@ def ruff_check(
     if p.returncode == 1 and stdout:
 
         def replace_offset(m: re.Match[str]):
-            line_number = int(m.group(1))
-            return f'{example.path}:{line_number + example.start_line}'
+            line_number = int(m.group(2))
+            return f'{m.group(1)}--> {example.path}:{line_number + example.start_line}'
 
-        output = re.sub(r'^-:(\d+)', replace_offset, stdout, flags=re.M)
+        # ruff >=0.12.9 renders the location on a separate ` --> file:line:col` line, indented to
+        # align with the source gutter, so the leading whitespace widens for multi-digit line numbers.
+        output = re.sub(r'^( *)--> -:(\d+)', replace_offset, stdout, flags=re.M)
         raise FormatError(f'ruff failed:\n{indent(output, "  ")}')
     elif p.returncode != 0:
         raise RuntimeError(f'Error running ruff, return code {p.returncode}:\n{stderr or stdout}')

tests/test_lint.py

@@ -24,11 +24,24 @@ def test_ruff_config():
 def test_ruff_offset():
     code = 'print(x)\n'
     example = CodeExample.create(code)
-    with pytest.raises(FormatError, match='testing.md:1:7: F821 Undefined name'):
+    with pytest.raises(FormatError, match=r'F821 Undefined name `x`\n +--> testing.md:1:7'):
         ruff_check(example, ExamplesConfig())
 
     example = CodeExample.create(code, start_line=10)
-    with pytest.raises(FormatError, match='testing.md:11:7: F821 Undefined name'):
+    with pytest.raises(FormatError, match=r'F821 Undefined name `x`\n +--> testing.md:11:7'):
+        ruff_check(example, ExamplesConfig())
+
+
+def test_ruff_offset_multiline():
+    # the error is on line 10 of the example, so ruff widens the gutter and indents `-->` further;
+    # the offset substitution must still rewrite the `-` placeholder to the real path
+    code = 'x = 1\n' * 9 + 'print(y)\n'
+    example = CodeExample.create(code)
+    with pytest.raises(FormatError, match=r'F821 Undefined name `y`\n +--> testing.md:10:7'):
+        ruff_check(example, ExamplesConfig())
+
+    example = CodeExample.create(code, start_line=10)
+    with pytest.raises(FormatError, match=r'F821 Undefined name `y`\n +--> testing.md:20:7'):
         ruff_check(example, ExamplesConfig())
 
 

tests/test_run_examples.py

@@ -109,8 +109,8 @@ def test_find_run_examples(example: CodeExample, eval_example: EvalExample):
         '=== FAILURES ===\n',
         '___ test_find_run_examples[my_file.md:1-4] ___\n',
         'ruff failed:\n',
-        '  my_file.md:2:8: F401 [*] `sys` imported but unused\n',
-        '  my_file.md:3:7: F821 Undefined name `missing`\n',
+        '  F401 [*] `sys` imported but unused\n   --> my_file.md:2:8\n',
+        '  F821 Undefined name `missing`\n   --> my_file.md:3:7\n',
         '  Found 2 errors.\n',
         '  [*] 1 fixable with the `--fix` option.\n',
         '=== short test summary info ===\n',