Issue 5535 - Replace our module system with webpack

webpack_runner.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+"use strict";
+
 const path = require("path");
 const process = require("process");
 
 const MemoryFS = require("memory-fs");
 const webpack = require("webpack");
 
-let {BOUNDARY, BUNDLES, EXTENSION_PATH,
-     RESOLVE_PATHS} = JSON.parse(process.argv[2]);
+// We read the configuration from STDIN rather than as an argument to improve
+// the output on error. Otherwise the (fairly huge) configuration is printed
+// along with the actual error message.
+let inputChunks = [];
+process.stdin.setEncoding("utf-8");
+process.stdin.on("data", chunk => { inputChunks.push(chunk); });
+process.stdin.on("end", () =>
+{
+  let {bundles, extension_path,
+       info_module, resolve_paths} = JSON.parse(inputChunks.join(""));
 
-// Since the cost of starting Node.js and loading all the modules is hugely
-// larger than actually producing bundles we avoid paying it multiple times.
-// To acheive this we output all the required bundles - along with their
-// names - in one go.
-let options = [];
-for (let {BUNDLE_NAME, ENTRY_POINTS} of BUNDLES)
-{
-  options.push({
-    context: EXTENSION_PATH,
-    devtool: "source-map",
-    module: {
-      rules: [{
-        include: path.join(EXTENSION_PATH, "lib", "info.js"),
-        use: ["info-loader"]
-      }]
-    },
-    entry: ENTRY_POINTS,
-    output: {
-      path: "/",
-      filename: BUNDLE_NAME
-    },
-    resolve: {
-      modules: RESOLVE_PATHS,
-      alias: {
-        // Prevent builtin Node.js modules from being used instead of our own
-        // when the names clash. Once relative paths are used this won't be
-        // necessary.
-        url$: "url.js",
-        events$: "events.js",
-        punycode$: "punycode.js"
+  // The contents of the info module is passed to us as a string from the Python
+  // packager and we pass it through to our custom loader now so it is available
+  // at bundle time.
+  require("./info-loader").setInfoModule(info_module);
+
+  // Since the cost of starting Node.js and loading all the modules is hugely
+  // larger than actually producing bundles we avoid paying it multiple times,
+  // instead producing all the bundles in one go.
+  let options = [];
+  for (let {bundle_name, entry_points} of bundles)
+  {
+    options.push({
+      context: extension_path,
+      devtool: "source-map",
+      module: {
+        rules: [{
+          include: path.join(__dirname, "info.js"),
+          use: ["info-loader"]
+        }]
       },
-      plugins: [
-        function()
-        {
-          // Our old module system in packagerChrome.py used to prefix
-          // module names with the name of their parent directory and an
-          // underscore - but only when that directory wasn't called
-          // "lib". This plugin is for backwards compatability, but can
-          // be removed once use of that deprecated syntax has been
-          // replaced.
-          this.plugin("described-resolve", (request, callback) =>
+      entry: entry_points,
+      output: {
+        path: "/",
+        filename: bundle_name
+      },
+      resolve: {
+        modules: resolve_paths,
+        alias: {
+          // To use our custom loader for the info module we must first set up
+          // an alias to a file that exists.
+          info$: path.join(__dirname, "info.js"),
+          // Prevent builtin Node.js modules from being used instead of our own
+          // when the names clash. Once relative paths are used this won't be
+          // necessary.
+          url$: "url.js",
+          events$: "events.js",
+          punycode$: "punycode.js"
+        },
+        plugins: [
+          function()
           {
-            let target = request.request;
+            // Our old module system in packagerChrome.py used to prefix
+            // module names with the name of their parent directory and an
+            // underscore - but only when that directory wasn't called
+            // "lib". This plugin is for backwards compatability, but can
+            // be removed once use of that deprecated syntax has been
+            // replaced.
+            this.plugin("described-resolve", (request, callback) =>
+            {
+              let target = request.request;
 
-            let prefix_index = target.indexOf("_");
-            if (prefix_index == -1)
-              return callback();
+              let prefixIndex = target.indexOf("_");
+              if (prefixIndex == -1)
+                return callback();
 
-            let prefix = target.substring(0, prefix_index);
-            if (prefix == "lib")
-              return callback();
+              let prefix = target.substring(0, prefixIndex);
+              if (prefix == "lib")
+                return callback();
 
-            let fixed_target = path.join(prefix,
-                                         target.substring(prefix_index + 1));
-            return this.doResolve(
-              "resolve", Object.assign({}, request, {request: fixed_target}),
-              "Changed prefixed path using legacy buildtools syntax from " +
-              target + " to " + fixed_target,
-              callback
-            );
-          });
-        }
-      ]
-    },
-    resolveLoader: {
-      modules: [path.resolve(__dirname)]
+              let fixedTarget = path.join(prefix,
+                                           target.substring(prefixIndex + 1));
+              return this.doResolve(
+                "resolve", Object.assign({}, request, {request: fixedTarget}),
+                "Changed prefixed path using legacy buildtools syntax from " +
+                target + " to " + fixedTarget,
+                callback
+              );
+            });
+          }
+        ]
+      },
+      resolveLoader: {
+        modules: [path.resolve(__dirname)]
+      }
+    });
+  }
+
+  // Based on this example
+  // https://webpack.js.org/api/node/#custom-file-systems
+  let memoryFS = new MemoryFS();
+  let webpackCompiler = webpack(options);
+
+  webpackCompiler.outputFileSystem = memoryFS;
+  webpackCompiler.run((err, stats) =>
+  {
+    // Error handling is based on this example
+    // https://webpack.js.org/api/node/#error-handling
+    if (err)
+    {
+      let reason = err.stack || err;
+      if (err.details)
+        reason += "\n" + err.details;
+      throw new Error(reason);
+    }
+    else if (stats.hasErrors())
+      throw new Error(stats.toJson().errors.join("\n"));
+    else
+    {
+      let files = {};
+
+      for (let config of options)
+      {
+        let filepath = path.join(config.output.path, config.output.filename);
+        let mappath = filepath + ".map";
+        files[filepath] = memoryFS.readFileSync(filepath, "utf-8");
+        files[mappath] = memoryFS.readFileSync(mappath, "utf-8");
+      }
+
+      console.log(JSON.stringify(files));
     }
   });
-}
-
-// Based on this example
-// https://webpack.js.org/api/node/#custom-file-systems
-let memoryFS = new MemoryFS();
-let webpackCompiler = webpack(options);
-
-webpackCompiler.outputFileSystem = memoryFS;
-webpackCompiler.run((err, stats) =>
-{
-  // Error handling is based on this example
-  // https://webpack.js.org/api/node/#error-handling
-  if (err)
-  {
-    let reason = err.stack || err;
-    if (err.details)
-      reason += "\n" + err.details;
-    throw new Error(reason);
-  }
-  else if (stats.hasErrors())
-    throw new Error(stats.toJson().errors.join("\n"));
-  else
-  {
-    for (let config of options)
-    {
-      let filepath = path.join(config.output.path, config.output.filename);
-      let mappath = filepath + ".map";
-      console.log(filepath, BOUNDARY,
-                  memoryFS.readFileSync(filepath, "utf-8"), BOUNDARY,
-                  mappath, BOUNDARY,
-                  memoryFS.readFileSync(mappath, "utf-8"), BOUNDARY);
-      memoryFS.unlinkSync(filepath);
-      memoryFS.unlinkSync(mappath);
-    }
-  }
 });