AccessibilityTextSnapshot

A snapshot strategy for testing your VoiceOvers support in UIKit, using the SnapshotTesting library by PointFree.

This strategy uses a textual representation of the view hierarchy, focusing on just the information that is relevant for VoiceOver. (Related work: AccessibilitySnapshot is a visual snapshot-test tool for a similar use case.)

Usage

import SnapshotTesting
import AccessibilityTextSnapshot

assertSnapshot(                     // SnapshotTesting gives you this...
    matching: someView,
    as: .recursiveA11yDescription)  // ... but AccessibilityTextSnapshot gives you this

This generates a recursive (textual) description of all voiceover-relevant information, suitable for snapshot testing.

The string shows

• all UIView subclasses with isAccessibilityElement true, together with their ancestor UIViews (if any) to show hierarchy
• their voiceover-relevant properties (accessibilityValue, accessibilityLabel, etc)
• any a11y-relevant subviews they might have, prefixed by | to emphasise that they are not involved in VoiceOver

It does not show UIImageViews, which we maybe should reconsider at some point.

Example:

* UIView                                       // non-a11y view but has a11y-relevant descendant
   * UIScrollView                              // (same)
     * UIView                                  // (same)
       * UIStackView                           // ...
         * MDViewLayer.ElementView
           * UIStackView
             * MDViewModels.Label              // | hanging from this view means it has a11y-relevant stuff
             | -label: Relaxation exercises    // a11y property
             | -traits: .staticText            // a11y property
             * UIStackView
               * MDViewLayer.MultilineButton
               | -label: Yes
               | -hint: Unselected option
               | -traits: .button
               * MDViewLayer.MultilineButton
               | -label: No
               | -hint: Unselected option
               | -traits: .button
         * MDViewLayer.ConversationListItemView // hanging | means a11y-relevant view
         | -label: Only you. No messages yet    // a11y property
         | -hint: Open conversation             // a11y property
         | * UIStackView                        // subviews that would be a11y-relevant
         |   * UIStackView                      // BUT are not read by VoiceOver because
         |     * UIStackView                    // the parent view overrides, note leading |
         |       * MDViewModels.Label
         |       | -label: Only you
         |     * UIStackView
         |       * MDViewModels.Label
         |       | -label: No messages yet.
         |   * MDViewLayer.Button
         |     * UIView
         |       * MDViewModels.Label
         |       | -label: Ongoing video call
         o MDViewLayer.StepValidationView        // o means isHidden=true (on self or a parent)
         o -label: Please correct the errors above. Actions available
         o -action: Go to first error            // We still show it because we want to
         o * MDViewLayer.MultilineButton         // be reminded that there *could* be something!
         o | -label: Please correct the errors above

Installing with CocoaPods

target 'MyAppTests' do
  pod 'AccessibilityTextSnapshot'
end