Stop Mutating Merged Lifecycle Results #2246
Closed
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
|
Perhaps worth calling it |
| ); | ||
|
|
||
| mapObject(two, function(value, key) { | ||
| forEachObject(two, function(value, key) { | ||
| invariant( | ||
| one[key] === undefined, |
There was a problem hiding this comment.
Hmm... shouldn't this be !(key in one)? Keys with the value of undefined have feelings, too.
There was a problem hiding this comment.
It should be hasOwnProperty, I guess.
yungsters
force-pushed
the
master
branch
2 times, most recently
from
4e27826 to
d6ba0da
Compare
|
Revised without |
|
Perhaps it's too performance sensitive to justify it, but wouldn't it make sense to use |
|
See #2464 (which coincidentally has the same numbers as this pull request, but shuffled). |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Summary:
Currently,
ReactCompositeComponentmutates values returned bygetDefaultProps,getInitialState, andgetChildContext. This is bad because the objects may, for example, be cached and re-used across instances of a React component.This changes
ReactCompositeComponentto instead create a new object. In return for allocating a new object, I've replacedmapObjectwithforEachObjectso that we are no longer allocating an unused object.Fair trade, IMO.
Test Plan:
Ran unit tests successfully: