Makes modular variant of the library available to Web Workers

Removes dedicated Web Worker build from webpack. Now automatically
detects whether we are running in a Web Worker context where needed.

Resolves #1514

.github/workflows/check.yml

@@ -21,5 +21,5 @@ jobs:
       - run: npm ci
       - run: npm run lint
       - run: npm run format:check
-      - run: npx tsc --noEmit ably.d.ts modules.d.ts build/ably-webworker.min.d.ts
+      - run: npx tsc --noEmit ably.d.ts modules.d.ts
       - run: npm audit --production

README.md

@@ -28,11 +28,7 @@ This SDK supports the following platforms:
 
 **TypeScript:** see [below](#typescript)
 
-**WebWorkers**: We build a separate bundle which supports running in a [Web Worker](https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API) context. You can import it like this:
-
-```js
-import Ably from 'ably/build/ably-webworker.min';
-```
+**WebWorkers:** Browser bundle supports running in a [Web Worker](https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API) context. You can also use a [modular variant](#modular-tree-shakable-variant) of the library in Web Workers.
 
 We regression-test the library against a selection of those (which will change over time, but usually consists of the versions that are supported upstream, plus old versions of IE).
 

package.json

@@ -57,7 +57,6 @@
     "async": "ably-forks/async#requirejs",
     "aws-sdk": "^2.1413.0",
     "chai": "^4.2.0",
-    "copy-webpack-plugin": "^11.0.0",
     "cors": "^2.8.5",
     "esbuild": "^0.18.10",
     "esbuild-plugin-umd-wrapper": "^1.0.7",

src/common/lib/util/utils.ts

@@ -571,3 +571,13 @@ export function arrEquals(a: any[], b: any[]) {
 export function throwMissingModuleError(moduleName: keyof ModulesMap): never {
   throw new ErrorInfo(`${moduleName} module not provided`, 40019, 400);
 }
+
+// from: https://stackoverflow.com/a/18002694
+export function isWebWorkerContext(): boolean {
+  // run this in global scope of window or worker. since window.self = window, we're ok
+  if (typeof WorkerGlobalScope !== 'undefined' && self instanceof WorkerGlobalScope) {
+    return true;
+  } else {
+    return false;
+  }
+}

src/common/types/IPlatformConfig.d.ts

@@ -27,5 +27,4 @@ export interface IPlatformConfig {
     byteLength: number,
     callback: (err: Error | null, result: ArrayBuffer | null) => void
   ) => void;
-  isWebworker?: boolean;
 }

src/platform/web/lib/http/request/fetchrequest.ts

@@ -5,7 +5,7 @@ import { RequestCallback, RequestCallbackHeaders, RequestParams } from 'common/t
 import Platform from 'common/platform';
 import Defaults from 'common/lib/util/defaults';
 import * as Utils from 'common/lib/util/utils';
-import { getGlobalObject } from 'common/lib/util/utils';
+import { getGlobalObject, isWebWorkerContext } from 'common/lib/util/utils';
 
 function isAblyError(responseBody: unknown, headers: Headers): responseBody is { error?: ErrorInfo } {
   return !!headers.get('x-ably-errorcode');
@@ -55,7 +55,7 @@ export default function fetchRequest(
     body: body as any,
   };
 
-  if (!Platform.Config.isWebworker) {
+  if (!isWebWorkerContext()) {
     requestInit.credentials = fetchHeaders.has('authorization') ? 'include' : 'same-origin';
   }
 

test/support/browser_file_list.js

@@ -3,7 +3,6 @@ window.__testFiles__.files = {
   'build/ably-nativescript.js': true,
   'build/ably-node.js': true,
   'build/ably-reactnative.js': true,
-  'build/ably-webworker.min.js': true,
   'build/ably.js': true,
   'build/ably.min.js': true,
   'browser/lib/util/base64.js': true,

webpack.config.js

@@ -2,7 +2,6 @@
 const path = require('path');
 const { BannerPlugin } = require('webpack');
 const banner = require('./src/fragments/license');
-const CopyPlugin = require('copy-webpack-plugin');
 // This is needed for baseUrl to resolve correctly from tsconfig
 const TsconfigPathsPlugin = require('tsconfig-paths-webpack-plugin');
 
@@ -64,26 +63,6 @@ const nodeConfig = {
   },
 };
 
-const browserConfig = {
-  ...baseConfig,
-  output: {
-    ...baseConfig.output,
-    filename: 'ably.js',
-  },
-  entry: {
-    index: platformPath('web'),
-  },
-  resolve: {
-    ...baseConfig.resolve,
-    fallback: {
-      crypto: false,
-    },
-  },
-  optimization: {
-    minimize: false,
-  },
-};
-
 const nativeScriptConfig = {
   ...baseConfig,
   output: {
@@ -137,38 +116,8 @@ const reactNativeConfig = {
   },
 };
 
-const webworkerConfig = {
-  target: ['webworker', 'es5'],
-  ...browserConfig,
-  entry: {
-    index: platformPath('web', 'index-webworker.ts'),
-  },
-  output: {
-    ...baseConfig.output,
-    filename: 'ably-webworker.min.js',
-    globalObject: 'this',
-  },
-  optimization: {
-    minimize: true,
-  },
-  performance: {
-    hints: 'warning',
-  },
-  plugins: [
-    new CopyPlugin({
-      patterns: [
-        {
-          from: path.resolve(__dirname, 'src', 'fragments', 'ably.d.ts'),
-          to: path.resolve(__dirname, 'build', 'ably-webworker.min.d.ts'),
-        },
-      ],
-    }),
-  ],
-};
-
 module.exports = {
   node: nodeConfig,
-  webworker: webworkerConfig,
   nativeScript: nativeScriptConfig,
   reactNative: reactNativeConfig,
 };