From 18769b704b3efca1559bf09d50ed5a01994b9ead Mon Sep 17 00:00:00 2001
From: Alex Landau <alandau@palantir.com>
Date: Wed, 16 Oct 2019 13:15:09 -0700
Subject: [PATCH] Don't fail the test suite when convert-source-map throws an
 error

Fixes #8966.
---
 .../jest-transform/src/ScriptTransformer.ts   | 14 +++++----
 .../src/__tests__/script_transformer.test.js  | 29 +++++++++++++++++++
 2 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/packages/jest-transform/src/ScriptTransformer.ts b/packages/jest-transform/src/ScriptTransformer.ts
index b2765e909a35..577b1e43f530 100644
--- a/packages/jest-transform/src/ScriptTransformer.ts
+++ b/packages/jest-transform/src/ScriptTransformer.ts
@@ -296,12 +296,16 @@ export default class ScriptTransformer {
     }
 
     if (!transformed.map) {
-      //Could be a potential freeze here.
-      //See: https://github.com/facebook/jest/pull/5177#discussion_r158883570
-      const inlineSourceMap = sourcemapFromSource(transformed.code);
+      try {
+        //Could be a potential freeze here.
+        //See: https://github.com/facebook/jest/pull/5177#discussion_r158883570
+        const inlineSourceMap = sourcemapFromSource(transformed.code);
 
-      if (inlineSourceMap) {
-        transformed.map = inlineSourceMap.toJSON();
+        if (inlineSourceMap) {
+          transformed.map = inlineSourceMap.toJSON();
+        }
+      } catch (e) {
+        // Error processing the source map; proceed as if it doesn't exist.
       }
     }
 
diff --git a/packages/jest-transform/src/__tests__/script_transformer.test.js b/packages/jest-transform/src/__tests__/script_transformer.test.js
index 7a826e079600..3d35ea6e3a69 100644
--- a/packages/jest-transform/src/__tests__/script_transformer.test.js
+++ b/packages/jest-transform/src/__tests__/script_transformer.test.js
@@ -406,6 +406,7 @@ describe('ScriptTransformer', () => {
     });
     expect(result.sourceMapPath).toEqual(expect.any(String));
     const mapStr = JSON.stringify(map);
+    expect(writeFileAtomic.sync).toBeCalledTimes(2);
     expect(writeFileAtomic.sync).toBeCalledWith(result.sourceMapPath, mapStr, {
       encoding: 'utf8',
     });
@@ -434,6 +435,7 @@ describe('ScriptTransformer', () => {
       collectCoverage: true,
     });
     expect(result.sourceMapPath).toEqual(expect.any(String));
+    expect(writeFileAtomic.sync).toBeCalledTimes(2);
     expect(writeFileAtomic.sync).toBeCalledWith(
       result.sourceMapPath,
       sourceMap,
@@ -441,6 +443,32 @@ describe('ScriptTransformer', () => {
     );
   });
 
+  it('ignores the inlined source map from the preprocessor if parsing it fails', () => {
+    config = {
+      ...config,
+      transform: [['^.+\\.js$', 'preprocessor-with-sourcemaps']],
+    };
+    const scriptTransformer = new ScriptTransformer(config);
+
+    const sourceMap = JSON.stringify({
+      mappings: 'AAAA,IAAM,CAAC,GAAW,CAAC,CAAC',
+      version: 3,
+    });
+
+    const content =
+      'var x = 1;\n' +
+      '//# sourceMappingURL=data:application/json;base64,' +
+      Buffer.from(sourceMap).toString('base64').slice(0, 16);
+
+    require('preprocessor-with-sourcemaps').process.mockReturnValue(content);
+
+    const result = scriptTransformer.transform('/fruits/banana.js', {
+      collectCoverage: true,
+    });
+    expect(result.sourceMapPath).toBeNull();
+    expect(writeFileAtomic.sync).toBeCalledTimes(1);
+  });
+
   it('writes source maps if given by the transformer', () => {
     config = {
       ...config,
@@ -462,6 +490,7 @@ describe('ScriptTransformer', () => {
       collectCoverage: true,
     });
     expect(result.sourceMapPath).toEqual(expect.any(String));
+    expect(writeFileAtomic.sync).toBeCalledTimes(2);
     expect(writeFileAtomic.sync).toBeCalledWith(
       result.sourceMapPath,
       JSON.stringify(map),