POC roborazzi add screenshots.md file

.github/workflows/compare_screenshots.yml

@@ -111,4 +111,4 @@ jobs:
         with:
           name: failure-report
           path: 'reports/*'
-          retention-days: 14
+          retention-days: 1

screenshots.md

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+## Screenshot testing
+Screenshot tests compares current screenshots of the app with a set of desired ones. To achieve that we need to perform 2 tasks:
+
+	1. Generate and store a set of desired screenshots (also known as baseline). 
+	These screenshots will be generated using a reference device to avoid differences based on Android devices/versions
+	2. Take screenshots of the app with this reference device and compare them with the baseline. 
+	Then generate reports with differences detected
+
+To perform these tasks we use [Roborazzi](https://github.com/takahirom/roborazziot) library which uses gradle tasks to generate baseline and store screenshots
+
+## Add a new screenshot
+To create a new screenshot create a new unitTest with Roboelectric in the test folder of the module to test:
+    @RunWith(RobolectricTestRunner::class)
+or
+    @RunWith(ParameterizedRobolectricTestRunner::class)
+depending if it's a parametrized test or not, use
+    @RunWith(Enclosed::class)
+to mix them (`ButtonKtTest.kt` is an example of this)
+
+Then use `captureRoboImage()` function to take the screenshot and use `ScreenshotUtils.getScreenshotName()` to set the name of the test.:
+
+    composeTestRule.onRoot()
+            .captureRoboImage(ScreenshotUtils.getScreenshotName())
+
+For traditional views run an activity or check `TextInputTest.kt` example on how to use a dummy activity to load them inside.
+
+## Check that changes in the screen are detected
+`Compare Screenshots` job will run in each pr and will run the `verifyRoborazziDebug` gradle task that checks the screenshots. In case this fails it will 
+generate a report and upload it to azure.
+
+## Access to screenshots test report
+At the bottom of the action that has failed you'll see that a report has been uploaded either to azure or github artifacts (or both), this is still to be 
+determined. 
+
+Once that compressed file is downloaded an html report is there with the differences detected between the current screenshot (left side) and the 
+newly generated one (right side).
+
+## Update screenshots baseline with a Github action
+Either run the ci job `Update screenshot baseline` that will create the images and perform a commit for you or run the gradle task `recordRoborazziDebug` and
+this way it allows you to check everything is ok before uploading the images.
+
+
+