focal Fix double re-render in LiftWrapper and migrate it to PureComponent

Fix double re-render in LiftWrapper and migrate it to PureComponent

Open KatSick opened this issue 3 years ago • 1 comments

what was done:

migrate LiftWrapper to PureComponent
move LiftWrapper logic to namespace
slight refactor Render{One,Many}
eliminate double re-render (because of setState)
bonus: added focal bench to https://github.com/krausest/js-framework-benchmark/pull/889

Context

In the previous LiftWrapper, we used setState method to re-render our component when we subscribe to new props AND initially render our component. As an example: during the very first render, we start rendering our renderCache as null and then synchronously re-render it via setState . Since by design Focal does need sync observable emit, I optimized first render to render initial observable value without invoking setState reconciliation (via refs).

todo before merge:

[x] add MR description about the issue and the fix (and change title)
[x] [not that easy :(]add unit tests for re-renders (currently only renderToStaticMarkup is in unit-tests)
[x] [no results] investigate, how to test "waste render" in react via unit-tests (see screenshots)
[x] perform benchmarks
[x] [it works, but hard to compare values between runs, since they are too small and there is a lot of deviatiosn] investigate elm benchmark