Angular.copy support for ES6 Map (and other ES6 types?) #16067
Description
I'm submitting a ...
- bug report
- feature request
- other (Please do not submit support requests here (see above))
Current behavior:
angular.copy when called on an object containing an ES6 Map object fails to copy the Map contents. This is surprising for the developer-user since they would expect the new object to contain all the attributes of the old one, including contents (angular.copy advertises as a deep copy)
Expected / new behavior:
Addition of ES6 Map copy would mean angular.copy behaves as expected regardless of the presence of a Map in an object.
I haven't looked at other ES6 types, but I would expect angular.copy should sensibly copy them as well, if it doesn't already.
Minimal reproduction of the problem with instructions:
> m = new Map()
Map(0) {}
> m.set('a', 'b')
Map(1) {"a" => "b"}
> o = {myProperty : m}
Object {myProperty: Map(1)}
> c = angular.copy(o)
Object {myProperty: Map}
> o.myProperty
Map(1) {"a" => "b"}
> c.m
Map {}
Angular version: 1.x.y
1.6.4-local+sha.617b36117
looking at latest code, it is iterating keys, which won't work for maps:
https://github.com/angular/angular.js/blob/master/src/Angular.js#L902
> m = new Map()
Map(0) {}
> m.set('a', 'b')
Map(1) {"a" => "b"}
> for (k in m) { console.log(k)}
undefined
Browser: [all | Chrome XX | Firefox XX | Edge XX | IE XX | Safari XX | Mobile Chrome XX | Android X.X Web Browser | iOS XX Safari | iOS XX UIWebView | iOS XX WKWebView ]
Chrome 59.0.3071.86 (Official Build) (64-bit)
Tried replicating on Firefox, but was an older version of angular and caused error:
> m = new Map()
Map { }
> m.set('a', 'b')
Map { a: "b" }
> c = angular.copy(m)
TypeError: Map.prototype.forEach called on incompatible object
> angular.version
Object { full: "1.3.20", major: 1, minor: 3, dot: 20, codeName: "shallow-translucence" }
Looking at code, though it wouldn't work for Map on any browser that doesn't allow key iteration over map values (every browser I suspect).
For example, on FF:
> for (k in m) { console.log(k)}
undefined
Anything else:
This overlaps with the following issue:
#10304
However, that issue is talking about general 'iterable' object support (of which ES6 collections are a sub-set) which is a more intractable problem. This is focused specifically on ES6 collections.
Suggest treating Map similar to Array as a special case and using the built-in iteration features to populate the copy.
Alternately, define a global javascript 'clone' standard that objects can declare support for and make angular.copy redundant ;)