replace throws with failures

fix: #7
paulz · May 22, 2022 · b31d59b · b31d59b
1 parent 4e272c9
commit b31d59b
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Showing 4 changed files with 30 additions and 22 deletions.
diff --git a/Example/ApplicationTests/SnapshotTests.swift b/Example/ApplicationTests/SnapshotTests.swift
@@ -5,8 +5,8 @@ import SwiftUI
 
 class SnapshotTests: XCTestCase {
     func testViews() throws {
-        try verifySnapshot(FavoriteView_Previews.self)
-        try verifySnapshot(ContentView())
-        try verifySnapshot(Text("SwiftUI").foregroundColor(.red), "example")
+        verifySnapshot(FavoriteView_Previews.self)
+        verifySnapshot(ContentView())
+        verifySnapshot(Text("SwiftUI").foregroundColor(.red), "example")
     }
 }
diff --git a/README.md b/README.md
@@ -17,8 +17,8 @@ Add Swift Package to a project Test target
 
 See [Example iOS app](https://github.com/paulz/SwiftUI-snapshot-testing/tree/main/Example) project with [SnapshotTests.swift](https://github.com/paulz/SwiftUI-snapshot-testing/blob/main/Example/ApplicationTests/SnapshotTests.swift)
 
-    func testViews() throws {
-        try verifySnapshot(FavoriteView_Previews.self)
-        try verifySnapshot(ContentView())
-        try verifySnapshot(Text("SwiftUI").foregroundColor(.red), "example")
+    func testViews() {
+        verifySnapshot(FavoriteView_Previews.self)
+        verifySnapshot(ContentView())
+        verifySnapshot(Text("SwiftUI").foregroundColor(.red), "example")
     }
diff --git a/Sources/verifySnapshot.swift b/Sources/verifySnapshot.swift
@@ -3,35 +3,40 @@ import SwiftUI
 import UniformTypeIdentifiers
 
 public func verifySnapshot<P>(_ preview: P.Type = P.self, _ name: String? = nil, colorAccuracy: Float = 0.02,
-                              file: StaticString = #filePath, line: UInt = #line) throws where P: PreviewProvider {
+                              file: StaticString = #filePath, line: UInt = #line) where P: PreviewProvider {
     var name = name ?? "\(P.self)"
     let commonPreviewSuffix = "_Previews"
     if name.hasSuffix(commonPreviewSuffix) {
         name.removeLast(commonPreviewSuffix.count)
     }
-    try verifySnapshot(preview.previews, name, colorAccuracy: colorAccuracy, file: file, line: line)
+    verifySnapshot(preview.previews, name, colorAccuracy: colorAccuracy, file: file, line: line)
 }
 
 public func verifySnapshot<V: View>(_ view: V, _ name: String? = nil, colorAccuracy: Float = 0.02,
-                                       file: StaticString = #filePath, line: UInt = #line) throws {
-    let image = try inWindowView(view) {
+                                       file: StaticString = #filePath, line: UInt = #line) {
+    guard let image = try? inWindowView(view, block: {
         $0.renderLayerAsBitmap()
+    }) else {
+        XCTFail("failed to get snapshot of view")
+        return
     }
     let isRunningOnCI = ProcessInfo.processInfo.environment.keys.contains("CI")
     let shouldOverwriteExpected = !isRunningOnCI
-    let pngData = try XCTUnwrap(image.pngData())
+    guard let pngData = image.pngData() else {
+        XCTFail("failed to get image data")
+        return
+    }
     let fileName = (name ?? "\(V.self)") + ".png"
     let url = folderUrl(String(describing: file)).appendingPathComponent(fileName)
-    if let expectedData = try? Data(contentsOf: url) {
-        let expectedImage = try XCTUnwrap(UIImage(data: expectedData))
-        try XCTContext.runActivity(named: "compare images") {
+    if let expectedData = try? Data(contentsOf: url), let expectedImage = UIImage(data: expectedData) {
+        XCTContext.runActivity(named: "compare images") {
             let actualImage = XCTAttachment(data: pngData, uniformTypeIdentifier: UTType.png.identifier)
             actualImage.name = "actual image"
             $0.add(actualImage)
             let diff = compare(image, expectedImage)
             if diff.maxColorDifference() > colorAccuracy {
                 if shouldOverwriteExpected {
-                    try pngData.write(to: url)
+                    XCTAssertNoThrow({try pngData.write(to: url)}, "failed to overwrite snapshot")
                 }
                 XCTFail(
                     """
@@ -44,16 +49,19 @@ public func verifySnapshot<V: View>(_ view: V, _ name: String? = nil, colorAccur
                 )
             }
             let ciImage = diff.difference
-            let diffImage = CIContext().createCGImage(ciImage, from: ciImage.extent)
-            let diffAttachment = XCTAttachment(image: UIImage(cgImage: try XCTUnwrap(diffImage)))
+            guard let diffImage = CIContext().createCGImage(ciImage, from: ciImage.extent) else {
+                XCTFail("failed to get image of difference")
+                return
+            }
+            let diffAttachment = XCTAttachment(image: UIImage(cgImage: diffImage))
             diffAttachment.name = "difference"
             $0.add(diffAttachment)
         }
     } else {
         if shouldOverwriteExpected {
-            try XCTContext.runActivity(named: "recording missing snapshot") {
+            XCTContext.runActivity(named: "recording missing snapshot") {
                 $0.add(.init(data: pngData, uniformTypeIdentifier: UTType.png.identifier))
-                try pngData.write(to: url)
+                XCTAssertNoThrow({try pngData.write(to: url)}, "failed to record snapshot")
             }
             XCTFail("was missing snapshot: \(fileName), now recorded", file: file, line: line)
         } else {

diff --git a/Tests/SampleViewTest.swift b/Tests/SampleViewTest.swift
@@ -6,8 +6,8 @@ import SwiftUI
 class SampleViewTest: XCTestCase {
     let expectedSize = CGSize(width: 30, height: 20)
 
-    func testSwiftUIRendersInWindow() throws {
-        try verifySnapshot(SampleView())
+    func testSwiftUIRendersInWindow() {
+        verifySnapshot(SampleView())
     }
 
     func testImageSizeIsScaledFromExpected() throws {