feat: support loading node core modules (#76)

* Allow worker-loader to load node core modules
* added tests for all targets
* change this.options.target to this.target

Author: FrogTheFrog

index.js

@@ -2,6 +2,7 @@
 
 const path = require('path');
 const WebWorkerTemplatePlugin = require('webpack/lib/webworker/WebWorkerTemplatePlugin');
+const NodeTargetPlugin = require('webpack/lib/node/NodeTargetPlugin');
 const SingleEntryPlugin = require('webpack/lib/SingleEntryPlugin');
 const loaderUtils = require('loader-utils');
 
@@ -38,6 +39,9 @@ module.exports.pitch = function pitch(request) {
   }
   const workerCompiler = this._compilation.createChildCompiler('worker', outputOptions);
   workerCompiler.apply(new WebWorkerTemplatePlugin(outputOptions));
+  if (this.target !== 'webworker' && this.target !== 'web') {
+    workerCompiler.apply(new NodeTargetPlugin());
+  }
   workerCompiler.apply(new SingleEntryPlugin(this.context, `!!${request}`, 'main'));
   if (this.options && this.options.worker && this.options.worker.plugins) {
     this.options.worker.plugins.forEach(plugin => workerCompiler.apply(plugin));

test/fixtures/nodejs-core-modules/entry.js

@@ -0,0 +1 @@
+const Worker = require('../../../index.js!./worker.js');

test/fixtures/nodejs-core-modules/worker.js

@@ -0,0 +1 @@
+const fs = require('fs');

test/index.js

@@ -180,4 +180,48 @@ describe('worker-loader', () => {
       assert.notEqual(readFile(bundleFile).indexOf('// w2 inlined without fallback'), -1);
     })
   );
+
+  ['web', 'webworker'].forEach((target) => {
+    it(`should have missing dependencies (${target})`, () =>
+      makeBundle('nodejs-core-modules', {
+        target,
+        module: {
+          rules: [
+            {
+              test: /worker\.js$/,
+              loader: '../index.js',
+              options: {
+                inline: true,
+                fallback: false,
+              },
+            },
+          ],
+        },
+      }).then((stats) => {
+        assert.notEqual(stats.compilation.missingDependencies.length, 0);
+      })
+    );
+  });
+
+  ['node', 'async-node', 'node-webkit', 'atom', 'electron', 'electron-main', 'electron-renderer'].forEach((target) => {
+    it(`should not have missing dependencies (${target})`, () =>
+      makeBundle('nodejs-core-modules', {
+        target,
+        module: {
+          rules: [
+            {
+              test: /worker\.js$/,
+              loader: '../index.js',
+              options: {
+                inline: true,
+                fallback: false,
+              },
+            },
+          ],
+        },
+      }).then((stats) => {
+        assert.equal(stats.compilation.missingDependencies.length, 0);
+      })
+    );
+  });
 });