Please don't use proxies unnecessarily. They are bad for performance. On Mon, Nov 20, 2017 at 5:05 PM, Joe Hildebrand <jhildebr...@mozilla.com> wrote:
> You could also potentially use a Proxy object: > > https://gist.github.com/hildjj/1ac6e3d52e4e0d23f6289d73c1840a5a > > > On Nov 20, 2017, at 9:00 AM, Richard Newman <rnew...@mozilla.com> wrote: > > > > Are there alternative ways we could achieve the same without the (or > with low) complexity/overhead? > > > > If I'm understanding correctly what you're trying to do, the typical > suggestion here is to not use global singletons. That way you don't need to > dig into the guts of a globally visible object in order to test it; you can > pass your own part-mocked Object instance into whatever mechanism is trying > to call `Object.foo`. > > > > In your `foo`/`bar` case, you'd pass a `MockObject` to `bar`, and verify > that `MockObject.foo` was called. We do this all the time in codebases that > use less dynamic languages (e.g., Fennec and Firefox for iOS). > > > > This doesn't help you to test existing singleton-based JS code… but > then, if that code is already using Object.freeze, then you already can't, > and you'll be having to change _something_. > > > > I mostly agree with Nicolas's sentiment; poking at the guts of code > outside your own module (or even in your own module!) isn't really a kind > of software development that I feel we should encourage. If we find that > gut-poking is the only good way to write tests for a component, then I > would rather we revisit the design of the component instead of making it > mutable. Refactoring for testability is A-OK in my book. > > _______________________________________________ > > firefox-dev mailing list > > firefox-...@mozilla.org > > https://mail.mozilla.org/listinfo/firefox-dev > > — > Joe Hildebrand > > _______________________________________________ > firefox-dev mailing list > firefox-...@mozilla.org > https://mail.mozilla.org/listinfo/firefox-dev > _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
