Bug 176227 – Speedometer: Reduce duplication in react-redux test

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Mathias Bynens]

The generated bundle includes the same `Object.assign` polyfill five or six times.

In the source code, we’re using object spread in six different places:

    $ grep -r '{\.\.\.' src
    src/components/Footer.spec.js:  renderer.render(<Footer {...props} />)
    src/components/Header.spec.js:  renderer.render(<Header {...props} />)
    src/components/MainSection.js:            <TodoItem key={todo.id} todo={todo} {...actions} />
    src/components/MainSection.spec.js:  renderer.render(<MainSection {...props} />)
    src/components/TodoItem.spec.js:    <TodoItem {...props} />
    src/components/TodoTextInput.spec.js:    <TodoTextInput {...props} />

At build time, Babel transpiles this down to `Object.assign`, relying on the polyfill.

We should find out why the polyfill is not deduplicated correctly.

[Mathias Bynens]

Created attachment 320122 [details]
Patch

[Addy Osmani]

It appears with the latest patch that the problem is no longer an issue (react-scripts may have discovered upstream that there were dupes caused by their build pipeline). The changes in the latest work here LGTM. Deferring to Ryosuke.

[Ryosuke Niwa]

Safari 10.1.2 (12603.3.8)

Patched:
35.0 ± 0.71
33.4 ± 1.0
35.2 ± 1.4
34.8 ± 0.8
36.4 ± 1.1
35.9 ± 0.77

Unpatched:
33.3 ± 2.6
35.4 ± 0.99
35.5 ± 0.84
36.0 ± 0.99
35.5 ± 2.4
35.3 ± 0.66

Chrome 61.0.3163.79

Patched:
44.6 ± 1.5
43.8 ± 1.6
41.0 ± 3.2
43.5 ± 1.9
43.7 ± 1.8
44.7 ± 1.3

Unpatched:
43.8 ± 3.7
44.1 ± 1.5
46.3 ± 1.8
45.6 ± 1.6
46.3 ± 2.4
45.5 ± 1.4

[Ryosuke Niwa]

Comment on attachment 320122 [details]
Patch

r=me

[WebKit Commit Bot]

Comment on attachment 320122 [details]
Patch

Clearing flags on attachment: 320122

Committed r221841: <http://trac.webkit.org/changeset/221841>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Radar WebKit Bug Importer]

<rdar://problem/34693898>