Backend code coverage tests, refactor (#133)

* chore: refactor code

* add test express with code coverage

* start backend test

* npm publish after coverage jobs

* use npx

* last coverage threshold

Author: bahmutov

.circleci/config.yml

@@ -1,10 +1,28 @@
 version: 2.1
 orbs:
-  cypress: cypress-io/cypress@1.13.0
+  cypress: cypress-io/cypress@1.13.0 # used to run e2e tests
+  node: circleci/node@1.1.6 # used to publish new NPM version
+
+jobs:
+  publish:
+    executor:
+      name: node/default
+      tag: '12'
+    steps:
+      - checkout
+      - node/with-cache:
+          steps:
+            - run: npm ci
+      - run: npm run semantic-release
+
 workflows:
   build:
     jobs:
+      - cypress/install
       - cypress/run:
+          name: frontend coverage
+          requires:
+            - cypress/install
           # we need to start the web application
           start: npm start
           # there are no jobs to follow this one
@@ -23,5 +41,31 @@ workflows:
             - run: npx nyc report --check-coverage true --lines 100 --include cypress/about.js
             # make sure unit tests are covered
             - run: npx nyc report --check-coverage true --lines 100 --include cypress/unit.js
-            # publish new version if necessary
-            - run: npm run semantic-release
+
+      - cypress/run:
+          name: backend coverage
+          requires:
+            - cypress/install
+
+          start: npm run start:test:backend
+          command: npx cypress run --config-file cypress-backend.json
+
+          # there are no jobs to follow this one
+          # so no need to save the workspace files (saves time)
+          no-workspace: true
+          post-steps:
+            # store the created coverage report folder
+            # you can click on it in the CircleCI UI
+            # to see live static HTML site
+            - store_artifacts:
+                path: coverage
+            # print code coverage summary to the terminal
+            # and make sure there the coverage is above certain limit
+            - run: npx nyc report --check-coverage true --lines 85
+            # and look at the server index file - should be fully covered
+            - run: npx nyc report --check-coverage true --lines 100 --include test-backend/index.js
+
+      - publish:
+          requires:
+            - frontend coverage
+            - backend coverage

cypress-backend.json

@@ -0,0 +1,9 @@
+{
+  "baseUrl": "http://localhost:3003",
+  "integrationFolder": "cypress/test-backend",
+  "env": {
+    "codeCoverage": {
+      "url": "http://localhost:3003/__coverage__"
+    }
+  }
+}

cypress/test-backend/spec.js

@@ -0,0 +1,5 @@
+/// <reference types="Cypress" />
+it('has backend code coverage', () => {
+  cy.visit('/')
+  cy.request('/hello')
+})