Documentation should state that React preserves setState callback this context

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Assessment

Difficulty
2/5
Estimated time
1-3 hours
Newbie friendliness
65/100
Issue type
Documentation
Clarity
Mostly clear
Activity status
Quiet
Tech stack
javascript, react
Domain
documentation

Research direction

Start with the referenced ReactFiberUpdateQueue.js line to confirm how setState callbacks receive context, then locate the setState callback documentation in the React docs. Update the guidance to state the callback's this context and distinguish it from class methods used as event handlers.

Written by the indexing model from the issue text.

Description

I just recently found out that setState's callback calls with the correct this context per this line in the React source. Nowhere in the documentation is it stated that React internally calls callbacks with context. This should be made clear as many assume it doesn't, leading to unnecessary measures such as arrow functions, explicit binding, etc.

The lack of explicit documentation also creates confusion with other things that do require binding, such as traditional class methods used as event handlers.

Dominant language
JavaScript
Stars
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Forks
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Avg merge
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Merged PRs (30d)
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