utils: Add timeout for waitForEvent method

mono-js · Oct 18, 2017 · 12944a6 · 12944a6
1 parent b1dce49
commit 12944a6
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Showing 2 changed files with 11 additions and 4 deletions.
diff --git a/README.md b/README.md
@@ -115,7 +115,7 @@ Methods:
 - `ok(promise: Object): Promise`
 - `cb(fn: Function, ...args: any[]): Promise`
 - `waitFor(ms: number): Promise`
-- `waitForEvent(emitter: EventEmitter, eventName: string): Promise<Array>`
+- `waitForEvent(emitter: EventEmitter, eventName: string, timeout: number = -1): Promise<Array>`
 - `asyncObject(obj: Object): Promise<Object>`
 
 ## Credits

diff --git a/lib/utils.js b/lib/utils.js
@@ -31,9 +31,16 @@ exports.waitFor = function (ms) {
 /*
 ** waitForEvent(emmiter, eventName)
 */
-exports.waitForEvent = function (emmiter, eventName) {
-	return new Promise((resolve) => {
-		emmiter.once(eventName, (...args) => resolve([...args]))
+exports.waitForEvent = function (emmiter, eventName, timeout = -1) {
+	return new Promise((resolve, reject) => {
+		let resolveCalled = false
+		const r = (...args) => {
+			if (resolveCalled) return
+			resolve(...args)
+			resolveCalled = true
+		}
+		emmiter.once(eventName, (...args) => r([...args]))
+		if (timeout >= 0) setTimeout(() => reject('Timeout'), timeout)
 	})
 }