feebas-lib v0.1.4

feebas

Feebas is screenshot comparison tool which is intended to be used as a part of catching the visual regressions in end to end tests.

npm install --save-dev feebas

how it works?

The basic philosophy of feebas is to compare current screenshots (e.g. screenshots taken during e2e tests in pipeline) with truth screenshots which defines the desired appearance of the application.

recommended setup and workflow

1. Screenshot your application during e2e tests in pipeline (e.g. gitlab pipeline) and save the screenshots as job artifacts. If you are using Cypress you can use screenshot function to take screenshots.
2. Define the truth screenshots (e.g. with first run of the pipeline) and save them into your repository. Setup GIT LFS for your repository to handle the big files.
3. Setup feebas (proceed to section - setup)

Now, when your pipeline fails because of visual regression.

1. Checkout on the commit of that pipeline - run git checkout <commit_id>
2. Open feebas - npx feebas
3. Look for the differences in screenshots

• if your visual changes were intended
  • Select screenshots you want to update
  • Click on the approve button in top right corner
  • It will overwrite screenshots in the repository, so you need to git add . them and then git commit them
• if your visual changes were not intended
  • Fix the source of visual regression (bug)
  • Push the fix and proceed to the first step

setup

1. Install feebas npm install --save-dev feebas (you probably want it as a dev dependency)

2. Create feebas.config.json in your project root, the file should look like this. Alternatively you can provide path to configuration file - npx feebas --config ./example/path/to/feebas.config.json. Example file with gitlab integration is available here.

   {
       "projects": [
           {
               "name": "example",
               "screenshots": {
                   "current": {
                      ... // some integration (e.g. gitlab)
                   },
                   "truth": {
                      "type": "fs-local",
                      "path": "./example/path/to/truth_screenshots"
                  }
               }
           }
       ]
   }

integrations

gitlab

• url - string - gitlab url
• project_id - number - id of the gitlab project - repository
• authentication - object
  • type - string - type of authentication into the gitlab, currently is available authentication only with access token. For authentication with access_token get your gitlab access token and set it into the environment variable FEEBAS_GITLAB_TOKEN.
• jobs - array - array of jobs from which will be downloaded screenshots.
  • job
    • name - string - name of the job
    • path - string (optional) - path to the directory inside job artifacts (e.g. to the directory where are current screenshots stored)

          {
            "name": "exmaple job name",
            "path": "/example/path"
          }

• strategy - string - "merge" | "default" (optional) - when merge option is used all artifacts from the jobs will be merged, otherwise they will be stored in the directory with name of their job name
• filter - object - you can define files from artifacts which will be ignored
  • rules - array of strings
  • strategy - "blacklist" | "whitelist"

        {
              "rules": ["*(failed)*", "tmp_*"],
              "strategy": "blacklist"
        }

opening specific project and commit (experimental)

It is possible to open feebas from your browser. Just open URL in this format: feebas://projectId:commitId.

Development

Development instructions are available here.