How to ignore lines for code coverage in Jest

Solution 1:

It works.

(function(global) {
    var defineAsGlobal = true;
    /* istanbul ignore next */
    if(typeof exports === 'object') {
        module.exports = lib;
        defineAsGlobal = false;
    }
    /* istanbul ignore next */
    if(typeof modules === 'object' && typeof modules.define === 'function') {
        modules.define('lib', function(provide) {
            provide(lib);
        });
        defineAsGlobal = false;
    }
    /* istanbul ignore next */
    if(typeof define === 'function') {
        define(function(require, exports, module) {
            module.exports = lib;
        });
        defineAsGlobal = false;
    }
    /* istanbul ignore next */
    defineAsGlobal && (global.lib = lib);
})(this);

Sample project https://github.com/ilyar/sandbox/tree/master/jest

Solution 2:

Update for anyone that finds this at a later date.

/* istanbul ignore next */ 

Will work but as read from The Jest Official Documentation:

coveragePathIgnorePatterns seems to not have any effect.

Make sure you are not using the babel-plugin-istanbul plugin. Jest wraps Istanbul, and therefore also tells Istanbul what files to instrument with coverage collection. When using babel-plugin-istanbul, every file that is processed by Babel will have coverage collection code, hence it is not being ignored by coveragePathIgnorePatterns.

The documentation can be found here: Documentation

So in order to fix this issue uninstall babel-plugin-istanbul:

If it is a library based only on javascript, than you can just run npm uninstall --save babel-plugin-istanbul or npm uninstall --save-dev babel-plugin-istanbul If you've installed a library with native content that requires linking, and you've linked it with rnpm then you can do: rnpm unlink package_name then follow step 1 - Aakash Sigdel

This quote was from Aakash Sigdel found here: quote

Solution 3:

Found a workaround (spaces before and after the comment seem to be necessary):

class Foo {
  bar /* istanbul ignore next */ () {
    return 'biu~';
  }
}

Solution 4:

In my case, I had coverageProvider: 'v8', and it was causing this to break. doing: coverageProvider: 'babel', fixed it and the pragma works great.