Merge pull request #41 from StrangePan/issue-40

Fix zip operators not returning a subscription, issue #40

rx.lua

@@ -1813,6 +1813,7 @@ function Observable.zip(...)
   return Observable.create(function(observer)
     local values = {}
     local active = {}
+    local subscriptions = {}
     for i = 1, count do
       values[i] = {n = 0}
       active[i] = true
@@ -1858,8 +1859,14 @@ function Observable.zip(...)
     end
 
     for i = 1, count do
-      sources[i]:subscribe(onNext(i), onError, onCompleted(i))
+      subscriptions[i] = sources[i]:subscribe(onNext(i), onError, onCompleted(i))
     end
+
+    return Subscription.create(function()
+      for i = 1, count do
+        if subscriptions[i] then subscriptions[i]:unsubscribe() end
+      end
+    end)
   end)
 end
 

src/operators/zip.lua

@@ -15,6 +15,7 @@ function Observable.zip(...)
   return Observable.create(function(observer)
     local values = {}
     local active = {}
+    local subscriptions = {}
     for i = 1, count do
       values[i] = {n = 0}
       active[i] = true
@@ -60,7 +61,13 @@ function Observable.zip(...)
     end
 
     for i = 1, count do
-      sources[i]:subscribe(onNext(i), onError, onCompleted(i))
+      subscriptions[i] = sources[i]:subscribe(onNext(i), onError, onCompleted(i))
     end
+
+    return Subscription.create(function()
+      for i = 1, count do
+        if subscriptions[i] then subscriptions[i]:unsubscribe() end
+      end
+    end)
   end)
 end

tests/zip.lua

@@ -3,6 +3,25 @@ describe('zip', function()
     expect(Rx.Observable.fromRange(1, 5):zip()).to.produce(1, 2, 3, 4, 5)
   end)
 
+  it('unsubscribes from all input observables', function()
+    local unsubscribeA = spy()
+    local subscriptionA = Rx.Subscription.create(unsubscribeA)
+    local observableA = Rx.Observable.create(function(observer)
+      return subscriptionA
+    end)
+
+    local unsubscribeB = spy()
+    local subscriptionB = Rx.Subscription.create(unsubscribeB)
+    local observableB = Rx.Observable.create(function(observer)
+      return subscriptionB
+    end)
+
+    local subscription = Rx.Observable.zip(observableA, observableB):subscribe()
+    subscription:unsubscribe()
+    expect(#unsubscribeA).to.equal(1)
+    expect(#unsubscribeB).to.equal(1)
+  end)
+
   it('groups values produced by the sources by their index', function()
     local observableA = Rx.Observable.fromRange(1, 3)
     local observableB = Rx.Observable.fromRange(2, 4)