Add module aliasing fixtures and functional tests

Fixtures/Miscellaneous/ModuleAliasing/Simple/appPkg/Package.swift

@@ -0,0 +1,32 @@
+// swift-tools-version:999.0
+import PackageDescription
+
+let package = Package(
+    name: "appPkg",
+    platforms: [
+        .macOS(.v10_12),
+        .iOS(.v10),
+        .tvOS(.v11),
+        .watchOS(.v5)
+    ],
+    dependencies: [
+        .package(url: "../gamePkg", from: "1.0.0"),
+    ],
+    targets: [
+        .executableTarget(
+            name: "App",
+            dependencies: [
+                "Utils",
+                .product(name: "Utils",
+                         package: "gamePkg",
+                         moduleAliases: ["Utils": "GameUtils"])
+            ],
+            path: "./Sources/App"),
+        .target(
+                name: "Utils",
+                dependencies: [],
+                path: "./Sources/Utils"
+            )
+        ]
+    )
+

Fixtures/Miscellaneous/ModuleAliasing/Simple/appPkg/Sources/App/main.swift

@@ -0,0 +1,17 @@
+/*
+ This source file is part of the Swift.org open source project
+
+ Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+ Licensed under Apache License v2.0 with Runtime Library Exception
+
+ See http://swift.org/LICENSE.txt for license information
+ See http://swift.org/CONTRIBUTORS.txt for Swift project authors
+*/
+
+import Utils
+import GameUtils
+
+Utils.echoModule()
+
+let level = LevelDetector.detect(for: "TestUser")
+print(level)

Fixtures/Miscellaneous/ModuleAliasing/Simple/appPkg/Sources/Utils/FileUtils.swift

@@ -0,0 +1,13 @@
+/*
+ This source file is part of the Swift.org open source project
+
+ Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+ Licensed under Apache License v2.0 with Runtime Library Exception
+
+ See http://swift.org/LICENSE.txt for license information
+ See http://swift.org/CONTRIBUTORS.txt for Swift project authors
+*/
+
+public func echoModule() {
+    print("Utils")
+}

Fixtures/Miscellaneous/ModuleAliasing/Simple/gamePkg/Package.swift

@@ -0,0 +1,14 @@
+// swift-tools-version:4.2
+import PackageDescription
+
+let package = Package(
+    name: "gamePkg",
+    products: [
+        .library(name: "Game", targets: ["Game"]),
+        .library(name: "Utils", targets: ["Utils"]),
+    ],
+    targets: [
+        .target(name: "Game", dependencies: ["Utils"]),
+        .target(name: "Utils", dependencies: []),
+    ]
+)

Fixtures/Miscellaneous/ModuleAliasing/Simple/gamePkg/Sources/Game/FileGame.swift

@@ -0,0 +1,22 @@
+/*
+ This source file is part of the Swift.org open source project
+
+ Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+ Licensed under Apache License v2.0 with Runtime Library Exception
+
+ See http://swift.org/LICENSE.txt for license information
+ See http://swift.org/CONTRIBUTORS.txt for Swift project authors
+*/
+
+import Utils
+
+public struct Game: Equatable {
+    public var levels: [LevelDetector]
+
+    public static func startGame(for user: String) -> Int {
+        if user.isEmpty {
+            return -1
+        }
+        return LevelDetector.detect(for: user)
+    }
+}

Fixtures/Miscellaneous/ModuleAliasing/Simple/gamePkg/Sources/Utils/FileUtils.swift

@@ -0,0 +1,15 @@
+/*
+ This source file is part of the Swift.org open source project
+
+ Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+ Licensed under Apache License v2.0 with Runtime Library Exception
+
+ See http://swift.org/LICENSE.txt for license information
+ See http://swift.org/CONTRIBUTORS.txt for Swift project authors
+*/
+
+public struct LevelDetector: Equatable {
+    public static func detect(for user: String) -> Int {
+        return user.count
+    }
+}

Tests/FunctionalTests/DependencyResolutionTests.swift

@@ -15,7 +15,7 @@ import SPMTestSupport
 import TSCBasic
 import Workspace
 import XCTest
-
+ 
 class DependencyResolutionTests: XCTestCase {
     func testInternalSimple() {
         fixture(name: "DependencyResolution/Internal/Simple") { prefix in

Tests/FunctionalTests/ModuleAliasingTests.swift

@@ -0,0 +1,32 @@
+/*
+ This source file is part of the Swift.org open source project
+
+ Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+ Licensed under Apache License v2.0 with Runtime Library Exception
+
+ See http://swift.org/LICENSE.txt for license information
+ See http://swift.org/CONTRIBUTORS.txt for Swift project authors
+*/
+
+import Commands
+import PackageModel
+import SourceControl
+import SPMTestSupport
+import TSCBasic
+import Workspace
+import XCTest
+
+class ModuleAliasingTests: XCTestCase {
+
+    func testExternalSimple() {
+        fixture(name: "Miscellaneous/ModuleAliasing/Simple") { prefix in
+            let app = prefix.appending(components: "appPkg")
+            XCTAssertBuilds(app)
+            XCTAssertFileExists(prefix.appending(components: "appPkg", ".build", UserToolchain.default.triple.platformBuildPathComponent(), "debug", "App"))
+            XCTAssertFileExists(prefix.appending(components: "appPkg", ".build", UserToolchain.default.triple.platformBuildPathComponent(), "debug", "GameUtils.swiftmodule"))
+            XCTAssertFileExists(prefix.appending(components: "appPkg", ".build", UserToolchain.default.triple.platformBuildPathComponent(), "debug", "Utils.swiftmodule"))
+            let result = try SwiftPMProduct.SwiftBuild.executeProcess([], packagePath: app)
+            XCTAssertEqual(result.exitStatus, .terminated(code: 0))
+        }
+    }
+}