keeping code coverage per individual test

bahmutov · bahmutov · commit 42b19ded7697 · 2019-05-16T17:35:39.000-04:00
diff --git a/cypress/app.js b/cypress/app.js
@@ -7,3 +7,7 @@ if (true) {
 } else {
   console.error('never reached')
 }
+
+document.getElementById('click').addEventListener('click', () => {
+  console.log('clicked')
+})
diff --git a/cypress/index.html b/cypress/index.html
@@ -1,5 +1,6 @@
 <body>
   <h2>Test page</h2>
   <p>Open the DevTools to see console messages</p>
+  <button id="click">click me</button>
   <script src="app.js"></script>
 </body>
diff --git a/cypress/integration/spec.js b/cypress/integration/spec.js
@@ -16,4 +16,9 @@ context('Page test', () => {
       .should('have.been.calledOnce')
       .should('have.been.calledWith', 'just names', ['joe', 'mary'])
   })
+
+  it('clicks on the button', function () {
+    cy.get('#click').click()
+    cy.get('@log').should('have.been.calledWith', 'clicked')
+  })
 })
diff --git a/package-lock.json b/package-lock.json
diff --git a/package.json b/package.json
@@ -45,5 +45,8 @@
     "parcel-bundler": "1.12.3",
     "start-server-and-test": "1.9.0",
     "semantic-release": "15.13.12"
+  },
+  "dependencies": {
+    "its-name": "1.0.0"
   }
 }
diff --git a/support.js b/support.js
@@ -1,17 +1,38 @@
 /// <reference types="cypress" />
+const itsName = require('its-name')
+
+let codeCoveragePerTest = new Map()
+
 before(() => {
   // we need to reset the coverage when running
   // in the interactive mode, otherwise the counters will
   // keep increasing every time we rerun the tests
-  cy.task('resetCoverage', { isInteractive: Cypress.config('isInteractive') })
+  const isInteractive = Cypress.config('isInteractive')
+
+  cy.task('resetCoverage', { isInteractive })
+
+  if (isInteractive) {
+    codeCoveragePerTest = new Map()
+  }
 })
 
-afterEach(() => {
+// use "function () {...}" callback to get "this" pointing
+// at the right context
+afterEach(function () {
   // save coverage after each test
   // because the entire "window" object is about
   // to be recycled by Cypress before next test
   cy.window().then(win => {
     if (win.__coverage__) {
+      // only keep track of code coverage per test in the interactive mode
+      if (Cypress.config('isInteractive')) {
+        // testName will be an array of strings
+        const testName = itsName(this.currentTest)
+        console.log('test that finished', testName)
+
+        codeCoveragePerTest[testName] = win.__coverage__
+      }
+
       cy.task('combineCoverage', win.__coverage__)
     }
   })
@@ -20,4 +41,9 @@ afterEach(() => {
 after(() => {
   // when all tests finish, lets generate the coverage report
   cy.task('coverageReport')
+
+  console.log(
+    'after all tests finished, coverage per test is',
+    codeCoveragePerTest
+  )
 })

Original file line number	Diff line number	Diff line change
`@@ -7,3 +7,7 @@ if (true) {`
`7`	`7`	`} else {`
`8`	`8`	`console.error('never reached')`
`9`	`9`	`}`
	`10`	`+`
	`11`	`+document.getElementById('click').addEventListener('click', () => {`
	`12`	`+ console.log('clicked')`
	`13`	`+})`
Original file line number	Diff line number	Diff line change
`@@ -45,5 +45,8 @@`
`45`	`45`	`"parcel-bundler": "1.12.3",`
`46`	`46`	`"start-server-and-test": "1.9.0",`
`47`	`47`	`"semantic-release": "15.13.12"`
	`48`	`+ },`
	`49`	`+ "dependencies": {`
	`50`	`+ "its-name": "1.0.0"`
`48`	`51`	`}`
`49`	`52`	`}`