jscoverage.md

   1 ---
   2 title: jscoverage
   3 category: JavaScript libraries
   4 layout: 2017/sheet
   5 intro: |
   6   A small guide into installing [jscoverage](https://npmjs.com/package./jscoverage). Also see [mocha-blanket](./mocha-blanket).
   7 ---
   8
   9 ### Install
  10
  11 #### Install via npm
  12
  13 ```bash
  14 npm install --save-dev jscoverage
  15 ```
  16
  17 #### Ignore output
  18
  19 ```bash
  20 echo coverage.html >> .gitignore
  21 ```
  22
  23 ### package.json
  24
  25 The `coverage` task injects your source files (`lib`) with jscoverage hooks, runs `mocha -R html-cov`, then restores later.
  26 {: .-setup}
  27
  28 ```bash
  29 /* directory */
  30 "coverage": "mv lib lib~; (jscoverage lib~ lib; mocha -R html-cov > coverage.html); rm -rf lib; mv lib~ lib"
  31 ```
  32 {: .-hard-wrap}
  33
  34 ```bash
  35 /* single file */
  36 "coverage": "(cp index.js index.js~; jscoverage index.js; mv index-cov.js index.js; mocha -R html-cov > coverage.html); mv index.js~ index.js"
  37 ```
  38 {: .-hard-wrap}
  39
  40 ### Run
  41
  42 ```bash
  43 npm run coverage
  44 ```
  45
  46 ```bash
  47 open coverage.html
  48 ```
  49
  50 ### Caveats
  51
  52 If you're using jsdom, be sure to expose the `window._$jscoverage` variable into
  53 the `global` scope.