55 lines
1.8 KiB
Markdown
55 lines
1.8 KiB
Markdown
# Screenshot testing
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<!--- TOC -->
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* [Overview](#overview)
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* [Setup](#setup)
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* [Recording](#recording)
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* [Verifying](#verifying)
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* [Contributing](#contributing)
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<!--- END -->
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## Overview
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- Screenshot tests are tests which record the content of a rendered screen and verify subsequent runs to check if the screen renders differently.
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- ElementX uses [Paparazzi](https://github.com/cashapp/paparazzi) to render, record and verify Composable. All Composable Preview will be use to make screenshot test, thanks to the usage of [Showkase](https://github.com/airbnb/Showkase).
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- The screenshot verification occurs on every pull request as part of the `tests.yml` workflow.
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## Setup
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- Install Git LFS through your package manager of choice (`brew install git-lfs` | `yay -S git-lfs`).
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- Install the Git LFS hooks into the project.
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```shell
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# with element-android as the current working directory
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git lfs install --local
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```
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If installed correctly, `git push` and `git pull` will now include LFS content.
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## Recording
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It's recommended to delete the content of the folder `/snapshots` before recording.
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```shell
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rm -rf ./tests/uitests/src/test/snapshots
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./gradlew recordPaparazziDebug
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```
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Paparazzi will generate images in `:tests:uitests/src/test/snapshots`, which will need to be committed to the repository using Git LFS.
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## Verifying
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```shell
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./gradlew verifyPaparazziDebug
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```
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In the case of failure, Paparazzi will generate images in `:tests:uitests/out/failure`. The images will show the expected and actual screenshots along with a delta of the two images.
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## Contributing
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- Creating Previewable Composable will automatically creates new screenshot tests.
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- After creating the new test, record and commit the newly rendered screens.
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- `./tools/git/validate_lfs.sh` can be run to ensure everything is working correctly with Git LFS, the CI also runs this check.
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