Add support for installing Stagehand via SPM (#15)

* Adds support for installing Stagehand via Swift Package Manager
* Adds scripts for running builds on CI
* Updates directory structure to recommended SPM structure
* Updates installation instructions in README

This resolves part of #2, since it only supports Stagehand and not StagehandTesting.

.gitignore

@@ -30,3 +30,8 @@ Pods/
 
 # Swift Playgrounds
 timeline.xctimeline
+
+# Swift Pacakge Manager
+generated/
+.build/
+.swiftpm/

.travis.yml

@@ -1,19 +1,20 @@
 language: objective-c
 jobs:
   - osx_image: xcode11.3
-    env: DEST='platform=iOS Simulator,OS=13.3,name=iPhone 11 Pro'
+    env: ACTIONS="xcode,pod-lint";PLATFORM="iOS_13"
   - osx_image: xcode10.3
-    env: DEST='platform=iOS Simulator,OS=12.4,name=iPhone Xs'
+    env: ACTIONS="xcode,pod-lint";PLATFORM="iOS_12"
   - osx_image: xcode10.3
-    env: DEST='platform=iOS Simulator,OS=11.4,name=iPhone X'
+    env: ACTIONS="xcode,pod-lint";PLATFORM="iOS_11"
   - osx_image: xcode10.3
-    env: DEST='platform=iOS Simulator,OS=10.3.1,name=iPhone 7'
+    env: ACTIONS="xcode,pod-lint";PLATFORM="iOS_10"
+  - osx_image: xcode11.3
+    env: ACTIONS="spm";PLATFORM="iOS_13"
 install:
   - bundle install --gemfile=Example/Gemfile
   - bundle exec --gemfile=Example/Gemfile pod install --project-directory=Example
 script:
-  - set -o pipefail && xcodebuild test -enableCodeCoverage YES -workspace Example/Stagehand.xcworkspace -scheme "Stagehand Demo App" -sdk iphonesimulator -destination "$DEST" ONLY_ACTIVE_ARCH=NO | xcpretty
-  - bundle exec --gemfile=Example/Gemfile pod lib lint
+  - ./Scripts/ci.sh
 branches:
   only:
   - master

Example/Podfile.lock

@@ -25,8 +25,8 @@ EXTERNAL SOURCES:
 
 SPEC CHECKSUMS:
   iOSSnapshotTestCase: 9ab44cb5aa62b84d31847f40680112e15ec579a6
-  Stagehand: a4a339d2b1227bbffadd18877b2ae28cec416b1f
-  StagehandTesting: 410114f4d7583665f5e8498de1e4d631b0f49997
+  Stagehand: 6d360781f1e1ad7c15a16253952164c0035010d1
+  StagehandTesting: 941f1f1e381cf27e91a677895e249a3078e863e9
 
 PODFILE CHECKSUM: e2058eb578e4d6fb432b015c43b4e221c1b70e87
 

Package.swift

@@ -0,0 +1,42 @@
+// swift-tools-version:5.0.1
+
+//
+//  Copyright 2020 Square Inc.
+//
+//  Licensed 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 PackageDescription
+
+let package = Package(
+	name: "Stagehand",
+	platforms: [
+		.iOS(.v10),
+	],
+	products: [
+		.library(
+			name: "Stagehand",
+			targets: ["Stagehand"]
+		),
+	],
+	targets: [
+		.target(
+			name: "Stagehand",
+			dependencies: [],
+			path: "Sources/Stagehand"
+		),
+	],
+	swiftLanguageVersions: [.v5]
+)
+
+let version = Version(2, 0, 3)

README.md

@@ -14,12 +14,30 @@ Stagehand provides a modern, type-safe API for building animations on iOS. Stage
 
 ## Installation
 
-Stagehand is available through [CocoaPods](https://cocoapods.org). To install it, simply add the following line to your Podfile:
+### CocoaPods
+
+To install Stagehand via [CocoaPods](https://cocoapods.org), simply add the following line to your `Podfile`:
 
 ```ruby
 pod 'Stagehand'
 ```
 
+To install StagehandTesting, the animation snapshot testing utilities, add the following line to your test target definition in your `Podfile`:
+
+```ruby
+pod 'StagehandTesting'
+```
+
+### Swift Package Manager
+
+To install Stagehand via [Swift Package Manager](https://github.com/apple/swift-package-manager), add the following to your `Package.swift`:
+
+```swift
+dependencies: [
+    .package(url: "https://github.com/cashapp/stagehand", from: "2.0.3"),
+],
+```
+
 ## Getting Started with Stagehand
 
 An animation begins with the construction of an `Animation`. An `Animation` is generic over a type of element and acts as a definition of how that element should be animated.

Scripts/build.swift

@@ -0,0 +1,182 @@
+#!/usr/bin/env swift
+
+import Foundation
+
+// Usage: build.swift <spm|xcode> <platform> [<path_to_xcpretty>]
+
+func execute(commandPath: String, arguments: [String], pipedTo pipeProcess: Process? = nil) throws {
+	let task = Process()
+	task.launchPath = commandPath
+	task.arguments = arguments
+
+	let argumentsString = arguments
+		.map { argument in
+			if argument.contains(" ") {
+				return "\"\(argument)\""
+			} else {
+				return argument
+			}
+		}
+		.joined(separator: " ")
+
+	if let pipeProcess = pipeProcess, let pipePath = pipeProcess.launchPath {
+		let pipe = Pipe()
+		task.standardOutput = pipe
+		pipeProcess.standardInput = pipe
+
+		print("Launching command: \(commandPath) \(argumentsString) | \(pipePath)")
+
+	} else {
+		print("Launching command: \(commandPath) \(argumentsString)")
+	}
+
+	task.launch()
+
+	pipeProcess?.launch()
+
+	task.waitUntilExit()
+
+	guard task.terminationStatus == 0 else {
+		throw TaskError.code(task.terminationStatus)
+	}
+}
+
+enum TaskError: Error {
+	case code(Int32)
+}
+
+enum Platform: String, CustomStringConvertible {
+	case iOS_13
+	case iOS_12
+	case iOS_11
+	case iOS_10
+
+	var destination: String {
+		switch self {
+		case .iOS_13:
+			return "platform=iOS Simulator,OS=13.3,name=iPhone 11 Pro"
+		case .iOS_12:
+			return "platform=iOS Simulator,OS=12.4,name=iPhone Xs"
+		case .iOS_11:
+			return "platform=iOS Simulator,OS=11.4,name=iPhone X"
+		case .iOS_10:
+			return "platform=iOS Simulator,OS=10.3.1,name=iPhone 7"
+		}
+	}
+
+	var description: String {
+		return rawValue
+	}
+}
+
+enum Task: String, CustomStringConvertible {
+	case spm
+	case xcode
+
+	var workspace: String? {
+		switch self {
+		case .xcode:
+			return "Example/Stagehand.xcworkspace"
+		case .spm:
+			return nil
+		}
+	}
+
+	var project: String? {
+		switch self {
+		case .spm:
+			return "generated/Stagehand.xcodeproj"
+		case .xcode:
+			return nil
+		}
+	}
+
+	var scheme: String {
+		switch self {
+		case .xcode:
+			return "Stagehand Demo App"
+		case .spm:
+			return "Stagehand-Package"
+		}
+	}
+
+	var shouldGenerateXcodeProject: Bool {
+		switch self {
+		case .spm:
+			return true
+		case .xcode:
+			return false
+		}
+	}
+
+	var shouldRunTests: Bool {
+		switch self {
+		case .spm:
+			return false
+		case .xcode:
+			return true
+		}
+	}
+
+	var description: String {
+		return rawValue
+	}
+}
+
+guard CommandLine.arguments.count > 2 else {
+	print("Usage: build.swift [spm|xcode] <platform>")
+	throw TaskError.code(1)
+}
+
+let rawTask = CommandLine.arguments[1]
+let rawPlatform = CommandLine.arguments[2]
+
+guard let task = Task(rawValue: rawTask) else {
+	print("Received unknown task \"\(rawTask)\"")
+	throw TaskError.code(1)
+}
+
+if task.shouldGenerateXcodeProject {
+	try execute(commandPath: "/usr/bin/swift", arguments: ["package", "generate-xcodeproj", "--output=generated/"])
+}
+
+guard let platform = Platform(rawValue: rawPlatform) else {
+	print("Received unknown platform \"\(rawPlatform)\"")
+	throw TaskError.code(1)
+}
+
+var xcodeBuildArguments: [String] = []
+
+if let workspace = task.workspace {
+	xcodeBuildArguments.append("-workspace")
+	xcodeBuildArguments.append(workspace)
+} else if let project = task.project {
+	xcodeBuildArguments.append("-project")
+	xcodeBuildArguments.append(project)
+}
+
+xcodeBuildArguments.append(
+	contentsOf: [
+		"-scheme", task.scheme,
+		"-sdk", "iphonesimulator",
+		"-PBXBuildsContinueAfterErrors=0",
+		"-destination", platform.destination,
+		"ONLY_ACTIVE_ARCH=NO",
+	]
+)
+
+xcodeBuildArguments.append("build")
+
+if task.shouldRunTests {
+	xcodeBuildArguments.append("test")
+}
+
+let xcpretty: Process?
+if CommandLine.arguments.count > 3 {
+	xcpretty = .init()
+	xcpretty?.launchPath = CommandLine.arguments[3]
+} else {
+	xcpretty = nil
+}
+
+try execute(commandPath: "/usr/bin/xcodebuild", arguments: xcodeBuildArguments, pipedTo: xcpretty)

Scripts/ci.sh

@@ -0,0 +1,22 @@
+#!/bin/bash -l
+set -e
+
+# Find the directory in which this script resides.
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+actionstr=$(echo $ACTIONS | tr "," "\n")
+for action in $actionstr ; do
+	case $action in
+	xcode)
+		$DIR/build.swift xcode $PLATFORM `which xcpretty`
+		;;
+
+	spm)
+		$DIR/build.swift spm $PLATFORM
+		;;
+
+	pod-lint)
+		bundle exec --gemfile=Example/Gemfile pod lib lint --verbose --fail-fast
+		;;
+	esac
+done

Stagehand/Classes/Core/Driver/DisplayLinkDriver.swift → Sources/Stagehand/Driver/DisplayLinkDriver.swift

@@ -14,7 +14,7 @@
 //  limitations under the License.
 //
 
-import Foundation
+import QuartzCore
 
 /// An animation driver that is controlled by a `CADisplayLink`. This driver is intended for use with non-interactive
 /// animations that have a specified duration.

Stagehand.podspec

@@ -11,7 +11,7 @@ Pod::Spec.new do |s|
 
   s.swift_version = '5.0.1'
 
-  s.source_files = 'Stagehand/Classes/Core/**/*'
+  s.source_files = 'Sources/Stagehand/**/*'
 
   s.frameworks = 'CoreGraphics', 'UIKit'
 

StagehandTesting.podspec

@@ -11,7 +11,7 @@ Pod::Spec.new do |s|
 
   s.swift_version = '5.0.1'
 
-  s.source_files = 'Stagehand/Classes/Testing/**/*'
+  s.source_files = 'Sources/StagehandTesting/**/*'
 
   # The dependency on Stagehand is pinned to the same version as StagehandTesting. This is because
   # StagehandTesting depends on internal methods inside Stagehand, so the normal rules of semantic