Jest coverage ignore

Question

I'm trying to ignore a couple of files from my code coverage output. On reading the docs coveragePathIgnorePatterns it looks like I can ignore folders.

I'm trying to ignore dummy and helpers folders from my coverage, but they seem to always be included:

Jest config:

{
  "browser": true,
  "collectCoverageFrom": ["<rootDir>/src/**/*.{js,jsx}", "!<rootDir>/__tests__/__dummy__/test.js"],
  "coveragePathIgnorePatterns": ["<rootDir>/node_modules/", "<rootDir>/__tests__/__helpers__/", "<rootDir>/__tests__/__dummy__/"],
  "roots": [
    "<rootDir>/__tests__/",
    "<rootDir>/src/"
  ],
  "modulePaths": [
    "<rootDir>/src/"
  ],
  "modulePathIgnorePatterns": [
    "<rootDir>/lib/",
    "<rootDir>/node_modules/",
    "<rootDir>/__tests__/__helpers__/",
    "<rootDir>/__tests__/__dummy__/"
  ],
  "setupTestFrameworkScriptFile": "@djforth/jest-matchers",
  "testPathIgnorePatterns": [
    "<rootDir>/__tests__/__dummy__",
    "<rootDir>/__tests__/__dummy__",
    "<rootDir>/lib",
    "<rootDir>/node_modules",
    "<rootDir>/bower_components"
  ],
  "verbose": true
}

I get the following report:

-----------------------|----------|----------|----------|----------|----------------|
File                   |  % Stmts | % Branch |  % Funcs |  % Lines |Uncovered Lines |
-----------------------|----------|----------|----------|----------|----------------|
All files              |    98.87 |    96.48 |     92.5 |    99.55 |                |
 __helpers__           |    84.21 |      100 |    54.55 |    90.91 |                |
  test.js              |    84.21 |      100 |    54.55 |    90.91 |              6 |
 __tests__/__helpers__ |      100 |      100 |      100 |      100 |                |
  create_spy_obj.js    |      100 |      100 |      100 |      100 |                |
 src                   |      100 |       80 |     87.5 |      100 |                |
  index.js             |      100 |       80 |     87.5 |      100 |                |
 src/utils             |      100 |    97.73 |      100 |      100 |                |
  compile_spies.js     |      100 |    81.82 |      100 |      100 |                |
  create_callbacks.js  |      100 |      100 |      100 |      100 |                |
  create_spies.js      |      100 |    97.44 |      100 |      100 |                |
  create_stubs.js      |      100 |      100 |      100 |      100 |                |
  get_spy.js           |      100 |      100 |      100 |      100 |                |
  merger.js            |      100 |      100 |      100 |      100 |                |
  reset_spies.js       |      100 |      100 |      100 |      100 |                |
  title_keys.js        |      100 |      100 |      100 |      100 |                |
-----------------------|----------|----------|----------|----------|----------------|

Answer 1

I have finally figured out what was coursing my issue.

Jest uses Istanbul under the hood. When I set up the project I copied over my .babelrc config and neglected to realize I had left in my old Jasmine config. I had changed to Jest convention of adding tests to __tests__/**/*.test.js, However in .babelrc config I had:

"plugins": [
    [
      "istanbul",
      {
        "exclude": [
          "spec/**/*.spec.js"
        ]
      }
    ],
    "rewire"
  ]

So once I removed the exclude the coverage displays correctly. It looks like if you specify in .babelrc config it overrides the jest config.

Answer 2

Not sure why this not work for you but we do it the other way around:

"collectCoverageFrom": ["src/**/*.js"],