Issue 5079, 5516 - Use webpack for browser tests, modules for content scripts

chromium_process.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2017 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
@@ skipping 10 matching lines @@
 "use strict";
 
 const childProcess = require("child_process");
 const fs = require("fs");
 const https = require("https");
 const os = require("os");
 const path = require("path");
 
 const extractZip = require("extract-zip");
 const remoteInterface = require("chrome-remote-interface");
-const webpack = require("webpack");
-const MemoryFS = require("memory-fs");

[Wladimir Palant, 2017/08/17 10:05:38]

I assume that this module exists because WebPack is using it? Still, if we are
using it we should add it as our dependency explicitly.

Also a nit: I'm using the Python style for importing modules here, for better
overview. So please sort the imports of third-party modules alphabetically.

[kzar, 2017/08/17 12:40:21]

Done.

 
 const CHROMIUM_REVISION = 467222;
 
 function rmdir(dirPath)
 {
   for (let file of fs.readdirSync(dirPath))
   {
     let filePath = path.join(dirPath, file);
     try
     {
@@ skipping 200 matching lines @@
     return new Promise((resolve, reject) =>
     {
       setTimeout(() =>
       {
         connectRemoteInterface(attempt + 1).then(resolve).catch(reject);
       }, 200);
     });
   });
 }
 
-function webpackInMemory(bundleFilename, options)
-{
-  // Based on this example https://webpack.js.org/api/node/#custom-file-systems
-  let memoryFS = new MemoryFS();
-
-  options.output = {filename: bundleFilename, path: "/"};
-  let webpackCompiler = webpack(options);
-  webpackCompiler.outputFileSystem = memoryFS;

[Wladimir Palant, 2017/08/17 10:05:37]

Nit: It's better to put all the statements above inside the promise as well.
This way, we can rely on the function not throwing but only rejecting the
promise on error.

[kzar, 2017/08/17 12:40:21]

Done.

-  return new Promise((resolve, reject) =>
-  {
-    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;
-        reject(reason);
-      }
-      else if (stats.hasErrors())
-        reject(stats.toJson().errors);
-      else
-      {
-        let bundle = memoryFS.readFileSync("/" + bundleFilename, "utf-8");
-        memoryFS.unlink("/" + bundleFilename, () => { resolve(bundle); });

[Wladimir Palant, 2017/08/17 10:05:38]

Nit: Use memoryFS.unlinkSync() here to make this more straightforward? Besides,
this callback doesn't look like it would be accepted by ESLint.

[kzar, 2017/08/17 12:40:21]

Done.

-      }
-    });
-  });
-}
-
-function runBrowserTests(browserTestModules)
-{
-  // We need to navigate to this directory because about:blank won't be allowed
-  // to load file:/// URLs.
-  let initialPage = require("url").format({
-    protocol: "file",
-    slashes: "true",
-    pathname: path.resolve(process.cwd(), __dirname).split(path.sep).join("/")
-  });

[Wladimir Palant, 2017/08/17 10:07:30]

Actually, this shouldn't be necessary any more. Running the tests on about:blank
should be fine, we are no longer loading any file:/// URLs.

[kzar, 2017/08/17 12:40:21]

Done.

-
-  let bootstrapPath = path.join(__dirname, "test", "browser", "_bootstrap.js");
-  let nodeunitPath = path.join(__dirname, "node_modules", "nodeunit",
-                               "examples", "browser", "nodeunit.js");
-
+function runScript(script, scriptName, scriptArgs)
+{
   return connectRemoteInterface().then(async client =>
   {
     try
     {
-      let {Runtime, Log, Console, Page} = client;
+      let {Runtime, Log, Console} = client;
 
       await Log.enable();
       Log.entryAdded(({entry}) =>
       {
         reportMessage(entry.text, entry.level);
       });
 
       await Console.enable();
       Console.messageAdded(({message}) =>
       {
         reportMessage(message.text, message.level);
       });
 
-      await Page.navigate({url: initialPage});
-
       await Runtime.enable();
-
-      let bundleFilename = "bundle.js";
-      let bundle = await webpackInMemory(bundleFilename, {
-        entry: bootstrapPath,
-        module: {
-          rules: [{
-            resource: nodeunitPath,
-            // I would have rathered use exports-loader here, to avoid treating

[Wladimir Palant, 2017/08/17 10:05:37]

"rather used"?

[kzar, 2017/08/17 12:40:21]

Done.

-            // nodeunit as a global. Unfortunately the nodeunit browser example
-            // script is quite slopily put together, if exports isn't falsey it
-            // breaks! As a workaround we need to use script-loader, which means
-            // that exports is falsey for that script as a side-effect.
-            use: ["script-loader"]
-          }]
-        },
-        resolve: {
-          alias: {
-            nodeunit$: nodeunitPath
-          },
-          modules: [path.resolve(__dirname, "lib")]
-        }
-      });
-
       let compileResult = await Runtime.compileScript({
-        expression: bundle,
-        sourceURL: bundleFilename,
+        expression: script,
+        sourceURL: scriptName,
         persistScript: true
       });
       if (compileResult.exceptionDetails)
-        throwException(compileResult.exceptionDetails, bootstrapPath);
+        throwException(compileResult.exceptionDetails, scriptName);
 
       let runResult = await Runtime.runScript({
         scriptId: compileResult.scriptId
       });
       if (runResult.exceptionDetails)
-        throwException(runResult.exceptionDetails, bootstrapPath);
+        throwException(runResult.exceptionDetails, scriptName);
 
       let callResult = await Runtime.callFunctionOn({
         objectId: runResult.result.objectId,
-        functionDeclaration: "function(...modules) {return this(modules);}",
-        arguments: browserTestModules.map(module => ({value: module}))
+        functionDeclaration: "function(...args) { return this(...args); }",
+        arguments: scriptArgs.map(arg => ({value: arg}))
       });
       if (callResult.exceptionDetails)
-        throwException(callResult.exceptionDetails, bootstrapPath);
+        throwException(callResult.exceptionDetails, scriptName);
 
       let promiseResult = await Runtime.awaitPromise({
         promiseObjectId: callResult.result.objectId
       });
       if (promiseResult.exceptionDetails)
-        throwException(promiseResult.exceptionDetails, bootstrapPath);
+        throwException(promiseResult.exceptionDetails, scriptName);
     }
     finally
     {
       client.close();
     }
   });
 }
 
-module.exports = function(browserTestFiles)
+module.exports = function(script, scriptName, ...scriptArgs)
 {
   return ensureChromium().then(chromiumPath =>
   {
     let child = startChromium(chromiumPath);
     return Promise.race([
       child.done,
-      runBrowserTests(
-        browserTestFiles.map(
-          m => "." + path.sep + path.relative(path.join("test", "browser"), m)

[Wladimir Palant, 2017/08/17 10:05:37]

The point here is generating a list of module names suitable for require(). This
means that path.sep is wrong - it will be "\" on Windows, yet path separator in
module names is always "/".

Also, you are building paths relative to test/browser - this is assuming that
the current directory is pointing to repository root. This should be
path.join(__dirname, "test", "browser").

Besides, it seems that you should actually return 
path.relative(path.join(__dirname, "test", "browser"), m).replace(/\.js$/, "")
here. This way you can use require("./" + module + ".js") in _bootstrap.js
without having to create an explicit context.

[kzar, 2017/08/17 12:40:21]

Done.

-        )
-      )
+      runScript(script, scriptName, scriptArgs)
     ]).then(result =>
     {
       child.kill();
       return result;
     }).catch(error =>
     {
       child.kill();
       throw error;
     });
   });
 };