coverify

coverify

code coverage browserify transform

example

Suppose we have a test.js:

var test = require('tape');
var foo = require('./foo.js');

test('beep boop', function (t) {
    t.plan(1);
    
    foo(function (err, x) {
        if (err) deadCode();
        t.equal(x * 5, 555);
    });
});

and a foo.js:

module.exports = function (cb) {
    var i = 0;
    var iv = setInterval(function () {
        if (i++ === 10 || (false && neverFires())) {
            clearInterval(iv);
            cb(null, 111);
        }
    }, 10);
};

Now with browserify and testling we can do:

$ browserify -t coverify example/test.js | testling | coverify; echo EXIT CODE: $?

TAP version 13
# beep boop
ok 1 should be equal

1..1
# tests 1
# pass  1

# ok

# /home/substack/projects/coverify/example/test.js: line 7, column 16-28

  if (err) deadCode();
           ^^^^^^^^^^^

# /home/substack/projects/coverify/example/foo.js: line 3, column 35-48

  if (i++ === 10 || (false && neverFires())) {
                              ^^^^^^^^^^^^

EXIT CODE: 1

browserify compiled our test.js file, then testling ran our code in a local headless browser (we also could have used node), and then coverify parsed the test output for code coverage data and printed some nicely formatted results on stderr. Hooray!

methods

var coverify = require('coverify')
var parse = require('coverify/parse')

Usually you can just do browserify -t coverify to get code coverage but you can also use the api directly if you want to use this code directly.

var stream = coverify(file, opts={})

Return a transform stream for file that will instrument the input source file using console.log().

To use a different function from console.log(), pass in opts.output.

var stream = parse(cb)

Return a transform stream that accepts test output as input and looks for lines starting with COVERAGE and COVERED to generate a coverage report in cb(err, coverage). coverage is an object that maps filenames from the bundle files to arrays of coverage data. All of the non-/^(COVERAGE|COVERED)\s/ lines are passed through from the input to the output.

Here is some example coverage data that you can generate with coverify --json:

{
  "/home/substack/projects/coverify/example/test.js": [
    {
      "range": [
        158,
        169
      ],
      "lineNum": 7,
      "column": [
        16,
        28
      ],
      "line": "        if (err) deadCode();",
      "code": "deadCode();"
    }
  ],
  "/home/substack/projects/coverify/example/foo.js": [
    {
      "range": [
        123,
        135
      ],
      "lineNum": 3,
      "column": [
        35,
        48
      ],
      "line": "        if (i++ === 10 || (false && neverFires())) {",
      "code": "neverFires()"
    }
  ]
}

usage

usage: coverify OPTIONS

OPTIONS are:

  --json

    Suppress normal output and print json coverage data to stdout.

  -q, --quiet

    Don't print non-coverage input back out to stdout.

  --stdout

    Always print non-coverage input back out to stdout.

  -o FILE, --output FILE

    Print coverage data to FILE. Use "@2" for stderr (the default) and "@1" or
    "-" for stdout.

install

With npm do:

npm install coverify

to get the browserify transform module.

When you compile your tests with browserify you can just do:

browserify -t coverify ...

You will also need the coverify command for parsing the test output:

npm install -g coverify

license

MIT