TypeError exception on array comparison

[febeling]

This test passes with 0.5.4 and fails with 0.5.5

    it('jsonpatch array compare', function () {
      var a = ['foo', 'bar']
      var b = ['foo', 'bar', 'baz']

      expect(jsonpatch.compare(b, a)).toEqual([
        { op: 'remove', path: '/2' }
      ])
      expect(jsonpatch.compare(a, b)).toEqual([
        { op: 'add', path: '/2', value: 'baz' }
      ])
    })

This is the stacktrace:

PhantomJS 1.9.8 (Mac OS X 0.0.0) Service: utility changes to get from updated to original jsonpatch array compare FAILED
    TypeError: '[object Object]' is not a valid argument for 'Function.prototype.apply' (evaluating 'obj.length')
        at /Users/febeling/work/ehealth/sl-ebola-call-admin/app/bower_components/fast-json-patch/src/json-patch-duplex.js:29
        at _generate (/Users/febeling/work/ehealth/sl-ebola-call-admin/app/bower_components/fast-json-patch/src/json-patch-duplex.js:405)
        at compare (/Users/febeling/work/ehealth/sl-ebola-call-admin/app/bower_components/fast-json-patch/src/json-patch-duplex.js:537)
        at /Users/febeling/work/ehealth/sl-ebola-call-admin/test/spec/services/utility.js:117

Updated: showing tests exercising the library API directly, instead of our thin service layer.

[warpech]

@miyconst could you please take a look?

[miyconst]

Sure.

[miyconst]

@febeling, could you please provide your full testing environment?

And could you try to replace

return Array.apply(null, { length: obj.length }).map(function (e, i, a) { return i.toString(); });

at https://github.com/Starcounter-Jack/JSON-Patch/blob/master/src/json-patch-duplex.js#L29

with

var keys = new Array(obj.length);

for (var i = 0; i < keys.length; i++) {
    keys[i] = i.toString();
}

return keys;

And let me know whether it passes.

[febeling]

The tests are written with jasmine and run in karma, controlling a phantomjs browser runtime.

I can't reproduce the problem in plain node.

The problem goes away when switching karma to use Chrome as browser runtime.

With the change to loop iteration you propose above it also works with phantomjs.

[miyconst]

Should be fixed in 0.5.6

[febeling]

Confirming the fix. Thanks!