Cleaned up and added some additional unit tests

Reviewers: O4 Material Motion Apple platform reviewers, O2 Material Motion, markwei

Reviewed By: O4 Material Motion Apple platform reviewers, O2 Material Motion, markwei

Tags: #material_motion

Differential Revision: http://codereview.cc/D2100

tests/unit/MemoryLeakTests.swift

@@ -63,9 +63,9 @@ class MemoryLeakTests: XCTestCase {
     weak var weakObservable = observable
 
     autoreleasepool {
-      let _ = observable!.subscribe(next: {
+      let _ = observable!.subscribe {
         let _ = $0
-      })
+      }
       // Remove our only strong reference.
       observable = nil
     }
@@ -85,9 +85,9 @@ class MemoryLeakTests: XCTestCase {
     autoreleasepool {
       let _ = observable!.map { value in
         return value * value
-        }.subscribe(next: {
+        }.subscribe {
           let _ = $0
-        })
+        }
       // Remove our only strong reference.
       observable = nil
     }
@@ -108,9 +108,9 @@ class MemoryLeakTests: XCTestCase {
 
       let subscription = observable!.map { value in
         return value * value
-        }.subscribe(next: {
+        }.subscribe {
           let _ = $0
-        })
+        }
       // Remove our only strong reference.
       subscription.unsubscribe()
     }

tests/unit/ObservableTests.swift

@@ -38,6 +38,37 @@ class ObservableTests: XCTestCase {
     waitForExpectations(timeout: 0)
   }
 
+  func testUnsubscribesOnDeallocation() {
+    var didUnsubscribe = false
+
+    autoreleasepool {
+      let observable = IndefiniteObservable<CGFloat> { observer in
+        return {
+          didUnsubscribe = true
+        }
+      }
+
+      let _ = observable.subscribe { _ in }
+    }
+
+    XCTAssertTrue(didUnsubscribe)
+  }
+
+  func testUnsubscribesOnUnsubscribe() {
+    var didUnsubscribe = false
+
+    let observable = IndefiniteObservable<CGFloat> { observer in
+      return {
+        didUnsubscribe = true
+      }
+    }
+
+    let subscription = observable.subscribe { _ in }
+    subscription.unsubscribe()
+
+    XCTAssertTrue(didUnsubscribe)
+  }
+
   func testTwoSubsequentSubscriptions() {
     let value = 10
 

tests/unit/SimpleOperators.swift

@@ -20,6 +20,8 @@ import IndefiniteObservable
 // Simple operators used by the tests.
 
 extension IndefiniteObservable {
+
+  // Map from one value type to another.
   public func map<U>(_ transform: @escaping (T) -> U) -> IndefiniteObservable<U> {
     return IndefiniteObservable<U> { observer in
       return self.subscribe {
@@ -28,10 +30,11 @@ extension IndefiniteObservable {
     }
   }
 
-  public func filter(_ isIncluded: @escaping (T) -> Bool) -> IndefiniteObservable<T> {
+  // Only emit values downstream for which passesTest returns true
+  public func filter(_ passesTest: @escaping (T) -> Bool) -> IndefiniteObservable<T> {
     return IndefiniteObservable<T> { observer in
       return self.subscribe {
-        if isIncluded($0) {
+        if passesTest($0) {
           observer.next($0)
         }
       }.unsubscribe