Add Connectable.map to MobiusExtras

Mobius.xcodeproj/project.pbxproj

@@ -7,6 +7,9 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		025BB529244DA65100E80BD2 /* ConnectableMap.swift in Sources */ = {isa = PBXBuildFile; fileRef = 025BB528244DA65100E80BD2 /* ConnectableMap.swift */; };
+		025BB52C244DA6BF00E80BD2 /* ConnectableMapTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 025BB52A244DA68500E80BD2 /* ConnectableMapTests.swift */; };
+		025BB52D244DA6C400E80BD2 /* ConnectableMap.swift in Sources */ = {isa = PBXBuildFile; fileRef = 025BB528244DA65100E80BD2 /* ConnectableMap.swift */; };
 		02BED1BB21DD20D20093FB47 /* ConnectableContramap.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5B9CE80421197FE000DB79A7 /* ConnectableContramap.swift */; };
 		02C4061D2373078400BD7ED8 /* EffectExecutor.swift in Sources */ = {isa = PBXBuildFile; fileRef = 02C4061C2373078400BD7ED8 /* EffectExecutor.swift */; };
 		02C40621237422EF00BD7ED8 /* EffectRouter.swift in Sources */ = {isa = PBXBuildFile; fileRef = 02C40620237422EF00BD7ED8 /* EffectRouter.swift */; };
@@ -292,6 +295,8 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
+		025BB528244DA65100E80BD2 /* ConnectableMap.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ConnectableMap.swift; sourceTree = "<group>"; };
+		025BB52A244DA68500E80BD2 /* ConnectableMapTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ConnectableMapTests.swift; sourceTree = "<group>"; };
 		02C4061C2373078400BD7ED8 /* EffectExecutor.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EffectExecutor.swift; sourceTree = "<group>"; };
 		02C40620237422EF00BD7ED8 /* EffectRouter.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EffectRouter.swift; sourceTree = "<group>"; };
 		02C40622237425E100BD7ED8 /* EffectRouterTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EffectRouterTests.swift; sourceTree = "<group>"; };
@@ -754,6 +759,7 @@
 				5BB287E8209995420043B530 /* SimpleLogger.swift */,
 				DD748322212DB525008EEECD /* Copyable.swift */,
 				5B1F104C21105CAD0067193C /* EventSource+Extensions.swift */,
+				025BB528244DA65100E80BD2 /* ConnectableMap.swift */,
 			);
 			path = Source;
 			sourceTree = "<group>";
@@ -847,6 +853,7 @@
 				5B9CE80621199D4400DB79A7 /* ConnectableContramapTests.swift */,
 				DD748324212DEEC1008EEECD /* CopyableTests.swift */,
 				5B1F104F21105CC00067193C /* EventSource+ExtensionsTests.swift */,
+				025BB52A244DA68500E80BD2 /* ConnectableMapTests.swift */,
 				2DA1E89D2449F1ED00D240B7 /* WikiTutorialTest.swift */,
 			);
 			path = Test;
@@ -1252,6 +1259,7 @@
 				3EE5AF052110BF2E00CF8CA8 /* ConnectableClass.swift in Sources */,
 				2DF4C42420DBDF1B00A4B6DE /* SimpleLogger.swift in Sources */,
 				02BED1BB21DD20D20093FB47 /* ConnectableContramap.swift in Sources */,
+				025BB52D244DA6C400E80BD2 /* ConnectableMap.swift in Sources */,
 				5B1F104E21105CB10067193C /* EventSource+Extensions.swift in Sources */,
 				2D3A696D2355AED90053C95E /* Lock.swift in Sources */,
 			);
@@ -1357,6 +1365,7 @@
 				5B9CE80521197FE000DB79A7 /* ConnectableContramap.swift in Sources */,
 				5B1F104D21105CAD0067193C /* EventSource+Extensions.swift in Sources */,
 				DDA64A6720A0AD2D00150355 /* SimpleLogger.swift in Sources */,
+				025BB529244DA65100E80BD2 /* ConnectableMap.swift in Sources */,
 				5BCF5F0120F3620700721C0D /* ConnectableClass.swift in Sources */,
 				2D3A696E2355AED90053C95E /* Lock.swift in Sources */,
 			);
@@ -1419,6 +1428,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				DD748325212DEEC1008EEECD /* CopyableTests.swift in Sources */,
+				025BB52C244DA6BF00E80BD2 /* ConnectableMapTests.swift in Sources */,
 				5B1F105121105CC50067193C /* EventSource+ExtensionsTests.swift in Sources */,
 				5BCF5F0420F3636800721C0D /* ConnectableClassTests.swift in Sources */,
 				2DA1E8A12449FBC500D240B7 /* WikiTutorialTest.swift in Sources */,

MobiusExtras/Source/ConnectableContramap.swift

@@ -20,22 +20,18 @@
 import MobiusCore
 
 public extension Connectable {
-    func contramap<NewInput>(_ map: @escaping (NewInput) -> Input) -> AnyConnectable<NewInput, Output> {
-        let newConnectClosure = { (consumer: @escaping Consumer<Output>) -> Connection<NewInput> in
-            let connection = self.connect(consumer)
-            let mappedAcceptFunction = { (newTypeInput: NewInput) in
-                let oldTypeInput = map(newTypeInput)
-                connection.accept(oldTypeInput)
-            }
+    /// Transform the input type of this `Connectable` by applying the `transform` function to each input.
+    ///
+    /// - Parameter transform: The function which should be used to transform the input to this `Connectable`
+    /// - Returns: A `Connectable` which applies `transform` to each input value before handling it.
+    func contramap<NewInput>(_ transform: @escaping (NewInput) -> Input) -> AnyConnectable<NewInput, Output> {
+        return AnyConnectable { dispatch in
+            let connection = self.connect(dispatch)
 
-            return Connection<NewInput>(
-                acceptClosure: mappedAcceptFunction,
+            return Connection(
+                acceptClosure: { connection.accept(transform($0)) },
                 disposeClosure: connection.dispose
             )
         }
-
-        let contramapped = AnyConnectable(newConnectClosure)
-
-        return contramapped
     }
 }

MobiusExtras/Source/ConnectableMap.swift

@@ -0,0 +1,35 @@
+// Copyright (c) 2020 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+import MobiusCore
+
+public extension Connectable {
+    /// Transform the output type of this `Connectable` by applying the `transform` function to each output.
+    ///
+    /// - Parameter transform: The function which should be used to transform the output of this `Connectable`
+    /// - Returns: A `Connectable` which applies `transform` to each output value.
+    func map<NewOutput>(_ transform: @escaping (Output) -> NewOutput) -> AnyConnectable<Input, NewOutput> {
+        return AnyConnectable { dispatch in
+            return self.connect { output in
+                let newOutput = transform(output)
+                dispatch(newOutput)
+            }
+        }
+    }
+}

MobiusExtras/Test/ConnectableMapTests.swift

@@ -0,0 +1,68 @@
+// Copyright (c) 2020 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+import MobiusCore
+import MobiusExtras
+import Nimble
+import Quick
+
+class ConnectableMapTests: QuickSpec {
+    override func spec() {
+        context("Connectable Map") {
+            it("applies the `transform` function to the output") {
+                var output: [Int?] = []
+                let connection = TestConnectable()
+                    .map { Int($0) }
+                    .connect {
+                        output.append($0)
+                    }
+
+                connection.accept("1")
+                connection.accept("2")
+                connection.accept("3")
+
+                expect(output).to(equal([1, 2, 3]))
+
+                connection.dispose()
+            }
+
+            it("preserves the connectable's `Disposable` conformance") {
+                let testConnectable = TestConnectable()
+                expect(testConnectable.isDisposed).to(beFalse())
+
+                testConnectable
+                    .connect { _ in }
+                    .dispose()
+
+                expect(testConnectable.isDisposed).to(beTrue())
+            }
+        }
+    }
+}
+
+private final class TestConnectable: Connectable {
+    var isDisposed = false
+
+    func connect(_ consumer: @escaping Consumer<String>) -> Connection<String> {
+        return Connection(
+            acceptClosure: consumer,
+            disposeClosure: { self.isDisposed = true }
+        )
+    }
+}