Paparazzi

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

See the project website for documentation and APIs.

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

Git LFS

It is recommended you use Git LFS to store your snapshots. Here's a template to get started.

`.gitattributes`

**/snapshots/**/*.png filter=lfs diff=lfs merge=lfs -text

`.hooks/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

`.hooks/post-checkout`

# Call the git-lfs filter (except in CI)
if [[ not CI ]]; then
  command -v git-lfs >/dev/null 2>&1 || { echo >&2 "This repository is configured for Git LFS but 'git-lfs' was not found on your path. Run 'brew install git-lfs && git lfs install' to install it."; exit 2; }
  git lfs post-checkout "$@"
fi

`.hooks/post-commit`

# Call the git-lfs filter (except in CI)
if [[ not CI ]]; then
  command -v git-lfs >/dev/null 2>&1 || { echo >&2 "This repository is configured for Git LFS but 'git-lfs' was not found on your path. Run 'brew install git-lfs && git lfs install' to install it."; exit 2; }
  git lfs post-commit "$@"
fi

`.hooks/post-merge`

# Call the git-lfs filter (except in CI)
if [[ not CI ]]; then
  command -v git-lfs >/dev/null 2>&1 || { echo >&2 "This repository is configured for Git LFS but 'git-lfs' was not found on your path. Run 'brew install git-lfs && git lfs install' to install it."; exit 2; }
  git lfs post-merge "$@"
fi

`.hooks/pre-push`

# Call the git-lfs filter (except in CI)
if [[ not CI ]]; then
  command -v git-lfs >/dev/null 2>&1 || { echo >&2 "This repository is configured for Git LFS but 'git-lfs' was not found on your path. Run 'brew install git-lfs && git lfs install' to install it."; exit 2; }
  git lfs pre-push "$@"
fi

`your CI script`

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

Releases

Our change log has release history.

Using plugin application:

buildscript {
  repositories {
    mavenCentral()
    google()
  }
  dependencies {
    classpath 'app.cash.paparazzi:paparazzi-gradle-plugin:0.8.0'
  }
}

apply plugin: 'app.cash.paparazzi'

Using the plugins DSL:

plugins {
  id 'app.cash.paparazzi' version '0.8.0'
}

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

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

Tasks

$ ./gradlew some-project:testDebug

Runs tests and generates an HTML report at some-project/build/reports/paparazzi/debug/ showing all test runs and snapshots.

$ ./gradlew some-project:recordPaparazziDebug

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

$ ./gradlew some-project:verifyPaparazziDebug

Runs tests and verifies against previously-recorded golden values.

Check out the sample.

Known Limitations

Resource Resolution Errors

Ex:

java.lang.NullPointerException
  at com.android.ide.common.resources.ResourceResolver.getUnresolvedResource(ResourceResolver.java:421)

Paparazzi does not currently support namespaced resources. If you are seeing this error, verify that the following flag is not present in the project's gradle.properties: android.nonTransitiveRClass=true

Running Tests from the IDE

Ex:

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.

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.

TWiStErRob / paparazzi