[FIX] Execution in IE11 (html mode)

Pin istanbul-lib-coverage to 2.0.3 as newer versions break usage in IE.
This is only a temporary workaround. Babel should be introduced to
transpile all browser code to be compatible with IE11.

Add integration test execution with Internet Explorer.
Currently this needs to be executed manually (no CI integration).

package.json

@@ -33,6 +33,7 @@
     "unit": "jest test/framework.test.js",
     "unit-coverage": "jest test/framework.test.js --coverage",
     "integration": "jest test/integration.test.js",
+    "integration-internet-explorer": "jest test/integration.test.js --browsers=IE",
     "dev": "webpack --watch --mode=development",
     "prepare": "webpack",
     "preversion": "npm test",
@@ -65,7 +66,7 @@
     "eslint-plugin-jest": "^22.16.0",
     "eslint-plugin-jsdoc": "^15.8.4",
     "execa": "^2.0.4",
-    "istanbul-lib-coverage": "^2.0.5",
+    "istanbul-lib-coverage": "2.0.3",
     "jest": "^24.9.0",
     "karma": "^4.3.0",
     "karma-chrome-launcher": "^3.1.0",

test/integration.test.js

@@ -4,7 +4,15 @@ const execa = require("execa");
 
 const registerIntegrationTest = async (configPath) => {
 	it(configPath, async () => {
-		await execa("karma", ["start", path.join(__dirname, configPath)], {
+		const args = [
+			"start",
+			path.join(__dirname, configPath)
+		];
+		if (process.argv[process.argv.length - 1] === "--browsers=IE") {
+			// Allow switching to IE by passing a CLI arg
+			args.push("--browsers=IE");
+		}
+		await execa("karma", args, {
 			cwd: __dirname,
 			stdio: "inherit",
 			preferLocal: true // allow executing local karma binary

test/integration/karma-base.conf.js

@@ -7,6 +7,7 @@ module.exports = function(config) {
 			require("../../"),
 			require("karma-coverage"),
 			require("karma-chrome-launcher"),
+			require("karma-ie-launcher"),
 			require("karma-qunit")
 		],
 

webpack.config.js

@@ -7,6 +7,7 @@ const allowedLicenses = [
 
 module.exports = {
 	mode: "production",
+	devtool: "none",
 	entry: {
 		"browser-bundle": "./lib/client/browser.js"
 	},