Add Jest matchers & assertions

Author: developit

README.md

@@ -2,6 +2,7 @@
 
 A simplified zero-configuration wrapper around [Karma], [Webpack], [Jasmine] & [Puppeteer].
 
+Think of it like Jest for cross-browser testing (it uses the same [expect syntax](https://jestjs.io/docs/en/using-matchers)).
 
 ## Why do I want this?
 

package.json

@@ -45,6 +45,7 @@
     "babel-plugin-istanbul": "^5.2.0",
     "chalk": "^2.3.0",
     "dlv": "^1.1.3",
+    "expect": "^24.9.0",
     "istanbul-instrumenter-loader": "^3.0.1",
     "jasmine-core": "^3.3.0",
     "karma": "^4.3.0",

src/configure.js

@@ -218,8 +218,13 @@ export default function configure(options) {
 		}],
 
 		files: [
-			// @TODO remove me
-			// { pattern: moduleDir('babel-polyfill')+'/dist/polyfill.js', watched: false, included: true, served: true }
+			// Inject Jest matchers:
+			{
+				pattern: path.resolve(__dirname, '../node_modules/expect/build-es5/index.js'),
+				watched: false,
+				included: true,
+				served: true
+			}
 		].concat( ...files.map( pattern => {
 			// Expand '**/xx' patterns but exempt node_modules and gitignored directories
 			let matches = pattern.match(/^\*\*\/(.+)$/);

test/jest-style.test.js

@@ -0,0 +1,9 @@
+describe('jest-style', () => {
+	describe('not.stringContaining', () => {
+		const expected = 'Hello world!';
+
+		it('matches if the received value does not contain the expected substring', () => {
+			expect('How are you?').toEqual(expect.not.stringContaining(expected));
+		});
+	});
+});