Merge pull request #40 from Validark/patch-3

(Promise.delay) Allow OnCancel to break out of the current loop

Author: evaera

CHANGELOG.md

@@ -2,7 +2,8 @@
 
 ## [Next]
 ### Fixed
-- Make `Promise.is` work with promises from old versions of the library
+- Make `Promise.is` work with promises from old versions of the library (#41)
+- Make `Promise.delay` properly break out of the current loop (#40)
 
 ## [3.0.0] - 2020-08-17
 ### Changed

lib/init.lua

@@ -719,7 +719,9 @@ do
 			if connection == nil then -- first is nil when connection is nil
 				first = node
 				connection = Promise._timeEvent:Connect(function()
-					while first.endTime <= Promise._getTime() do
+					local threadStart = Promise._getTime()
+
+					while first ~= nil and first.endTime < threadStart do
 						local current = first
 						first = current.next
 
@@ -731,7 +733,6 @@ do
 						end
 
 						current.resolve(Promise._getTime() - current.startTime)
-						if current.next == nil then return end -- kill this thread if there was no `first` before `resolve`
 					end
 				end)
 			else -- first is non-nil

lib/init.spec.lua

@@ -201,6 +201,21 @@ return function()
 			advanceTime(1)
 			expect(promise:getStatus()).to.equal(Promise.Status.Resolved)
 		end)
+
+		it("Should allow for delays to be cancelled", function()
+			local promise = Promise.delay(2)
+
+			Promise.delay(1):andThen(function()
+			    promise:cancel()
+			end)
+
+			expect(promise:getStatus()).to.equal(Promise.Status.Started)
+			advanceTime()
+			expect(promise:getStatus()).to.equal(Promise.Status.Started)
+			advanceTime(1)
+			expect(promise:getStatus()).to.equal(Promise.Status.Cancelled)
+			advanceTime(1)
+		end)
 	end)
 
 	describe("Promise.resolve", function()
@@ -1530,4 +1545,4 @@ return function()
 			expect(Promise.is(oldPromise)).to.equal(true)
 		end)
 	end)
-end
+end