Ignore mypy lint errors for other files

news/2 Fixes/10190.md

@@ -0,0 +1,2 @@
+Prevent mypy errors for other files showing in current file.
+(thanks [Steve Dignam](https://github.com/sbdchd))

src/client/linters/mypy.ts

@@ -1,11 +1,14 @@
 import { CancellationToken, OutputChannel, TextDocument } from 'vscode';
 import '../common/extensions';
+import { escapeRegExp } from 'lodash';
 import { Product } from '../common/types';
 import { IServiceContainer } from '../ioc/types';
 import { BaseLinter } from './baseLinter';
 import { ILintMessage } from './types';
 
-export const REGEX = '(?<file>[^:]+):(?<line>\\d+)(:(?<column>\\d+))?: (?<type>\\w+): (?<message>.*)\\r?(\\n|$)';
+export function getRegex(filepath: string): string {
+    return `${escapeRegExp(filepath)}:(?<line>\\d+)(:(?<column>\\d+))?: (?<type>\\w+): (?<message>.*)\\r?(\\n|$)`;
+}
 const COLUMN_OFF_SET = 1;
 
 export class MyPy extends BaseLinter {
@@ -14,7 +17,9 @@ export class MyPy extends BaseLinter {
     }
 
     protected async runLinter(document: TextDocument, cancellation: CancellationToken): Promise<ILintMessage[]> {
-        const messages = await this.run([document.uri.fsPath], document, cancellation, REGEX);
+        const relativeFilePath = document.uri.fsPath.slice(this.getWorkspaceRootPath(document).length + 1);
+        const regex = getRegex(relativeFilePath);
+        const messages = await this.run([document.uri.fsPath], document, cancellation, regex);
         messages.forEach((msg) => {
             msg.severity = this.parseMessagesSeverity(msg.type, this.pythonSettings.linting.mypyCategorySeverity);
             msg.code = msg.type;

src/test/linters/mypy.unit.test.ts

@@ -5,7 +5,7 @@
 
 import { expect } from 'chai';
 import { parseLine } from '../../client/linters/baseLinter';
-import { REGEX } from '../../client/linters/mypy';
+import { getRegex } from '../../client/linters/mypy';
 import { ILintMessage, LinterId } from '../../client/linters/types';
 
 // This following is a real-world example. See gh=2380.
@@ -55,9 +55,45 @@ suite('Linting - MyPy', () => {
             ],
         ];
         for (const [line, expected] of tests) {
-            const msg = parseLine(line, REGEX, LinterId.MyPy, 1);
+            const msg = parseLine(line, getRegex('provider.pyi'), LinterId.MyPy, 1);
 
             expect(msg).to.deep.equal(expected);
         }
     });
+    test('regex excludes unexpected files', () => {
+        // mypy run against `foo/bar.py` returning errors for foo/__init__.py
+        const outputWithUnexpectedFile = `\
+foo/__init__.py:4:5: error: Statement is unreachable  [unreachable]
+foo/bar.py:2:14: error: Incompatible types in assignment (expression has type "str", variable has type "int")  [assignment]
+Found 2 errors in 2 files (checked 1 source file)
+`;
+
+        const lines = outputWithUnexpectedFile.split('\n');
+        const tests: [string, ILintMessage | undefined][] = [
+            [lines[0], undefined],
+            [
+                lines[1],
+                {
+                    code: undefined,
+                    message:
+                        'Incompatible types in assignment (expression has type "str", variable has type "int")  [assignment]',
+                    column: 13,
+                    line: 2,
+                    type: 'error',
+                    provider: 'mypy',
+                },
+            ],
+            [lines[2], undefined],
+        ];
+        for (const [line, expected] of tests) {
+            const msg = parseLine(line, getRegex('foo/bar.py'), LinterId.MyPy, 1);
+
+            expect(msg).to.deep.equal(expected);
+        }
+    });
+    test('getRegex escapes filename correctly', () => {
+        expect(getRegex('foo/bar.py')).to.eql(
+            String.raw`foo/bar\.py:(?<line>\d+)(:(?<column>\d+))?: (?<type>\w+): (?<message>.*)\r?(\n|$)`,
+        );
+    });
 });