fix: ES5 support

It seems that at least one package (`debug`) doesn't
provide code transpiled to ES5 through node_modules.
Since it by default imports from src/, a resolve alias
is added to point to the dist/debug.js file instead.

A new ES5 target is also added at `dist/es5`.

closes: AxisCommunications#158

README.md

@@ -13,6 +13,17 @@ stream transforms for Node & the Web.
 The primary purpose is to deal with RTP streams in a browser without
 the need to use plugins or Flash, but relying on the [Media Source Extensions](https://www.w3.org/TR/media-source/) standard, which is supported in all modern browsers.
 
+_Note for IE11 users_: if you want to build the library yourself for IE11 instead
+of using the provided bundle, you need import from `dist/es5` with the following fix in webpack:
+
+```
+alias: {
+  debug: 'debug/dist/debug.js',
+},
+```
+
+You can look at the `webpack.config.js` to see how it's used for building the bundle.
+
 ## Structure
 
 The library contains a collection of components that can be connected

package.json

@@ -14,9 +14,10 @@
     "lint": "tslint --project tsconfig.json --format stylish",
     "test": "jest --coverage",
     "verify": "yarn lint && yarn test",
-    "build": "yarn build:esm && yarn build:cjs && yarn build:bundle",
+    "build": "yarn build:esm && yarn build:cjs && yarn build:es5 && yarn build:bundle",
     "build:esm": "tsc -p tsconfig.json",
     "build:cjs": "tsc -p tsconfig.cjs.json",
+    "build:es5": "tsc -p tsconfig.es5.json",
     "build:bundle": "webpack",
     "rtsp": "rtsp-ws-server/start.sh",
     "dev": "webpack --mode development --watch",

tsconfig.es5.json

@@ -0,0 +1,22 @@
+{
+  "compilerOptions": {
+    /* Include Typescript declaration files */
+    "declaration": true,
+
+    /* Basic Options */
+    "target": "es5",
+    "downlevelIteration": true,
+    "module": "es2015",
+    "outDir": "./dist/es5",
+    "skipLibCheck": true,
+    "sourceMap": true,
+
+    /* Strict Type-Checking Options */
+    "strict": true,
+
+    /* Module Resolution Options */
+    "moduleResolution": "node",
+    "esModuleInterop": true
+  },
+  "include": ["lib/**/*"]
+}

tsconfig.json

@@ -2,7 +2,7 @@
   "compilerOptions": {
     /* Include Typescript declaration files */
     "declaration": true,
-    
+
     /* Basic Options */
     "target": "es2015",
     "module": "es2015",

webpack.config.js

@@ -9,6 +9,12 @@ module.exports = {
   },
   resolve: {
     extensions: ['.ts', '.js'],
+    // The debug packages resolves to src/debug.js by default
+    // which doesn't work on IE11 (it's not ES5), but it seems
+    // that the dist/debug.js file does work.
+    alias: {
+      debug: 'debug/dist/debug.js',
+    },
   },
   module: {
     rules: [