Scope hoisting for ES6 and CommonJS modules (#1135)

packages/core/parcel/package.json

@@ -106,8 +106,7 @@
     "format": "prettier --write \"./{src,bin,test}/**/*.{js,json,md}\"",
     "build": "yarn minify && babel src -d lib && ncp src/builtins lib/builtins",
     "prepublish": "yarn build",
-    "minify":
-      "terser -c -m -o src/builtins/prelude.min.js src/builtins/prelude.js",
+    "minify": "terser -c -m -o src/builtins/prelude.min.js src/builtins/prelude.js && terser -c -m -o src/builtins/prelude2.min.js src/builtins/prelude2.js",
     "precommit": "npm run lint && lint-staged",
     "lint":
       "eslint . && prettier \"./{src,bin,test}/**/*.{js,json,md}\" --list-different",

packages/core/parcel/src/Bundler.js

@@ -35,7 +35,7 @@ class Bundler extends EventEmitter {
 
     this.resolver = new Resolver(this.options);
     this.parser = new Parser(this.options);
-    this.packagers = new PackagerRegistry();
+    this.packagers = new PackagerRegistry(this.options);
     this.cache = this.options.cache ? new FSCache(this.options) : null;
     this.delegate = options.delegate || {};
     this.bundleLoaders = {};
@@ -91,6 +91,14 @@ class Bundler extends EventEmitter {
     const watch =
       typeof options.watch === 'boolean' ? options.watch : !isProduction;
     const target = options.target || 'browser';
+    const hmr =
+      target === 'node'
+        ? false
+        : typeof options.hmr === 'boolean'
+          ? options.hmr
+          : watch;
+    const scopeHoist =
+      options.scopeHoist !== undefined ? options.scopeHoist : false;
     return {
       production: isProduction,
       outDir: Path.resolve(options.outDir || 'dist'),
@@ -104,19 +112,15 @@ class Bundler extends EventEmitter {
       minify:
         typeof options.minify === 'boolean' ? options.minify : isProduction,
       target: target,
-      hmr:
-        target === 'node'
-          ? false
-          : typeof options.hmr === 'boolean'
-            ? options.hmr
-            : watch,
+      hmr: hmr,
       https: options.https || false,
       logLevel: isNaN(options.logLevel) ? 3 : options.logLevel,
       entryFiles: this.entryFiles,
       hmrPort: options.hmrPort || 0,
       rootDir: getRootDir(this.entryFiles),
       sourceMaps:
-        typeof options.sourceMaps === 'boolean' ? options.sourceMaps : true,
+        (typeof options.sourceMaps === 'boolean' ? options.sourceMaps : true) &&
+        !scopeHoist,
       hmrHostname:
         options.hmrHostname ||
         (options.target === 'electron' ? 'localhost' : ''),
@@ -126,6 +130,7 @@ class Bundler extends EventEmitter {
         typeof options.autoinstall === 'boolean'
           ? options.autoinstall
           : !isProduction,
+      scopeHoist: scopeHoist,
       contentHash:
         typeof options.contentHash === 'boolean'
           ? options.contentHash
@@ -246,6 +251,8 @@ class Bundler extends EventEmitter {
         asset.invalidateBundle();
       }
 
+      logger.status(emoji.progress, `Producing bundles...`);
+
       // Create a root bundle to hold all of the entry assets, and add them to the tree.
       this.mainBundle = new Bundle();
       for (let asset of this.entryAssets) {
@@ -271,6 +278,8 @@ class Bundler extends EventEmitter {
         this.hmr.emitUpdate(changedAssets);
       }
 
+      logger.status(emoji.progress, `Packaging...`);
+
       // Package everything up
       this.bundleHashes = await this.mainBundle.package(
         this,
@@ -318,7 +327,7 @@ class Bundler extends EventEmitter {
     }
 
     await this.loadPlugins();
-    
+
     if (!this.options.env) {
       await loadEnv(Path.join(this.options.rootDir, 'index'));
       this.options.env = process.env;
@@ -508,14 +517,17 @@ class Bundler extends EventEmitter {
     let processed = this.cache && (await this.cache.read(asset.name));
     let cacheMiss = false;
     if (!processed || asset.shouldInvalidate(processed.cacheData)) {
-      processed = await this.farm.run(asset.name);
+      processed = await this.farm.run(asset.name, asset.id);
+      processed.id = asset.id;
       cacheMiss = true;
     }
 
     asset.endTime = Date.now();
     asset.buildTime = asset.endTime - asset.startTime;
+    asset.id = processed.id;
     asset.generated = processed.generated;
     asset.hash = processed.hash;
+    asset.cacheData = processed.cacheData;
 
     // Call the delegate to get implicit dependencies
     let dependencies = processed.dependencies;
@@ -535,6 +547,7 @@ class Bundler extends EventEmitter {
           // that changing it triggers a recompile of the parent.
           this.watch(dep.name, asset);
         } else {
+          dep.parent = asset.name;
           let assetDep = await this.resolveDep(asset, dep);
           if (assetDep) {
             await this.loadAsset(assetDep);

packages/core/parcel/src/FSCache.js

@@ -6,7 +6,7 @@ const pkg = require('../package.json');
 const logger = require('./Logger');
 
 // These keys can affect the output, so if they differ, the cache should not match
-const OPTION_KEYS = ['publicURL', 'minify', 'hmr', 'target'];
+const OPTION_KEYS = ['publicURL', 'minify', 'hmr', 'target', 'scopeHoist'];
 
 class FSCache {
   constructor(options) {

packages/core/parcel/src/Parser.js

@@ -61,8 +61,8 @@ class Parser {
     this.extensions[ext.toLowerCase()] = parser;
   }
 
-  findParser(filename) {
-    if (/[*+{}]/.test(filename) && glob.hasMagic(filename)) {
+  findParser(filename, fromPipeline) {
+    if (!fromPipeline && /[*+{}]/.test(filename) && glob.hasMagic(filename)) {
       return GlobAsset;
     }
 

packages/core/parcel/src/Pipeline.js

@@ -11,13 +11,15 @@ class Pipeline {
     this.parser = new Parser(options);
   }
 
-  async process(path, isWarmUp) {
+  async process(path, id, isWarmUp) {
     let options = this.options;
     if (isWarmUp) {
       options = Object.assign({isWarmUp}, options);
     }
 
     let asset = this.parser.getAsset(path, options);
+    asset.id = id;
+
     let generated = await this.processAsset(asset);
     let generatedMap = {};
     for (let rendition of generated) {
@@ -52,17 +54,19 @@ class Pipeline {
       // Find an asset type for the rendition type.
       // If the asset is not already an instance of this asset type, process it.
       let AssetType = this.parser.findParser(
-        asset.name.slice(0, -inputType.length) + type
+        asset.name.slice(0, -inputType.length) + type,
+        true
       );
       if (!(asset instanceof AssetType)) {
-        let opts = Object.assign({rendition}, asset.options);
+        let opts = Object.assign({}, asset.options, {rendition});
         let subAsset = new AssetType(asset.name, opts);
+        subAsset.id = asset.id;
         subAsset.contents = value;
         subAsset.dependencies = asset.dependencies;
+        subAsset.cacheData = Object.assign(asset.cacheData, subAsset.cacheData);
 
         let processed = await this.processAsset(subAsset);
         generated = generated.concat(processed);
-        Object.assign(asset.cacheData, subAsset.cacheData);
         asset.hash = md5(asset.hash + subAsset.hash);
       } else {
         generated.push(rendition);
@@ -98,7 +102,8 @@ class Pipeline {
       yield {
         type,
         value: asset.generated[type],
-        final: true
+        // for scope hoisting, we need to post process all JS
+        final: !(type === 'js' && this.options.scopeHoist)
       };
     }
   }

packages/core/parcel/src/SourceMap.js

@@ -149,8 +149,8 @@ class SourceMap {
         column: mapping.original.column
       });
 
-      if (!originalMapping.line) {
-        return false;
+      if (!originalMapping || !originalMapping.line) {
+        return;
       }
 
       this.addMapping({
@@ -182,7 +182,60 @@ class SourceMap {
     return this;
   }
 
-  findClosest(line, column, key = 'original') {
+  findClosestGenerated(line, column) {
+    if (line < 1) {
+      throw new Error('Line numbers must be >= 1');
+    }
+
+    if (column < 0) {
+      throw new Error('Column numbers must be >= 0');
+    }
+
+    if (this.mappings.length < 1) {
+      return undefined;
+    }
+
+    let startIndex = 0;
+    let stopIndex = this.mappings.length - 1;
+    let middleIndex = (stopIndex + startIndex) >>> 1;
+
+    while (
+      startIndex < stopIndex &&
+      this.mappings[middleIndex].generated.line !== line
+    ) {
+      let mid = this.mappings[middleIndex].generated.line;
+      if (line < mid) {
+        stopIndex = middleIndex - 1;
+      } else if (line > mid) {
+        startIndex = middleIndex + 1;
+      }
+      middleIndex = (stopIndex + startIndex) >>> 1;
+    }
+
+    let mapping = this.mappings[middleIndex];
+    if (!mapping || mapping.generated.line !== line) {
+      return this.mappings.length - 1;
+    }
+
+    while (
+      middleIndex >= 1 &&
+      this.mappings[middleIndex - 1].generated.line === line
+    ) {
+      middleIndex--;
+    }
+
+    while (
+      middleIndex < this.mappings.length - 1 &&
+      this.mappings[middleIndex + 1].generated.line === line &&
+      column > this.mappings[middleIndex].generated.column
+    ) {
+      middleIndex++;
+    }
+
+    return middleIndex;
+  }
+
+  findClosest(line, column, key) {
     if (line < 1) {
       throw new Error('Line numbers must be >= 1');
     }
@@ -211,7 +264,7 @@ class SourceMap {
       middleIndex = Math.floor((stopIndex + startIndex) / 2);
     }
 
-    let mapping = this.mappings[middleIndex];
+    var mapping = this.mappings[middleIndex];
     if (!mapping || mapping[key].line !== line) {
       return this.mappings.length - 1;
     }
@@ -235,16 +288,20 @@ class SourceMap {
   }
 
   originalPositionFor(generatedPosition) {
-    let index = this.findClosest(
+    let index = this.findClosestGenerated(
       generatedPosition.line,
-      generatedPosition.column,
-      'generated'
+      generatedPosition.column
     );
+    let mapping = this.mappings[index];
+    if (!mapping) {
+      return null;
+    }
+
     return {
-      source: this.mappings[index].source,
-      name: this.mappings[index].name,
-      line: this.mappings[index].original.line,
-      column: this.mappings[index].original.column
+      source: mapping.source,
+      name: mapping.name,
+      line: mapping.original.line,
+      column: mapping.original.column
     };
   }
 

packages/core/parcel/src/assets/CSSAsset.js

@@ -125,7 +125,7 @@ class CSSAsset extends Asset {
       {
         type: 'js',
         value: js,
-        final: true
+        hasDependencies: false
       }
     ];
   }

packages/core/parcel/src/assets/GLSLAsset.js

@@ -53,9 +53,7 @@ class GLSLAsset extends Asset {
     const glslifyBundle = await localRequire('glslify-bundle', this.name);
     let glsl = glslifyBundle(this.ast);
 
-    return {
-      js: `module.exports=${JSON.stringify(glsl)};`
-    };
+    return `module.exports=${JSON.stringify(glsl)};`;
   }
 }
 

packages/core/parcel/src/assets/GlobAsset.js

@@ -38,9 +38,12 @@ class GlobAsset extends Asset {
   }
 
   generate() {
-    return {
-      js: 'module.exports = ' + generate(this.contents) + ';'
-    };
+    return [
+      {
+        type: 'js',
+        value: 'module.exports = ' + generate(this.contents) + ';'
+      }
+    ];
   }
 }
 

packages/core/parcel/src/assets/GraphqlAsset.js

@@ -13,9 +13,7 @@ class GraphqlAsset extends Asset {
   }
 
   generate() {
-    return {
-      js: `module.exports=${JSON.stringify(this.ast, false, 2)};`
-    };
+    return `module.exports=${JSON.stringify(this.ast, false, 2)};`;
   }
 }