AccessibilitySnapshot

AccessibilitySnapshot makes it simple to add regression tests for accessibility in iOS apps. The framework builds on the idea of snapshot testing to provide snapshots of the accessibility hierarchy.

Getting Started

By default, AccessibilitySnapshot uses SnapshotTesting to record snapshots and perform comparisons. The framework also includes support for using iOSSnapshotTestCase as the snapshotting engine instead. Before setting up accessibility snapshot tests, make sure your project is set up for standard snapshot testing. Accessibility snapshot tests require that the test target has a host application. See the Extensions section below for a list of other available snapshotting options.

CocoaPods

Install with CocoaPods by adding the following to your Podfile:

pod 'AccessibilitySnapshot'

To use only the core accessibility parser, add a dependency on the Core subspec alone:

pod 'AccessibilitySnapshot/Core'

Alternatively, if you wish to use iOSSnapshotTestCase to perform image comparisons, you can add a dependency on the iOSSnapshotTestCase subspec instead (or in addition - you can use both in the same project):

pod 'AccessibilitySnapshot/iOSSnapshotTestCase'

Swift Package Manager

Install with Swift Package Manager by adding the following to your Package.swift:

dependencies: [
    .package(name: "AccessibilitySnapshot", url: "https://github.com/cashapp/AccessibilitySnapshot.git", from: "0.4.1"),
]

Next, add AccessibilitySnapshot as a dependency to your test target:

targets: [
    .target(name: "MyApp"),
    .testTarget(name: "MyAppTests", dependencies: ["MyApp", "AccessibilitySnapshot"])
]

To use only the core accessibility parser, add a dependency on the Core library alone:

targets: [
    .target(name: "MyApp"),
    .testTarget(name: "MyAppTests", dependencies: ["MyApp", "AccessibilitySnapshotCore"])
]

To use iOSSnapshotTestCase to perform image comparisons, add a dependency on FBSnapshotTestCase+Accessibility for Swift testing or FBSnapshotTestCase+Accessibility-ObjC for Objective-C.

targets: [
    .target(name: "MyApp"),
    .testTarget(name: "MyAppTests", dependencies: ["MyApp", "FBSnapshotTestCase+Accessibility"])
]

Carthage

Only the core accessibility parser (not the snapshot integration layers) can be installed via Carthage. To install AccessibilitySnapshotCore via Carthage, add the following to your Cartfile:

github "cashapp/AccessibilitySnapshot"

Bazel

Add the following to your MODULE.bazel file:

bazel_dep(
    name = "accessibility_snapshot",
    version = "x.x.x",
)

Use the provided targets in the BUILD.bazel files. There is a *_library target for each target suffixed with .lib that can be used as a dependency. Without the suffix you will get an ios_framework target (dynamic).

swift_library(
    name = "MyLibrary",
    ...,
    deps = [
        "//Sources/AccessibilitySnapshot/Core:AccessibilitySnapshotCore.lib",
    ],
)

To use iOSSnapshotTestCase you can add a dependency on the //Sources/AccessibilitySnapshot/iOSSnapshotTestCase:AccessibilitySnapshot_iOSSnapshotTestCase targets.

For example:

swift_test(
    name = "MyLibraryTests",
    ...,
    deps = [
        "//Sources/AccessibilitySnapshot/Core:AccessibilitySnapshotCore.lib",
        "//Sources/AccessibilitySnapshot/iOSSnapshotTestCase:AccessibilitySnapshot_iOSSnapshotTestCase",
    ],
)

import AccessibilitySnapshot_iOSSnapshotTestCase

To use SnapshotTesting you can add a dependency on the //Sources/AccessibilitySnapshot/SnapshotTesting:AccessibilitySnapshot_SnapshotTesting targets.

For example:

swift_test(
    name = "MyLibraryTests",
    ...,
    deps = [
        "//Sources/AccessibilitySnapshot/Core:AccessibilitySnapshotCore.lib",
        "//Sources/AccessibilitySnapshot/SnapshotTesting:AccessibilitySnapshot_SnapshotTesting",
    ],
)

import AccessibilitySnapshot_SnapshotTesting

Usage

AccessibilitySnapshot builds on top of existing snapshot frameworks to add support for snapshotting your app's accessibility. By default it uses the SnapshotTesting framework for snapshotting, but can be switched over to iOSSnapshotTestCase as well.

Getting Started with SnapshotTesting

AccessibilitySnapshot provides an .accessibilityImage snapshotting strategy that can be used with SnapshotTesting's snapshot assertions.

func testAccessibility() {
    let view = MyView()
    // Configure the view...

    assertSnapshot(matching: view, as: .accessibilityImage)
}

Snapshots can also be customized in a few ways, for example controlling when to include indicators for the accessibility activation point of each element. By default, these indicators are shown when the activation point is different than the default activation point for that view. You can override this behavior for each snapshot:

func testAccessibility() {
    let view = MyView()
    // Configure the view...

    // Show indicators for every element.
    assertSnapshot(matching: view, as: .accessibilityImage(showActivationPoints: .always))

    // Don't show any indicators.
    assertSnapshot(matching: view, as: .accessibilityImage(showActivationPoints: .never))
}

Getting Started with iOSSnapshotTestCase

To run a snapshot test, simply call the SnapshotVerifyAccessibility method:

func testAccessibility() {
    let view = MyView()
    // Configure the view...

    SnapshotVerifyAccessibility(view)
}

Since AccessibilitySnapshot is built on top of iOSSnapshotTestCase, it uses the same mechanism to record snapshots (setting the self.recordMode property) and supports many of the same features like device agnostic file names and specifying identifiers for each snapshot:

func testAccessibility() {
    let view = MyView()
    // Configure the view...

    SnapshotVerifyAccessibility(view, identifier: "identifier")
}

Snapshots can also optionally include indicators for the accessibility activation point of each element. By default, these indicators are shown when the activation point is different than the default activation point for that view. You can override this behavior for each snapshot:

func testAccessibility() {
    let view = MyView()
    // Configure the view...

    // Show indicators for every element.
    SnapshotVerifyAccessibility(view, showActivationPoints: .always)

    // Don't show any indicators.
    SnapshotVerifyAccessibility(view, showActivationPoints: .never)
}

You can also run accessibility snapshot tests from Objective-C:

- (void)testAccessibility;
{
    UIView *view = [UIView new];
    // Configure the view...

    SnapshotVerifyAccessibility(view, @"identifier");
}

Requirements

• Xcode 13.2.1 or later
• iOS 13.0 or later

Contributing

We love our contributors! Please read our contributing guidelines prior to submitting a pull request.

Extensions

Have you written your own extension? Add it here and submit a pull request!

• PlaybookAccessibilitySnapshot brings accessibility snapshot testing support to Playbook.

License

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.