test: add tests for promises and async/await

see issue #4

package.json

@@ -5,7 +5,7 @@
   "main": "index.js",
   "scripts": {
     "cover": "istanbul cover _mocha index.js -R ./tests --coverage",
-    "test": "mocha ./tests",
+    "test": "mocha ./tests/express-test-harness.js",
     "coveralls": "npm run cover -- --report lcovonly && cat ./coverage/lcov.info | coveralls"
   },
   "repository": {

tests/express-test-harness.js

@@ -83,4 +83,51 @@ describe('express-http-context', function () {
 			done();
 		});
 	});
+
+	it('maintains context when using promises', function (done) {
+		// ARRANGE
+		const app = express();
+
+		app.use(httpContext.middleware);
+
+		const delayWithPromise = delay => new Promise((resolve, reject) => setTimeout(resolve, delay));
+
+		app.get('/test', (req, res) => {
+			const delay = new Number(req.query.delay);
+			const valueFromRequest = req.query.value;
+
+			httpContext.set('value', valueFromRequest);
+
+			delayWithPromise(delay)
+				.then(() => {
+					return delayWithPromise(delay);
+				}).then(() => {
+					const valueFromContext = httpContext.get('value');
+					res.status(200).json({
+						value: valueFromContext
+					});
+				});
+		});
+
+		const sut = supertest(app);
+
+		const value1 = 'value1';
+		const value2 = 'value2';
+
+		// ACT
+		sut.get('/test').query({ delay: 100, value: value1 }).end((err, res) => {
+			// ASSERT
+			assert.equal(res.body.value, value1);
+			done();
+		});
+
+		sut.get('/test').query({ delay: 50, value: value2 }).end((err, res) => {
+			// ASSERT
+			assert.equal(res.body.value, value2);
+		});
+	});
+
+	if (process.versions.node.startsWith('8.')) {
+		require('./node8');
+	}
 });

tests/node8.js

@@ -0,0 +1,46 @@
+'use strict'
+
+const assert = require('chai').assert;
+const express = require('express');
+const supertest = require('supertest');
+const httpContext = require('../index');
+
+it('maintains context when using async/await', function (done) {
+	// ARRANGE
+	const app = express();
+
+	app.use(httpContext.middleware);
+
+	const delayWithPromise = async delay => new Promise((resolve, reject) => setTimeout(resolve, delay));
+
+	app.get('/test', async (req, res) => {
+		const delay = new Number(req.query.delay);
+		const valueFromRequest = req.query.value;
+
+		httpContext.set('value', valueFromRequest);
+
+		await delayWithPromise(delay)
+
+		const valueFromContext = httpContext.get('value');
+		res.status(200).json({
+			value: valueFromContext
+		});
+	});
+
+	const sut = supertest(app);
+
+	const value1 = 'value1';
+	const value2 = 'value2';
+
+	// ACT
+	sut.get('/test').query({ delay: 100, value: value1 }).end((err, res) => {
+		// ASSERT
+		assert.equal(res.body.value, value1);
+		done();
+	});
+
+	sut.get('/test').query({ delay: 50, value: value2 }).end((err, res) => {
+		// ASSERT
+		assert.equal(res.body.value, value2);
+	});
+});