Merge branch 'master' into rtl_support_with_test_plans

Author: SebastianOsinski

README.md

@@ -145,6 +145,15 @@ dependencies: [
 ]
 ```
 
+Next, add `SnapshotTesting` as a dependency of your test target:
+
+```swift
+targets: [
+  .target(name: "MyApp", dependencies: [], path: "Sources"),
+  .testTarget(name: "MyAppTests", dependencies: ["MyApp", "SnapshotTesting"])
+]
+```
+
 ### Carthage
 
 If you use [Carthage](https://github.com/Carthage/Carthage), you can add the following dependency to your `Cartfile`:

Sources/SnapshotTesting/Extensions/Wait.swift

@@ -0,0 +1,27 @@
+import Foundation
+import XCTest
+
+extension Snapshotting {
+  /// Transforms an existing snapshot strategy into one that waits for some amount of time before taking the snapshot. This can be useful for waiting for animations to complete or for UIKit events to finish (i.e. waiting for a UINavigationController to push a child onto the stack).
+  /// - Parameters:
+  ///   - duration: The amount of time to wait before taking the snapshot.
+  ///   - strategy: The snapshot to invoke after the specified amount of time has passed.
+  public static func wait(
+    for duration: TimeInterval,
+    on strategy: Snapshotting
+  ) -> Snapshotting {
+    return Snapshotting(
+      pathExtension: strategy.pathExtension,
+      diffing: strategy.diffing,
+      asyncSnapshot: { value in
+        Async { callback in
+          let expectation = XCTestExpectation(description: "Wait")
+          DispatchQueue.main.asyncAfter(deadline: .now() + duration) {
+            expectation.fulfill()
+          }
+          _ = XCTWaiter.wait(for: [expectation], timeout: duration + 1)
+          strategy.snapshot(value).run(callback)
+        }
+    })
+  }
+}

Tests/SnapshotTestingTests/WaitTests.swift

@@ -0,0 +1,17 @@
+import XCTest
+@testable import SnapshotTesting
+
+class WaitTests: XCTestCase {
+  func testWait() {
+    var value = "Hello"
+    DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
+      value = "Goodbye"
+    }
+
+    let strategy = Snapshotting.lines.pullback { (_: Void) in
+      value
+    }
+
+    assertSnapshot(matching: (), as: .wait(for: 1.5, on: strategy))
+  }
+}

Tests/SnapshotTestingTests/__Snapshots__/WaitTests/testWait.1.txt

@@ -0,0 +1 @@
+Goodbye