context.document is undefined for some actions so it breaks the API

[cameronmcefee]

In the manifest commands:

 "script": "myscript.js",
"handlers": {
  "actions": {
    "SelectionChanged.finish": "onSelectionChanged"
  }
}

in myscript.js

var onSelectionChanged = function(context) {
  var sketch = context.api()

  log(sketch.api_version)
  log(sketch.version)
  log(sketch.build)
  log(sketch.full_version)

  var document = sketch.selectedDocument;
  log(document.selectedLayers);
}

When changing selection:

TypeError: null is not an object (evaluating 'this._object.currentPage')
line: 810
sourceURL: /Applications/Sketch.app/Contents/Resources/SketchAPI.js
column: 41

Looks like the code in question is:

{
  key: 'selectedPage',
  get: function get() {
    return new _Page.Page(this._object.currentPage(), this);
  }
}

[DanielRuf]

It also seems the readme is not up to date.

[mathieudutour]

the readme is up to date with the develop branch which is not released yet