Name: ios-snapshot-test-case
Owner: Wire Swiss GmbH
Description: Snapshot view unit tests for iOS
Forked from: wearezeta/ios-snapshot-test-case
Created: 2016-07-14 14:37:45.0
Updated: 2018-04-10 13:11:27.0
Pushed: 2018-04-10 13:13:15.0
Homepage: null
Size: 849
Language: Objective-C
GitHub Committers
User | Most Recent Commit | # Commits |
---|
Other Committers
User | Most Recent Commit | # Commits |
---|
A “snapshot test case” takes a configured UIView
or CALayer
and uses the
renderInContext:
method to get an image snapshot of its contents. It
compares this snapshot to a “reference image” stored in your source code
repository and fails the test if the two images don't match.
We write a lot of UI code. There are a lot of edge
cases that we want to handle correctly when you are creating UIView
instances:
It's straightforward to test logic code, but less obvious how you should test views. You can do a lot of rectangle asserts, but these are hard to understand or visualize. Looking at an image diff shows you exactly what changed and how it will look to users.
iOSSnapshotTestCase
was developed to make snapshot tests easy.
Add the following lines to your Podfile:
get "Tests" do
se_frameworks!
od 'iOSSnapshotTestCase'
If your test target is Objective-C only use iOSSnapshotTestCase/Core
instead, which doesn't contain Swift support.
Replace “Tests” with the name of your test project.
There are three ways of setting reference image directories, the recommended one is to define FB_REFERENCE_IMAGE_DIR
in your scheme. This should point to the directory where you want reference images to be stored. We normally use this:
|Name|Value|
|:—|:—-|
|FB_REFERENCE_IMAGE_DIR
|$(SOURCE_ROOT)/$(PROJECT_NAME)Tests/ReferenceImages
|
|IMAGE_DIFF_DIR
|$(SOURCE_ROOT)/$(PROJECT_NAME)Tests/FailureDiffs
|
Define the IMAGE_DIFF_DIR
to the directory where you want to store diffs of failed snapshots.
FBSnapshotTestCase
instead of XCTestCase
.FBSnapshotVerifyView
.self.recordMode = YES;
in the test's -setUp
method. (This creates the reference images on disk.)CALayer
via FBSnapshotVerifyLayer
.usesDrawViewHierarchyInRect
to handle cases like UIVisualEffect
, UIAppearance
and Size Classes.isDeviceAgnostic
to allow appending the device model (iPhone
, iPad
, iPod Touch
, etc), OS version and screen size to the images (allowing to have multiple tests for the same «snapshot» for different OS
s and devices).Your unit test must be an “application test”, not a “logic test.” (That is, it must be run within the Simulator so that it has access to UIKit.) In Xcode 5 and later new projects only offer application tests, but older projects will have separate targets for the two types.
iOSSnapshotTestCase
was written at Facebook by
Jonathan Dann with significant contributions by
Todd Krabach.
Today it is maintained by Uber and Alan Zeino.
iOSSnapshotTestCase
is MIT?licensed. See LICENSE
.