Add jest coverage diff reporting action (#3651)

.github/workflows/client-build.yml

@@ -93,7 +93,11 @@ jobs:
           echo ::set-output name=version::$next_version-SNAPSHOT
 
       - name: Run the jest tests
-        run: REACT_APP_ENVIRONMENT=${{steps.vars.outputs.REACT_APP_ENVIRONMENT}} yarn run test:unit
+        uses: anuraag016/Jest-Coverage-Diff@V1.1
+        with:
+          fullCoverageDiff: false
+          runCommand: cd app/client && REACT_APP_ENVIRONMENT=${{steps.vars.outputs.REACT_APP_ENVIRONMENT}} yarn run test:unit
+          delta: 0.5
 
       # We burn React environment & the Segment analytics key into the build itself.
       # This is to ensure that we don't need to configure it in each installation

app/client/package.json

@@ -142,7 +142,7 @@
     "eject": "react-scripts eject",
     "start-prod": "REACT_APP_ENVIRONMENT=PRODUCTION craco start",
     "cytest": "REACT_APP_TESTING=TESTING REACT_APP_ENVIRONMENT=DEVELOPMENT craco start & ./node_modules/.bin/cypress open",
-    "test:unit": "$(npm bin)/jest -b --colors --no-cache",
+    "test:unit": "$(npm bin)/jest -b --colors --no-cache --coverage --collectCoverage=true --coverageDirectory='./' --coverageReporters='json-summary'",
     "storybook": "start-storybook -p 9009 -s public",
     "build-storybook": "build-storybook -s public"
   },