fix: #775 node_modules not ignored on Windows (#802)

src/utils/path/is-inside-another-path.ts

@@ -0,0 +1,21 @@
+import { relative, isAbsolute } from 'path';
+
+function isInsideAnotherPath(parent: string, directory: string): boolean {
+  const relativePart = relative(parent, directory);
+  // Tested folder is above parent.
+  if (relativePart.startsWith('..')) {
+    return false;
+  }
+  // Tested folder is the same as parent.
+  if (relativePart.length === 0) {
+    return false;
+  }
+  // Tested directory has nothing in common with parent.
+  if (isAbsolute(relativePart)) {
+    return false;
+  }
+  // Last option, must be subfolder.
+  return true;
+}
+
+export { isInsideAnotherPath };

src/watch/inclusive-node-watch-file-system.ts

@@ -1,4 +1,4 @@
-import { extname } from 'path';
+import { extname, relative, isAbsolute } from 'path';
 
 import type { FSWatcher } from 'chokidar';
 import chokidar from 'chokidar';
@@ -8,6 +8,7 @@ import type { Compiler } from 'webpack';
 import { clearFilesChange, updateFilesChange } from '../files-change';
 import { getInfrastructureLogger } from '../infrastructure-logger';
 import type { ForkTsCheckerWebpackPluginState } from '../plugin-state';
+import { isInsideAnotherPath } from '../utils/path/is-inside-another-path';
 
 import type { WatchFileSystem } from './watch-file-system';
 
@@ -30,7 +31,7 @@ function createIsIgnored(
     }
   });
   ignoredFunctions.push((path: string) =>
-    excluded.some((excludedPath) => path.startsWith(excludedPath))
+    excluded.some((excludedPath) => isInsideAnotherPath(excludedPath, path))
   );
   ignoredFunctions.push((path: string) =>
     BUILTIN_IGNORED_DIRS.some(

test/unit/utils/path/is-inside-another-path-unix.spec.ts

@@ -0,0 +1,25 @@
+import { isInsideAnotherPath } from '../../../../src/utils/path/is-inside-another-path';
+
+jest.mock('path', () => jest.requireActual('path').posix);
+
+const unixTests: [string, string, boolean][] = [
+  // Identical
+  ['/foo', '/foo', false],
+  // Nothing in common
+  ['/foo', '/bar', false],
+  // subfolder
+  ['/foo', '/foo/bar', true],
+  // parallel
+  ['/foo', '/foo/../bar', false],
+  // relative subfolder
+  ['/foo', '/foo/./bar', true],
+];
+
+describe('Properly detects ignored sub-folders on Unix', () => {
+  it('should work on Unix', () => {
+    unixTests.forEach(([parent, testedPath, expectedResult]) => {
+      const result = isInsideAnotherPath(parent, testedPath);
+      expect(result).toEqual(expectedResult);
+    });
+  });
+});

test/unit/utils/path/is-inside-another-path-windows.spec.ts

@@ -0,0 +1,21 @@
+import { isInsideAnotherPath } from '../../../../src/utils/path/is-inside-another-path';
+
+jest.mock('path', () => jest.requireActual('path').win32);
+
+const windowsTests: [string, string, boolean][] = [
+  // subfolder
+  ['C:\\Foo', 'C:\\Foo\\Bar', true],
+  // Nothing in common
+  ['C:\\Foo', 'C:\\Bar', false],
+  // Wrong drive.
+  ['C:\\Foo', 'D:\\Foo\\Bar', false],
+];
+
+describe('Properly detects ignored sub-folders on Windows', () => {
+  it('should work on Windows', () => {
+    windowsTests.forEach(([parent, testedPath, expectedResult]) => {
+      const result = isInsideAnotherPath(parent, testedPath);
+      expect(result).toEqual(expectedResult);
+    });
+  });
+});