feat: use --env coverage=false to disable code coverage (#68)

You can skip the client-side code coverage hooks by setting the environment variable `coverage` to `false`.

```shell
cypress run --env coverage=false
cypress open --env coverage=false
CYPRESS_coverage=false cypress run
```

See different ways of setting env variables https://on.cypress.io/environment-variables

Author: bahmutov

README.md

@@ -219,6 +219,23 @@ For example, if you want to only include files in the `app` folder, but exclude
 }
 ```
 
+## Disable plugin
+
+You can skip the client-side code coverage hooks by setting the environment variable `coverage` to `false`.
+
+```shell
+cypress run --env coverage=false
+```
+
+See [Cypress environment variables](https://on.cypress.io/environment-variables) and [support.js](support.js). You can try running without code coverage in this project yourself
+
+```shell
+# run with code coverage
+npm run dev
+# disable code coverage
+npm run dev:no:coverage
+```
+
 ## Links
 
 - Read the [Cypress code coverage guide](http://on.cypress.io/code-coverage)

package.json

@@ -10,7 +10,8 @@
     "dev": "start-test 1234 cy:open",
     "semantic-release": "semantic-release",
     "test:ci": "start-test 1234",
-    "report:coverage": "nyc report --reporter=html"
+    "report:coverage": "nyc report --reporter=html",
+    "dev:no:coverage": "start-test 1234 'cypress open --env coverage=false'"
   },
   "peerDependencies": {
     "cypress": "*",

support.js

@@ -1,75 +1,84 @@
 /// <reference types="cypress" />
-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') })
-})
 
-afterEach(() => {
-  // 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 application code has been instrumented, the app iframe "window" has an object
-    const applicationSourceCoverage = win.__coverage__
-
-    if (applicationSourceCoverage) {
-      cy.task('combineCoverage', applicationSourceCoverage)
-    }
+// to disable code coverage commands and save time
+// pass environment variable coverage=false
+//  cypress run --env coverage=false
+// see https://on.cypress.io/environment-variables
+if (Cypress.env('coverage') === false) {
+  console.log('Skipping code coverage hooks')
+} else {
+  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') })
   })
-})
 
-after(() => {
-  // there might be server-side code coverage information
-  // we should grab it once after all tests finish
-  const baseUrl = Cypress.config('baseUrl') || cy.state('window').origin
-  const runningEndToEndTests = baseUrl !== Cypress.config('proxyUrl')
-  if (runningEndToEndTests) {
-    // we can only request server-side code coverage
-    // if we are running end-to-end tests,
-    // otherwise where do we send the request?
-    const url = Cypress._.get(
-      Cypress.env('codeCoverage'),
-      'url',
-      '/__coverage__'
-    )
-    cy.request({
-      url,
-      log: false,
-      failOnStatusCode: false
+  afterEach(() => {
+    // 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 application code has been instrumented, the app iframe "window" has an object
+      const applicationSourceCoverage = win.__coverage__
+
+      if (applicationSourceCoverage) {
+        cy.task('combineCoverage', applicationSourceCoverage)
+      }
     })
-      .then(r => Cypress._.get(r, 'body.coverage', null), { log: false })
-      .then(coverage => {
-        if (!coverage) {
-          // we did not get code coverage - this is the
-          // original failed request
-          return
-        }
-        cy.task('combineCoverage', coverage)
+  })
+
+  after(() => {
+    // there might be server-side code coverage information
+    // we should grab it once after all tests finish
+    const baseUrl = Cypress.config('baseUrl') || cy.state('window').origin
+    const runningEndToEndTests = baseUrl !== Cypress.config('proxyUrl')
+    if (runningEndToEndTests) {
+      // we can only request server-side code coverage
+      // if we are running end-to-end tests,
+      // otherwise where do we send the request?
+      const url = Cypress._.get(
+        Cypress.env('codeCoverage'),
+        'url',
+        '/__coverage__'
+      )
+      cy.request({
+        url,
+        log: false,
+        failOnStatusCode: false
       })
-  }
+        .then(r => Cypress._.get(r, 'body.coverage', null), { log: false })
+        .then(coverage => {
+          if (!coverage) {
+            // we did not get code coverage - this is the
+            // original failed request
+            return
+          }
+          cy.task('combineCoverage', coverage)
+        })
+    }
 
-  // collect and merge frontend coverage
-  const specFolder = Cypress.config('integrationFolder')
-  const supportFolder = Cypress.config('supportFolder')
+    // collect and merge frontend coverage
+    const specFolder = Cypress.config('integrationFolder')
+    const supportFolder = Cypress.config('supportFolder')
 
-  // if spec bundle has been instrumented (using Cypress preprocessor)
-  // then we will have unit test coverage
-  // NOTE: spec iframe is NOT reset between the tests, so we can grab
-  // the coverage information only once after all tests have finished
-  const unitTestCoverage = window.__coverage__
-  if (unitTestCoverage) {
-    // remove coverage for the spec files themselves,
-    // only keep "external" application source file coverage
-    const coverage = Cypress._.omitBy(
-      window.__coverage__,
-      (fileCoverage, filename) =>
-        filename.startsWith(specFolder) || filename.startsWith(supportFolder)
-    )
-    cy.task('combineCoverage', coverage)
-  }
+    // if spec bundle has been instrumented (using Cypress preprocessor)
+    // then we will have unit test coverage
+    // NOTE: spec iframe is NOT reset between the tests, so we can grab
+    // the coverage information only once after all tests have finished
+    const unitTestCoverage = window.__coverage__
+    if (unitTestCoverage) {
+      // remove coverage for the spec files themselves,
+      // only keep "external" application source file coverage
+      const coverage = Cypress._.omitBy(
+        window.__coverage__,
+        (fileCoverage, filename) =>
+          filename.startsWith(specFolder) || filename.startsWith(supportFolder)
+      )
+      cy.task('combineCoverage', coverage)
+    }
 
-  // when all tests finish, lets generate the coverage report
-  cy.task('coverageReport')
-})
+    // when all tests finish, lets generate the coverage report
+    cy.task('coverageReport')
+  })
+}