code-coverage: nyc out.json is empty

vue/node js project running with cypress tests, trying to add coverage the nyc_output folder is there also the processinto folder The out.json file is either empty or not created, depending on how i play with the setting files I also see in the cypress run that the after all task - covergereport runs, but the after each task - combine coverge does not run

my plugins index file has the

on('task', require('@cypress/code-coverage/task'))

my babel

"babel": {
    "plugins": ["istanbul"],
    "presets": [
      [
        "@babel/preset-env",
        {
          "modules": "commonjs",
          "targets": {
            "node": "current"
          }
        }
      ]
    ]

nycrc
{
        "extends": "@istanbuljs/nyc-config-babel",
        "extension": [".js", ".vue"],
        "all": true
}

my command line

nyc --all npm run test:open

my json has

"devDependencies": {
    "@babel/core": "^7.5.0",
    "@babel/preset-env": "^7.5.2",
    "@cypress/code-coverage": "^1.10.1",
    "@vue/cli-plugin-babel": "^3.8.0",
    "@vue/cli-plugin-eslint": "^3.8.0",
    "@vue/cli-plugin-unit-jest": "^3.7.0",
    "@vue/cli-service": "^3.8.0",
    "@vue/eslint-config-standard": "^4.0.0",
    "@vue/test-utils": "^1.0.0-beta.29",
    "axios-mock-adapter": "^1.17.0",
    "babel-core": "7.0.0-bridge.0",
    "babel-eslint": "^10.0.1",
    "babel-jest": "^22.4.3",
    "babel-plugin-component": "^1.1.1",
    "babel-plugin-istanbul": "^5.2.0",
    "cypress": "^3.4.1",
    "cypress-failed-log": "^2.5.1",
    "eslint": "^5.16.0",
    "eslint-plugin-cypress": "^2.0.1",
    "eslint-plugin-cypress-dev": "2.1.0",
    "eslint-plugin-jest": "^22.7.2",
    "eslint-plugin-mocha": "5.3.0",
    "eslint-plugin-vue": "^5.0.0",
    "gulp-babel": "^8.0.0",
    "istanbul-lib-coverage": "^2.0.5",
    "jest": "^24.8.0",
    "jest-html-reporter": "^2.5.0",
    "jest-junit": "^6.4.0",
    "jest-transform-stub": "^2.0.0",
    "nodemon": "^1.19.1",
    "nyc": "^14.1.1",
    "sass": "^1.18.0",
    "sass-loader": "^7.1.0",
    "start-server-and-test": "^1.10.0",
    "stylus": "^0.54.5",
    "stylus-loader": "^3.0.1",
    "supertest": "^4.0.2",
    "supertest-as-promised": "^4.0.2",
    "vue-cli-plugin-vuetify": "^0.5.0",
    "vue-jest": "^3.0.4",
    "vue-template-compiler": "^2.6.10",
    "vue-test-utils": "^1.0.0-beta.11",
    "vuetify-loader": "^1.0.5",
    "vuex-mock-store": "0.0.7",
    "wait-on": "^3.3.0"

what am i missing?

About this issue

Original URL
State: closed
Created 5 years ago
Reactions: 1
Comments: 22 (3 by maintainers)

Most upvoted comments

We have the same problem here 😦

leorigon on Oct 1, 2019

I’m facing a problem where the window.coverage is always coming “undefined” even after following all the Cypress code coverage documentation steps with various instrumentation options mentioned… and when starting my server with the cmd

  "scripts": {
    "start": "PORT=7777 react-app-rewired -r @cypress/instrument-cra start",
}

I get the following error

EvalError: Refused to evaluate a string as JavaScript because ‘unsafe-eval’ is not an allowed source of script in the following Content Security Policy directive: "script-src ‘self’ ‘unsafe-inline’

Appreciate your help on this @bahmutov

KarimElKhashab on Jul 17, 2020

@elaco77 I have copied your example - you are not instrumenting your code, once you follow https://github.com/cypress-io/instrument-cra or https://github.com/bahmutov/testing-react#installation instructions your source code will be instrumented on the fly, and code coverage will be saved

bahmutov on Feb 3, 2020

The issue for me was during production build mode, I had to force my plugin to do instrumentation (vite-plugin-istanbul + forceBuildInstrumentation option).

ngokevin on Jun 2, 2022

@bahmutov here’s a repo where you can reproduce the issue. However I run the test, the nyc/out.json remains empty.

Feel free to contribute on the repo if you feel so. Also, let me know if there’s anything else I can do.

https://github.com/elaco77/cypress-code-coverage-showcase

elaco77 on Nov 21, 2019

I fixed this issue on our project (we using TypeScript) re-installing the dependencies and putting these codes:

package.json

"scripts": {
   "cy:run:report": "nyc --reporter=html cypress run"
},
"devDependencies": {
    "@istanbuljs/nyc-config-typescript": "0.1.3",
    "babel-plugin-istanbul": "5.2.0",
    "source-map-support": "0.5.16",
    "@cypress/code-coverage": "1.10.1",
    "istanbul-lib-coverage": "2.0.5",
    "nyc": "14.1.1"
},
"nyc": {
    "extends": "@istanbuljs/nyc-config-typescript",
    "extension": [
      ".tsx"
    ],
    "include": [
      "src/**/*.tsx"
    ],
    "exclude": [
      "cypress/",
      "assets/",
      "test/"
    ],
    "all": true
  }

.babelrc

"plugins": ["istanbul"]

added in plugins/index.js module.exports:

on('task', require('@cypress/code-coverage/task'))

and support/index.ts

import '@cypress/code-coverage/support'

It’s works for now, but I can improve these.

leorigon on Jan 7, 2020