fix(runtime): generates correct source maps when instrumenting

Closes jestjs#5739
huafu · Sep 30, 2018 · 70c4405 · 70c4405
1 parent 8c86fe8
commit 70c4405
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Showing 2 changed files with 53 additions and 19 deletions.
diff --git a/packages/jest-runtime/src/__tests__/script_transformer.test.js b/packages/jest-runtime/src/__tests__/script_transformer.test.js
@@ -364,6 +364,14 @@ describe('ScriptTransformer', () => {
       mappings: ';AAAA',
       version: 3,
     };
+    const expectedMap = {
+      version: 3,
+      sources: ['banana.js'],
+      names: ['content'],
+      mappings: ';;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;AAAAA',
+      file: 'banana.js',
+      sourcesContent: ['content'],
+    };
 
     require('preprocessor-with-sourcemaps').process.mockReturnValue({
       code: 'content',
@@ -374,7 +382,7 @@ describe('ScriptTransformer', () => {
       collectCoverage: true,
     });
     expect(result.sourceMapPath).toEqual(expect.any(String));
-    const mapStr = JSON.stringify(map);
+    const mapStr = JSON.stringify(expectedMap);
     expect(writeFileAtomic.sync).toBeCalledWith(result.sourceMapPath, mapStr, {
       encoding: 'utf8',
     });
@@ -388,8 +396,16 @@ describe('ScriptTransformer', () => {
 
     const sourceMap = JSON.stringify({
       mappings: 'AAAA,IAAM,CAAC,GAAW,CAAC,CAAC',
+      sources: ['banana.js'],
       version: 3,
     });
+    const expectedSourceMaps = {
+      version: 3,
+      sources: ['banana.js'],
+      names: [],
+      mappings:
+        ';;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;AAAA,IAAM,sDAAY,CAAZ,CAAN',
+    };
 
     const content =
       'var x = 1;\n' +
@@ -404,7 +420,7 @@ describe('ScriptTransformer', () => {
     expect(result.sourceMapPath).toEqual(expect.any(String));
     expect(writeFileAtomic.sync).toBeCalledWith(
       result.sourceMapPath,
-      sourceMap,
+      JSON.stringify(expectedSourceMaps),
       {encoding: 'utf8'},
     );
   });
@@ -419,6 +435,14 @@ describe('ScriptTransformer', () => {
       mappings: ';AAAA',
       version: 3,
     };
+    const expectedMap = {
+      version: 3,
+      sources: ['banana.js'],
+      names: ['content'],
+      mappings: ';;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;AAAAA',
+      file: 'banana.js',
+      sourcesContent: ['content'],
+    };
 
     require('preprocessor-with-sourcemaps').process.mockReturnValue({
       code: 'content',
@@ -431,7 +455,7 @@ describe('ScriptTransformer', () => {
     expect(result.sourceMapPath).toEqual(expect.any(String));
     expect(writeFileAtomic.sync).toBeCalledWith(
       result.sourceMapPath,
-      JSON.stringify(map),
+      JSON.stringify(expectedMap),
       {
         encoding: 'utf8',
       },

diff --git a/packages/jest-runtime/src/script_transformer.js b/packages/jest-runtime/src/script_transformer.js
@@ -151,24 +151,35 @@ export default class ScriptTransformer {
     return transform;
   }
 
-  _instrumentFile(filename: Path, content: string): string {
-    return babelTransform(content, {
+  _instrumentFile(filename: Path, input: TransformedSource): TransformedSource {
+    const istanbulConfig: any = {
+      compact: false,
+      // files outside `cwd` will not be instrumented
+      cwd: this._config.rootDir,
+      exclude: [],
+      useInlineSourceMaps: false,
+    }
+    // inject source map if we have it
+    if (input.map) {
+      istanbulConfig.inputSourceMap = input.map;
+    }
+
+    // instrument with babel-plugin-istanbul
+    const transformed = babelTransform(input.code, {
       auxiliaryCommentBefore: ' istanbul ignore next ',
       babelrc: false,
       filename,
       plugins: [
-        [
-          babelPluginIstanbul,
-          {
-            compact: false,
-            // files outside `cwd` will not be instrumented
-            cwd: this._config.rootDir,
-            exclude: [],
-            useInlineSourceMaps: false,
-          },
-        ],
+        [babelPluginIstanbul,istanbulConfig],
       ],
-    }).code;
+      sourceMap: !!input.map,
+    });
+
+    return {
+      code: transformed.code,
+      // ensure we return stringified source map if the input was
+      map: typeof input.map === 'string' ? JSON.stringify(transformed.map) : transformed.map,
+    };
   }
 
   _getRealPath(filepath: Path): Path {
@@ -243,10 +254,9 @@ export default class ScriptTransformer {
     }
 
     if (!transformWillInstrument && instrument) {
-      code = this._instrumentFile(filename, transformed.code);
-    } else {
-      code = transformed.code;
+      transformed = this._instrumentFile(filename, transformed);
     }
+    code = transformed.code;
 
     if (transformed.map) {
       const sourceMapContent =