support promise return in ospec

docs/change-log.md

@@ -23,6 +23,11 @@
 
 - API: Introduction of `m.redraw.sync()` ([#1592](https://github.com/MithrilJS/mithril.js/pull/1592))
 
+#### Ospec improvements:
+
+- Added support for async functions and promises in tests - ([#1928](https://github.com/MithrilJS/mithril.js/pull/1928))
+- Error handling for async tests with `done` callbacks supports error as first argument
+
 #### Bug fixes
 
 - API: `m.route.set()` causes all mount points to be redrawn ([#1592](https://github.com/MithrilJS/mithril.js/pull/1592))

ospec/README.md

@@ -148,6 +148,22 @@ o("setTimeout calls callback", function(done) {
 })
 ```
 
+Alternativly you can return a promise or even use an async function in tests:
+
+```javascript
+o("promise test", function() {
+	return new Promise(function(resolve) {
+		setTimeout(resolve, 10)
+	})
+})
+```
+
+```javascript
+o("promise test", async function() {
+	await someOtherAsyncFunction()
+})
+```
+
 By default, asynchronous tests time out after 20ms. This can be changed on a per-test basis using the `timeout` argument:
 
 ```javascript
@@ -158,7 +174,22 @@ o("setTimeout calls callback", function(done, timeout) {
 })
 ```
 
-Note that the `timeout` function call must be the first statement in its test.
+Note that the `timeout` function call must be the first statement in its test.	This currently does not work for promise tests. You can combine both methods to do this:
+
+```javascript
+o("promise test", function(done, timeout) {
+	timeout(1000)
+	someOtherAsyncFunctionThatTakes900ms().then(done)
+})
+```
+
+```javascript
+o("promise test", async function(done, timeout) {
+	timeout(1000)
+	await someOtherAsyncFunctionThatTakes900ms()
+	done()
+})
+```
 
 Asynchronous tests generate an assertion that succeeds upon calling `done` or fails on timeout with the error message `async test timed out`.
 

ospec/ospec.js

@@ -84,40 +84,56 @@ module.exports = new function init(name) {
 				if (cursor === fns.length) return
 
 				var fn = fns[cursor++]
+				var timeout = 0, delay = 200, s = new Date
+				var isDone = false
+
+				function done(err) {
+					if (err) {
+						if (err.message) record(err.message, err)
+						else record(err)
+						subjects.pop()
+						next()
+					}
+					if (timeout !== undefined) {
+						timeout = clearTimeout(timeout)
+						if (delay !== Infinity) record(null)
+						if (!isDone) next()
+						else throw new Error("`" + arg + "()` should only be called once")
+						isDone = true
+					}
+					else console.log("# elapsed: " + Math.round(new Date - s) + "ms, expected under " + delay + "ms")
+				}
+
+				function startTimer() {
+					timeout = setTimeout(function() {
+						timeout = undefined
+						record("async test timed out")
+						next()
+					}, Math.min(delay, 2147483647))
+				}
+
 				if (fn.length > 0) {
-					var timeout = 0, delay = 200, s = new Date
-					var isDone = false
 					var body = fn.toString()
 					var arg = (body.match(/\(([\w$]+)/) || body.match(/([\w$]+)\s*=>/) || []).pop()
 					if (body.indexOf(arg) === body.lastIndexOf(arg)) throw new Error("`" + arg + "()` should be called at least once")
 					try {
-						fn(function done() {
-							if (timeout !== undefined) {
-								timeout = clearTimeout(timeout)
-								if (delay !== Infinity) record(null)
-								if (!isDone) next()
-								else throw new Error("`" + arg + "()` should only be called once")
-								isDone = true
-							}
-							else console.log("# elapsed: " + Math.round(new Date - s) + "ms, expected under " + delay + "ms")
-						}, function(t) {delay = t})
+						fn(done, function(t) {delay = t})
 					}
 					catch (e) {
-						record(e.message, e)
-						subjects.pop()
-						next()
+						done(e)
 					}
 					if (timeout === 0) {
-						timeout = setTimeout(function() {
-							timeout = undefined
-							record("async test timed out")
-							next()
-						}, Math.min(delay, 2147483647))
+						startTimer()
 					}
 				}
 				else {
-					fn()
-					nextTickish(next)
+					var p = fn()
+					if (p && p.then) {
+						startTimer()
+						p.then(function() { done() }, done)
+					} else {
+						nextTickish(next)
+					}
 				}
 			}
 		}

ospec/tests/test-ospec.js

@@ -107,7 +107,7 @@ o.spec("ospec", function() {
 			o(output).deepEquals({tag: "div", children: children})
 		})
 	})
-	o.spec("async", function() {
+	o.spec("async callback", function() {
 		var a = 0, b = 0
 
 		o.before(function(done) {
@@ -148,4 +148,51 @@ o.spec("ospec", function() {
 			})
 		})
 	})
+
+	o.spec("async promise", function() {
+		var a = 0, b = 0
+
+		function wrapPromise(fn) {
+			return new Promise((resolve, reject) => {
+				callAsync(() => {
+					try {
+						fn()
+						resolve()
+					} catch(e) {
+						reject(e)
+					}
+				})
+			})
+		}
+
+		o.before(function() {
+			return wrapPromise(() => {
+				a = 1
+			})
+		})
+
+		o.after(function() {
+			return wrapPromise(function() {
+				a = 0
+			})
+		})
+
+		o.beforeEach(function() {
+			return wrapPromise(function() {
+				b = 1
+			})
+		})
+		o.afterEach(function() {
+			return wrapPromise(function() {
+				b = 0
+			})
+		})
+
+		o("promise functions", async function() {
+			await wrapPromise(function() {
+				o(a).equals(b)
+				o(a).equals(1)("a and b should be initialized")
+			})
+		})
+	})
 })

promise/tests/test-promise.js

@@ -131,7 +131,7 @@ o.spec("promise", function() {
 				callAsync(function() {resolve(promise)})
 			})
 
-			promise.then(null, done)
+			promise.then(null, () => done())
 		})
 		o("non-function onFulfilled is ignored", function(done) {
 			var promise = Promise.resolve(1)