Support inline base64 source maps

src/assets/JSAsset.js

@@ -23,6 +23,8 @@ const GLOBAL_RE = /\b(?:process|__dirname|__filename|global|Buffer|define)\b/;
 const FS_RE = /\breadFileSync\b/;
 const SW_RE = /\bnavigator\s*\.\s*serviceWorker\s*\.\s*register\s*\(/;
 const WORKER_RE = /\bnew\s*Worker\s*\(/;
+const SOURCEMAP_RE = /\/\/\s*[@#]\s*sourceMappingURL\s*=\s*([^\s]+)/;
+const DATA_URL_RE = /^data:[^;]+(?:;charset=[^;]+)?;base64,(.*)/;
 
 class JSAsset extends Asset {
   constructor(name, options) {
@@ -107,26 +109,40 @@ class JSAsset extends Asset {
     walk.ancestor(this.ast, collectDependencies, this);
   }
 
-  async pretransform() {
+  async loadSourceMap() {
     // Get original sourcemap if there is any
-    let sourceMapLine = this.contents.lastIndexOf('//# sourceMappingURL=');
-    if (sourceMapLine > -1) {
-      let sourceMapReference = this.contents.substring(sourceMapLine + 21);
-      this.contents = this.contents.substring(0, sourceMapLine);
+    let match = this.contents.match(SOURCEMAP_RE);
+    if (match) {
+      this.contents = this.contents.replace(SOURCEMAP_RE, '');
+
+      let url = match[1];
+      let dataURLMatch = url.match(DATA_URL_RE);
 
       try {
-        this.sourceMap = JSON.parse(
-          await fs.readFile(
-            path.join(path.dirname(this.name), sourceMapReference)
-          )
-        );
+        let json;
+        if (dataURLMatch) {
+          json = new Buffer(dataURLMatch[1], 'base64').toString();
+        } else {
+          json = await fs.readFile(
+            path.join(path.dirname(this.name), url),
+            'utf8'
+          );
+        }
+
+        this.sourceMap = JSON.parse(json);
+
+        // Add as a dep so we watch the source map for changes.
+        this.addDependency(match[1], {includedInParent: true});
       } catch (e) {
         logger.warn(
           `Could not load existing sourcemap of ${this.relativeName}.`
         );
       }
     }
+  }
 
+  async pretransform() {
+    await this.loadSourceMap();
     await babel(this);
 
     // Inline environment variables

test/graphql.js

@@ -31,6 +31,7 @@ describe('graphql', function() {
           firstName
           lastName
         }
+
       `.definitions
     );
   });

test/integration/sourcemap-existing/sum.map

@@ -1,19 +1,11 @@
 {
   "version": 3,
+  "file": "sum.js",
+  "sourceRoot": "",
   "sources": [
-    "sum.js"
+    "sum.coffee"
   ],
-  "names": [
-    "sum",
-    "a",
-    "b",
-    "module",
-    "exports"
-  ],
-  "mappings": ";;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;AAAA,SAASA,GAAT,CAAaC,CAAb,EAAgBC,CAAhB,EAAmB;AACjB,SAAOD,IAAIC,CAAX;AACD;;AAEDC,OAAOC,OAAP,GAAiBJ,GAAjB",
-  "file": "sum.map",
-  "sourceRoot": '',
-  "sourcesContent": [
-    "function sum(a, b) {\n  return a + b;\n}\n\nmodule.exports = sum;\n\n"
-  ]
+  "names": [],
+  "mappings": ";AAAA;EAAA,MAAM,CAAC,OAAP,GAAiB,CAAA,SAAA,KAAA;WAAA,SAAC,CAAD,EAAI,CAAJ;aAAU,CAAA,GAAI;IAAd;EAAA,CAAA,CAAA,CAAA,IAAA;AAAjB",
+  "sourcesContent": ["module.exports = (a, b) => a + b"]
 }

test/integration/sourcemap-inline/index.js

@@ -0,0 +1,5 @@
+const sum = require('./sum');
+
+module.exports = function() {
+  return sum(1, 2);
+}

test/sourcemaps.js

@@ -220,7 +220,7 @@ describe('sourcemaps', function() {
       ]
     });
 
-    let jsOutput = fs.readFileSync(b.name).toString();
+    let jsOutput = await fs.readFile(b.name, 'utf8');
 
     let sourcemapReference = path.join(
       __dirname,
@@ -229,13 +229,47 @@ describe('sourcemaps', function() {
     );
 
     assert(
-      fs.existsSync(path.join(sourcemapReference)),
+      await fs.exists(path.join(sourcemapReference)),
+      'referenced sourcemap should exist'
+    );
+
+    let map = await fs.readFile(path.join(sourcemapReference), 'utf8');
+    assert(
+      map.indexOf('module.exports = (a, b) => a + b') > -1,
+      'Sourcemap should contain the existing sourcemap'
+    );
+    mapValidator(jsOutput, map);
+  });
+
+  it('should load inline sourcemaps of libraries', async function() {
+    let b = await bundle(__dirname + '/integration/sourcemap-inline/index.js');
+
+    assertBundleTree(b, {
+      name: 'index.js',
+      assets: ['index.js', 'sum.js'],
+      childBundles: [
+        {
+          type: 'map'
+        }
+      ]
+    });
+
+    let jsOutput = await fs.readFile(b.name, 'utf8');
+
+    let sourcemapReference = path.join(
+      __dirname,
+      '/dist/',
+      jsOutput.substring(jsOutput.lastIndexOf('//# sourceMappingURL') + 22)
+    );
+
+    assert(
+      await fs.exists(path.join(sourcemapReference)),
       'referenced sourcemap should exist'
     );
 
-    let map = fs.readFileSync(path.join(sourcemapReference)).toString();
+    let map = await fs.readFile(path.join(sourcemapReference), 'utf8');
     assert(
-      map.indexOf('return a + b;') > -1,
+      map.indexOf('module.exports = (a, b) => a + b') > -1,
       'Sourcemap should contain the existing sourcemap'
     );
     mapValidator(jsOutput, map);