Paparazzi

An Android library to render your application screens without a physical device or emulator.

class LaunchViewTest {
  @get:Rule
  val paparazzi = Paparazzi(
    deviceConfig = PIXEL_5,
    theme = "android:Theme.Material.Light.NoActionBar"
    // ...see docs for more options 
  )
 
  @Test
  fun simple() {
    val view = paparazzi.inflate<LaunchView>(R.layout.launch)
    // or... 
    // val view = LaunchView(paparazzi.context)
    
    view.setModel(LaunchModel(title = "paparazzi"))
    paparazzi.snapshot(view)
  }
}

See the project website for documentation and APIs.

Tasks

$ ./gradlew sample:testDebug

Runs tests and generates an HTML report at sample/build/reports/paparazzi/ showing all test runs and snapshots.

$ ./gradlew sample:recordPaparazziDebug

Saves snapshots as golden values to a predefined source-controlled location (defaults to src/test/snapshots).

$ ./gradlew sample:verifyPaparazziDebug

Runs tests and verifies against previously-recorded golden values.

For more examples, check out the sample project.

Git LFS

It is recommended you use Git LFS to store your snapshots. Here's a quick setup:

$ brew install git-lfs
$ git config core.hooksPath  # optional, confirm where your git hooks will be installed
$ git lfs install --local
$ git lfs track **/snapshots/**/*.png
$ git add .gitattributes

On CI, you might set up something like:

$HOOKS_DIR/pre-receive

# compares files that match .gitattributes filter to those actually tracked by git-lfs
diff <(git ls-files ':(attr:filter=lfs)' | sort) <(git lfs ls-files -n | sort) >/dev/null

ret=$?
if [[ $ret -ne 0 ]]; then
  echo >&2 "This remote has detected files committed without using Git LFS. Run 'brew install git-lfs && git lfs install' to install it and re-commit your files.";
  exit 1;
fi

your_build_script.sh

if [[ is running snapshot tests ]]; then
  # fail fast if files not checked in using git lfs
  "$HOOKS_DIR"/pre-receive
  git lfs install --local
  git lfs pull
fi

Jetifier

If using Jetifier to migrate off Support libraries, add the following to your gradle.properties to exclude bundled Android dependencies.

android.jetifier.ignorelist=android-base-common,common

Releases

Our change log has release history.

Using plugin application:

buildscript {
  repositories {
    mavenCentral()
    google()
  }
  dependencies {
    classpath 'app.cash.paparazzi:paparazzi-gradle-plugin:0.9.3'
  }
}

apply plugin: 'app.cash.paparazzi'

Using the plugins DSL:

plugins {
  id 'app.cash.paparazzi' version '0.9.3'
}

Snapshots of the development version are available in Sonatype's snapshots repository.

 repositories {
   // ...
   maven {
     url 'https://oss.sonatype.org/content/repositories/snapshots/'
   }
 }

Known Limitations

Running Tests from the IDE

java.lang.NullPointerException
  at java.base/java.io.File.<init>(File.java:278)
  at app.cash.paparazzi.EnvironmentKt.detectEnvironment(Environment.kt:36)

Running tests from the IDE requires Android Studio Arctic Fox or later.

Could not find ... resource matching value 0x... (resolved name: ...) in current configuration.

Could not find dimen resource matching value 0x10500C0 (resolved name: config_scrollbarSize) in current configuration.
android.content.res.Resources$NotFoundException: Could not find dimen resource matching value 0x10500C0 (resolved name: config_scrollbarSize) in current configuration.

Could not find integer resource matching value 0x10E00B4 (resolved name: config_screenshotChordKeyTimeout) in current configuration.
android.content.res.Resources$NotFoundException: Could not find integer resource matching value 0x10E00B4 (resolved name: config_screenshotChordKeyTimeout) in current configuration.

compileSdkVersion has to be 29 or higher.

android {
  compileSdkVersion 29
}

License

Copyright 2019 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.