Add delay.reject

index.js

@@ -18,3 +18,12 @@ module.exports = function (ms) {
 
 	return thunk;
 };
+
+module.exports.reject = function (ms, value) {
+	if (arguments.length === 1) {
+		return new Promise(function (resolve, reject) {
+			setTimeout(reject.bind(null, value), ms);
+		});
+	}
+	return module.exports.reject.bind(null, ms);
+};

test.js

@@ -4,14 +4,41 @@ import inRange from 'in-range';
 import fn from './';
 
 test('promise', async t => {
+	t.plan(1);
 	const end = timeSpan();
 	await fn(50);
-	t.true(inRange(end(), 30, 70));
+	t.true(inRange(end(), 30, 70), 'should be delayed');
 });
 
 test('thunk', async t => {
+	t.plan(2);
 	const end = timeSpan();
 	const result = await Promise.resolve('foo').then(fn(50));
-	t.true(inRange(end(), 30, 70));
-	t.is(result, 'foo');
+	t.true(inRange(end(), 30, 70), 'should be delayed');
+	t.is(result, 'foo', 'should pass through the value');
+});
+
+test.cb('.reject with two arguments', t => {
+	t.plan(2);
+	const error = new Error('foo');
+	const end = timeSpan();
+	fn.reject(50, error)
+		.catch(err => {
+			t.true(inRange(end(), 30, 70), 'should be delayed');
+			t.is(err, error, 'promise should be rejected with the second argument');
+			t.end();
+		});
+});
+
+test.cb('.reject with one argument (thunk)', t => {
+	t.plan(2);
+	const val = 'foo';
+	const end = timeSpan();
+	Promise.resolve(val)
+		.then(fn.reject(50))
+		.catch(err => {
+			t.true(inRange(end(), 30, 70), 'should be delayed');
+			t.is(err, val, 'promise should be rejected with the resolved value');
+			t.end();
+		});
 });