Add support for specifying the UI testing screenshot behavior in a scheme test action (#942)

* Support for specifying UI testing snapshot behavior in scheme test action

* Add tests for new screenshot scheme options

* Update changelog

* Add new fields to Scheme.Test json encoding

* Only save values to JSON if they aren't the defaults

* Using new defaults constants

Author: daltonclaybrook

CHANGELOG.md

@@ -7,6 +7,7 @@
 - Added support for DocC Catalogs [#1091](https://github.com/yonaskolb/XcodeGen/pull/1091) @brevansio
 - Added support for "driver-extension" and "system-extension" product types [#1092](https://github.com/yonaskolb/XcodeGen/issues/1092) @vgorloff
 - Add support for conditionally linking dependencies for specific platforms [#1087](https://github.com/yonaskolb/XcodeGen/pull/1087) @daltonclaybrook
+- Add ability to specify UI testing screenshot behavior in test schemes [#942](https://github.com/yonaskolb/XcodeGen/pull/942) @daltonclaybrook
 
 ### Changed
 - **Breaking**: Rename the `platform` field on `Dependency` to `platformFilter` [#1087](https://github.com/yonaskolb/XcodeGen/pull/1087) @daltonclaybrook

Docs/ProjectSpec.md

@@ -814,6 +814,8 @@ A multiline script can be written using the various YAML multiline methods, for
 - [ ] **coverageTargets**: **[String]** - a list of targets to gather code coverage. Each entry can either be a simple string, or a string using [Project Reference](#project-reference)
 - [ ] **targets**: **[[Test Target](#test-target)]** - a list of targets to test. Each entry can either be a simple string, or a [Test Target](#test-target)
 - [ ] **customLLDBInit**: **String** - the absolute path to the custom `.lldbinit` file
+- [ ] **captureScreenshotsAutomatically**: **Bool** - indicates whether screenshots should be captured automatically while UI Testing. This defaults to true.
+- [ ] **deleteScreenshotsWhenEachTestSucceeds**: **Bool** - whether successful UI tests should cause automatically-captured screenshots to be deleted. If `captureScreenshotsAutomatically` is false, this value is ignored. This defaults to true.
 
 #### Test Target
 - [x] **name**: **String** - The name of the target

Sources/ProjectSpec/Scheme.swift

@@ -164,6 +164,8 @@ public struct Scheme: Equatable {
         public static let gatherCoverageDataDefault = false
         public static let disableMainThreadCheckerDefault = false
         public static let debugEnabledDefault = true
+        public static let captureScreenshotsAutomaticallyDefault = true
+        public static let deleteScreenshotsWhenEachTestSucceedsDefault = true
 
         public var config: String?
         public var gatherCoverageData: Bool
@@ -178,6 +180,8 @@ public struct Scheme: Equatable {
         public var region: String?
         public var debugEnabled: Bool
         public var customLLDBInit: String?
+        public var captureScreenshotsAutomatically: Bool
+        public var deleteScreenshotsWhenEachTestSucceeds: Bool
 
         public struct TestTarget: Equatable, ExpressibleByStringLiteral {
             public static let randomExecutionOrderDefault = false
@@ -236,7 +240,9 @@ public struct Scheme: Equatable {
             language: String? = nil,
             region: String? = nil,
             debugEnabled: Bool = debugEnabledDefault,
-            customLLDBInit: String? = nil
+            customLLDBInit: String? = nil,
+            captureScreenshotsAutomatically: Bool = captureScreenshotsAutomaticallyDefault,
+            deleteScreenshotsWhenEachTestSucceeds: Bool = deleteScreenshotsWhenEachTestSucceedsDefault
         ) {
             self.config = config
             self.gatherCoverageData = gatherCoverageData
@@ -251,6 +257,8 @@ public struct Scheme: Equatable {
             self.region = region
             self.debugEnabled = debugEnabled
             self.customLLDBInit = customLLDBInit
+            self.captureScreenshotsAutomatically = captureScreenshotsAutomatically
+            self.deleteScreenshotsWhenEachTestSucceeds = deleteScreenshotsWhenEachTestSucceeds
         }
 
         public var shouldUseLaunchSchemeArgsEnv: Bool {
@@ -475,6 +483,8 @@ extension Scheme.Test: JSONObjectConvertible {
         region = jsonDictionary.json(atKeyPath: "region")
         debugEnabled = jsonDictionary.json(atKeyPath: "debugEnabled") ?? Scheme.Test.debugEnabledDefault
         customLLDBInit = jsonDictionary.json(atKeyPath: "customLLDBInit")
+        captureScreenshotsAutomatically = jsonDictionary.json(atKeyPath: "captureScreenshotsAutomatically") ?? Scheme.Test.captureScreenshotsAutomaticallyDefault
+        deleteScreenshotsWhenEachTestSucceeds = jsonDictionary.json(atKeyPath: "deleteScreenshotsWhenEachTestSucceeds") ?? Scheme.Test.deleteScreenshotsWhenEachTestSucceedsDefault
     }
 }
 
@@ -508,6 +518,14 @@ extension Scheme.Test: JSONEncodable {
             dict["customLLDBInit"] = customLLDBInit
         }
 
+        if captureScreenshotsAutomatically != Scheme.Test.captureScreenshotsAutomaticallyDefault {
+            dict["captureScreenshotsAutomatically"] = captureScreenshotsAutomatically
+        }
+
+        if deleteScreenshotsWhenEachTestSucceeds != Scheme.Test.deleteScreenshotsWhenEachTestSucceedsDefault {
+            dict["deleteScreenshotsWhenEachTestSucceeds"] = deleteScreenshotsWhenEachTestSucceeds
+        }
+
         return dict
     }
 }

Sources/XcodeGenKit/SchemeGenerator.swift

@@ -228,6 +228,7 @@ public class SchemeGenerator {
             environmentVariables: testVariables,
             language: scheme.test?.language,
             region: scheme.test?.region,
+            systemAttachmentLifetime: scheme.test?.systemAttachmentLifetime,
             customLLDBInitFile: scheme.test?.customLLDBInit
         )
 
@@ -448,3 +449,16 @@ extension PBXProductType {
         }
     }
 }
+
+extension Scheme.Test {
+    var systemAttachmentLifetime: XCScheme.TestAction.AttachmentLifetime? {
+        switch (captureScreenshotsAutomatically, deleteScreenshotsWhenEachTestSucceeds) {
+        case (false, _):
+            return .keepNever
+        case (true, false):
+            return .keepAlways
+        case (true, true):
+            return nil
+        }
+    }
+}

Tests/XcodeGenKitTests/SchemeGeneratorTests.swift

@@ -108,6 +108,7 @@ class SchemeGeneratorTests: XCTestCase {
                 try expect(xcscheme.launchAction?.locationScenarioReference?.identifier) == "New York, NY, USA"
                 try expect(xcscheme.launchAction?.customLLDBInitFile) == "/sample/.lldbinit"
                 try expect(xcscheme.testAction?.customLLDBInitFile) == "/test/.lldbinit"
+                try expect(xcscheme.testAction?.systemAttachmentLifetime).to.beNil()
             }
 
             let frameworkTarget = Scheme.BuildTarget(target: .local(framework.name), buildTypes: [.archiving])
@@ -445,6 +446,42 @@ class SchemeGeneratorTests: XCTestCase {
                 let xcscheme = try unwrap(xcodeProject.sharedData?.schemes.first)
                 try expect(xcscheme.launchAction?.macroExpansion?.buildableName) == "MyApp.app"
             }
+
+            $0.it("generates scheme capturing screenshots automatically and deleting on success") {
+                let xcscheme = try self.makeSnapshotScheme(
+                    buildTarget: buildTarget,
+                    captureScreenshotsAutomatically: true,
+                    deleteScreenshotsWhenEachTestSucceeds: true)
+
+                try expect(xcscheme.testAction?.systemAttachmentLifetime).to.beNil()
+            }
+
+            $0.it("generates scheme capturing screenshots and not deleting") {
+                let xcscheme = try self.makeSnapshotScheme(
+                    buildTarget: buildTarget,
+                    captureScreenshotsAutomatically: true,
+                    deleteScreenshotsWhenEachTestSucceeds: false)
+
+                try expect(xcscheme.testAction?.systemAttachmentLifetime) == .keepAlways
+            }
+
+            $0.it("generates scheme not capturing screenshots") {
+                let xcscheme = try self.makeSnapshotScheme(
+                    buildTarget: buildTarget,
+                    captureScreenshotsAutomatically: false,
+                    deleteScreenshotsWhenEachTestSucceeds: false)
+
+                try expect(xcscheme.testAction?.systemAttachmentLifetime) == .keepNever
+            }
+
+            $0.it("ignores screenshot delete preference when not capturing screenshots") {
+                let xcscheme = try self.makeSnapshotScheme(
+                    buildTarget: buildTarget,
+                    captureScreenshotsAutomatically: false,
+                    deleteScreenshotsWhenEachTestSucceeds: true)
+
+                try expect(xcscheme.testAction?.systemAttachmentLifetime) == .keepNever
+            }
         }
     }
 
@@ -503,4 +540,20 @@ class SchemeGeneratorTests: XCTestCase {
         let xcodeProject = try project.generateXcodeProject()
         return try unwrap(xcodeProject.sharedData?.schemes.first)
     }
+
+    private func makeSnapshotScheme(buildTarget: Scheme.BuildTarget, captureScreenshotsAutomatically: Bool, deleteScreenshotsWhenEachTestSucceeds: Bool) throws -> XCScheme {
+        let scheme = Scheme(
+            name: "MyScheme",
+            build: Scheme.Build(targets: [buildTarget]),
+            run: Scheme.Run(config: "Debug"),
+            test: Scheme.Test(config: "Debug", captureScreenshotsAutomatically: captureScreenshotsAutomatically, deleteScreenshotsWhenEachTestSucceeds: deleteScreenshotsWhenEachTestSucceeds)
+        )
+        let project = Project(
+            name: "test",
+            targets: [app, framework],
+            schemes: [scheme]
+        )
+        let xcodeProject = try project.generateXcodeProject()
+        return try unwrap(xcodeProject.sharedData?.schemes.first)
+    }
 }