add example with just unit test code coverage (#384)

Author: bahmutov

.circleci/config.yml

@@ -520,6 +520,36 @@ workflows:
                   ../../node_modules/.bin/only-covered main.js
                 working_directory: examples/one-spec
 
+      - cypress/run:
+          attach-workspace: true
+          name: example-unit-tests-js
+          requires:
+            - cypress/install
+          # there are no jobs to follow this one
+          # so no need to save the workspace files (saves time)
+          no-workspace: true
+          command: npx cypress run --project examples/unit-tests-js
+          # store screenshots and videos
+          store_artifacts: true
+          post-steps:
+            - run: cat examples/unit-tests-js/.nyc_output/out.json
+            - run: cat examples/unit-tests-js/coverage/coverage-summary.json
+            # store the created coverage report folder
+            # you can click on it in the CircleCI UI
+            # to see live static HTML site
+            - store_artifacts:
+                path: examples/unit-tests-js/coverage
+            # make sure the examples captures 100% of code
+            - run:
+                command: npx nyc report --check-coverage true --lines 100
+                working_directory: examples/unit-tests-js
+            - run:
+                name: Check code coverage 📈
+                command: |
+                  ../../node_modules/.bin/check-coverage misc.js
+                  ../../node_modules/.bin/only-covered misc.js
+                working_directory: examples/unit-tests-js
+
       - cypress/run:
           name: Windows test
           executor:
@@ -579,4 +609,5 @@ workflows:
             - example-use-webpack
             - example-all-files
             - example-placeholders
+            - example-unit-tests-js
             - Windows test

README.md

@@ -136,6 +136,8 @@ module.exports = (on, config) => {
 
 Now the code coverage from spec files will be combined with end-to-end coverage.
 
+Find example of a just the unit tests and JavaScript source files with collected code coverage in [examples/unit-tests-js](./examples/unit-tests-js).
+
 ### Alternative for unit tests
 
 If you cannot use `.babelrc` for some reason (maybe it is used by other tools?), try using the Browserify transformer included with this module in `use-browserify-istanbul` file.
@@ -401,6 +403,7 @@ Full examples we use for testing in this repository:
 - [examples/one-spec.js](examples/one-spec.js) confirms that coverage is collected and filtered correctly if the user only executes a single Cypress test
 - [examples/ts-example](examples/ts-example) uses Babel + Parcel to instrument and serve TypeScript file
 - [examples/use-webpack](examples/use-webpack) shows Webpack build with source maps and Babel
+- [examples/unit-tests-js](examples/unit-tests-js) runs just the unit tests and reports code coverage (JavaScript source code)
 
 ### External examples
 

examples/unit-tests-js/.babelrc

@@ -0,0 +1,3 @@
+{
+  "plugins": ["istanbul"]
+}

examples/unit-tests-js/README.md

@@ -0,0 +1,3 @@
+# example: unit-tests-js
+
+Examples that only run unit tests written using JavaScript

examples/unit-tests-js/cypress.json

@@ -0,0 +1,3 @@
+{
+  "fixturesFolder": false
+}

examples/unit-tests-js/cypress/integration/spec.js

@@ -0,0 +1,13 @@
+/// <reference types="cypress" />
+import { isObject, add } from '../../src/utils/misc'
+
+describe('unit tests', () => {
+  it('adds two numbers', () => {
+    expect(add(2, 3)).to.equal(5)
+  })
+
+  it('checks for object', () => {
+    expect(isObject({}), '{}').to.be.true
+    expect(isObject([]), '[]').to.be.true
+  })
+})

examples/unit-tests-js/cypress/plugins/index.js

@@ -0,0 +1,5 @@
+module.exports = (on, config) => {
+  require('../../../../task')(on, config)
+  on('file:preprocessor', require('../../../../use-babelrc'))
+  return config
+}

examples/unit-tests-js/cypress/support/index.js

@@ -0,0 +1 @@
+import '../../../../support'

examples/unit-tests-js/package.json

@@ -0,0 +1,7 @@
+{
+  "name": "example-unit-tests-js",
+  "description": "Run unit tests written using JavaScript",
+  "scripts": {
+    "cy:open": "../../node_modules/.bin/cypress open"
+  }
+}

examples/unit-tests-js/src/utils/misc.js

@@ -0,0 +1,13 @@
+/**
+ * Very simple check, returns true for arrays as well
+ */
+export function isObject(object) {
+  return object != null && typeof object === 'object'
+}
+
+/**
+ * Adds two numbers together
+ * @param {number} a
+ * @param {number} b
+ */
+export const add = (a, b) => a + b