Replace colons in transform cache filenames

CHANGELOG.md

@@ -24,6 +24,7 @@
 - `[jest-snapshot]` Handle arrays when merging snapshots ([#7089](https://github.com/facebook/jest/pull/7089))
 - `[expect]` Extract names of async and generator functions ([#8362](https://github.com/facebook/jest/pull/8362))
 - `[jest-runtime]` Fix virtual mocks not being unmockable after previously being mocked ([#8396](https://github.com/facebook/jest/pull/8396))
+- `[jest-transform]` Replace special characters in transform cache filenames to support Windows ([#8353](https://github.com/facebook/jest/pull/8353))
 
 ### Chore & Maintenance
 

packages/jest-transform/src/ScriptTransformer.ts

@@ -102,6 +102,7 @@ export default class ScriptTransformer {
         .update(fileData)
         .update(configString)
         .update(instrument ? 'instrument' : '')
+        .update(filename)
         .update(CACHE_VERSION)
         .digest('hex');
     }
@@ -121,11 +122,11 @@ export default class ScriptTransformer {
     // Create sub folders based on the cacheKey to avoid creating one
     // directory with many files.
     const cacheDir = path.join(baseCacheDir, cacheKey[0] + cacheKey[1]);
+    const cacheFilenamePrefix = path
+      .basename(filename, path.extname(filename))
+      .replace(/\W/g, '');
     const cachePath = slash(
-      path.join(
-        cacheDir,
-        path.basename(filename, path.extname(filename)) + '_' + cacheKey,
-      ),
+      path.join(cacheDir, cacheFilenamePrefix + '_' + cacheKey),
     );
     createDirectory(cacheDir);
 

packages/jest-transform/src/__tests__/script_transformer.test.js

@@ -152,6 +152,7 @@ describe('ScriptTransformer', () => {
 
     mockFs = object({
       '/fruits/banana.js': ['module.exports = "banana";'].join('\n'),
+      '/fruits/banana:colon.js': ['module.exports = "bananaColon";'].join('\n'),
       '/fruits/grapefruit.js': [
         'module.exports = function () { return "grapefruit"; }',
       ].join('\n'),
@@ -532,6 +533,34 @@ describe('ScriptTransformer', () => {
     expect(writeFileAtomic.sync).toBeCalled();
   });
 
+  it('reads values from the cache when the file contains colons', () => {
+    const transformConfig = {
+      ...config,
+      transform: [['^.+\\.js$', 'test_preprocessor']],
+    };
+    let scriptTransformer = new ScriptTransformer(transformConfig);
+    scriptTransformer.transform('/fruits/banana:colon.js', {});
+
+    const cachePath = getCachePath(mockFs, config);
+    expect(writeFileAtomic.sync).toBeCalled();
+    expect(writeFileAtomic.sync.mock.calls[0][0]).toBe(cachePath);
+
+    // Cache the state in `mockFsCopy`
+    const mockFsCopy = mockFs;
+    jest.resetModuleRegistry();
+    reset();
+
+    // Restore the cached fs
+    mockFs = mockFsCopy;
+    scriptTransformer = new ScriptTransformer(transformConfig);
+    scriptTransformer.transform('/fruits/banana:colon.js', {});
+
+    expect(fs.readFileSync).toHaveBeenCalledTimes(2);
+    expect(fs.readFileSync).toBeCalledWith('/fruits/banana:colon.js', 'utf8');
+    expect(fs.readFileSync).toBeCalledWith(cachePath, 'utf8');
+    expect(writeFileAtomic.sync).not.toBeCalled();
+  });
+
   it('does not reuse the in-memory cache between different projects', () => {
     const scriptTransformer = new ScriptTransformer({
       ...config,