Merge pull request #153 from cashapp/entin/extract-images-script

Add script for extracting snapshot images from test results

Author: NickEntin

Scripts/ExtractImagesFromTestResults.swift

@@ -0,0 +1,84 @@
+#!/usr/bin/swift
+
+// Usage:
+//
+// 1. Download the Test Results bundle from the CI build. From your PR, go to
+//    Checks > CI, then click on "Test Results" in the Artifacts section.
+//
+// 2. Run this script with the path to this download.
+//
+//		./Scripts/ExtractImagesFromTestResults.sh /path/to/Test\ Results
+//
+// 3. This will create a directory called "tmp" that contains all of the
+//    extracted images (reference, failed, and diff) organized by OS version,
+//	 test class name, and test name.
+
+import Foundation
+
+enum TaskError: Error {
+	case code(Int32)
+}
+
+func execute(commandPath: String, arguments: [String]) throws {
+	let task = Process()
+	task.launchPath = commandPath
+	task.arguments = arguments
+
+	task.launch()
+
+	task.waitUntilExit()
+
+	guard task.terminationStatus == 0 else {
+		throw TaskError.code(task.terminationStatus)
+	}
+}
+
+if CommandLine.arguments.count < 2 || CommandLine.arguments[1] == "--help" || CommandLine.arguments[1] == "-h" {
+	print("usage: CompareRenamedSnapshots SNAPSHOT_LIST_FILE OLD_REPO_PATH NEW_DEVICE_ID OLD_DEVICE_ID")
+	exit(0)
+}
+
+let testResultsContainerPath = CommandLine.arguments[1]
+let testResultsContainerURL = URL(filePath: testResultsContainerPath)
+
+let fileManager = FileManager.default
+guard let testResultsEnumerator = fileManager.enumerator(at: testResultsContainerURL, includingPropertiesForKeys: [URLResourceKey.nameKey], options: .skipsHiddenFiles) else {
+    exit(1)
+}
+
+func parseResults(testResultsPath: String, outputPath: String) throws {
+	try execute(
+		commandPath: "/opt/homebrew/bin/xcparse",
+		arguments: ["screenshots", "--os", "--test", testResultsPath, outputPath]
+	)
+}
+
+for case let fileURL as URL in testResultsEnumerator {
+    if fileURL.path.hasSuffix(".xcresult") {
+    	try parseResults(testResultsPath: fileURL.path, outputPath: "tmp")
+    }
+}
+
+/*
+
+As a future enhancement, this script could also rename the failed snapshot images. One complicating
+factor of this is the tests with multiple associated reference images (e.g. when using identifiers)
+don't differentiate the resulting images in the test result bundle. We'll also need to handle
+renaming based on which snapshot engine was used:
+
+	FBSnapshotTestCase
+
+		/Example/SnapshotTests/ReferenceImages/_64/<TestClass>/
+
+			<TestName>[email protected]
+			<TestName>[email protected]
+
+	SnapshotTesting
+
+		/Example/SnapshotTests/__Snapshots__/<TestClass>/
+
+			<TestName>.390x844-14-5-3x.png
+			<TestName>.375x812-13-7-3x.png
+
+*/
+