Devtools disable log dimming strict mode setting

[everettbu]

Mirror of facebook/react#35207
Original author: emily8rown

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Summary

Currently, every second console log is dimmed, receiving a special style that indicates to user that it was raising because of React Strict Mode second rendering. This introduces a setting to disable this.

How did you test this change?

Test in console-test.js

Screen.Recording.2025-11-25.at.11.21.05.mov

Browser extension react devtools

Screen.Recording.2025-11-25.at.12.25.23.mov

React native dev tools:

Screen.Recording.2025-12-11.at.11.21.11.mov

[greptile-apps]

Greptile Overview

Greptile Summary

This PR adds a user-configurable setting to disable console log dimming for the second render in React Strict Mode. The implementation is thorough and well-integrated across the DevTools codebase.

Key Changes:

• Added disableSecondConsoleLogDimmingInStrictMode setting that prevents ANSI dimming codes from being applied to duplicate console logs in Strict Mode
• Setting is disabled by default, preserving existing behavior
• UI includes proper mutual exclusivity: when "Hide logs" is enabled, the dimming toggle is automatically disabled and grayed out
• Implementation covers both console patching paths: patchConsoleForStrictMode (log, info, group, groupCollapsed) and patchConsoleForErrorsAndWarnings (error, warn)
• Comprehensive test coverage validates both enabled and disabled states
• Documentation updated with new setting and default value

Confidence Score: 5/5

• This PR is safe to merge with no significant risks
• The implementation is clean, well-tested, and follows existing patterns throughout the codebase. All code paths are covered with comprehensive tests, the feature is opt-in with sensible defaults, and the UI properly handles state interactions between related settings. No logical errors, edge cases, or security concerns identified.
• No files require special attention

Important Files Changed

File Analysis

Filename	Score	Overview
packages/react-devtools-shared/src/hook.js	5/5	Added disableSecondConsoleLogDimmingInStrictMode setting that conditionally skips dimming logic in both patchConsoleForStrictMode and patchConsoleForErrorsAndWarnings functions
packages/react-devtools-shared/src/devtools/views/Settings/DebuggingSettings.js	5/5	Added UI checkbox for the new setting with proper state management and mutual exclusivity with hideConsoleLogsInStrictMode
packages/react-devtools-shared/src/tests/console-test.js	5/5	Added comprehensive tests verifying dimming is disabled when setting is enabled and remains active when disabled

[greptile-apps]

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[everettbu]

Upstream PR was closed or merged. Code is synced via branch mirror.