Merge pull request #27 from naxxster/fix-merge-subscription

Fix merge operator to produce a subscription.

rx.lua

@@ -1049,6 +1049,8 @@ function Observable:merge(...)
   table.insert(sources, 1, self)
 
   return Observable.create(function(observer)
+    local subscriptions = {}
+
     local function onNext(...)
       return observer:onNext(...)
     end
@@ -1068,8 +1070,14 @@ function Observable:merge(...)
     end
 
     for i = 1, #sources do
-      sources[i]:subscribe(onNext, onError, onCompleted(i))
+      subscriptions[i] = sources[i]:subscribe(onNext, onError, onCompleted(i))
     end
+
+    return Subscription.create(function ()
+      for i = 1, #sources do
+        if subscriptions[i] then subscriptions[i]:unsubscribe() end
+      end
+    end)
   end)
 end
 

src/operators/merge.lua

@@ -9,6 +9,8 @@ function Observable:merge(...)
   table.insert(sources, 1, self)
 
   return Observable.create(function(observer)
+    local subscriptions = {}
+
     local function onNext(...)
       return observer:onNext(...)
     end
@@ -28,7 +30,13 @@ function Observable:merge(...)
     end
 
     for i = 1, #sources do
-      sources[i]:subscribe(onNext, onError, onCompleted(i))
+      subscriptions[i] = sources[i]:subscribe(onNext, onError, onCompleted(i))
     end
+
+    return Subscription.create(function ()
+      for i = 1, #sources do
+        if subscriptions[i] then subscriptions[i]:unsubscribe() end
+      end
+    end)
   end)
 end

tests/merge.lua

@@ -4,6 +4,22 @@ describe('merge', function()
     expect(observable).to.produce(1, 2, 3, 4, 5)
   end)
 
+  it('unsubscribes from all input observables', function()
+    local observableA = Rx.Observable.create(function(observer)
+      return
+    end)
+
+    local unsubscribeB = spy()
+    local subscriptionB = Rx.Subscription.create(unsubscribeB)
+    local observableB = Rx.Observable.create(function(observer)
+      return subscriptionB
+    end)
+
+    local subscription = observableA:merge(observableB):subscribe()
+    subscription:unsubscribe()
+    expect(#unsubscribeB).to.equal(1)
+  end)
+
   it('produces values from all input observables, in order', function()
     local observableA = Rx.Subject.create()
     local observableB = Rx.Subject.create()