cocoon

Mutate getters (that return functions) into mockable/spyable functions.

Usage no npm install needed!

<script type="module">
  import cocoon from 'https://cdn.skypack.dev/cocoon';
</script>

README

Cocoon

A small utility module for wrapping property getters within functions.

It is useful as a TDD helper for creating mockable/spyable methods on top of another library's methods that are returned via a getter.

Note: This is not a cure-all. Objects could be frozen, etc.

Example

    var lib = {}
    function foo() {}
    lib.__defineGetter__('foo', function () { return foo })

With something like sinon, you can't (at the moment) mock setters.

With cocoon, you can:

    var cocoon = require('cocoon')

    var c = cocoon
                .spin(lib)
                .wrap('foo')

    ..

    sinon.stub(lib, 'foo') // works

    c.restore()

Yay.

However.. if:

    var self = {}

    function foo() {}
    self.__defineGetter__('foo', function () { return foo })
    Object.freeze(self)
    module.exports = self

..Nope. Not going to happen.