[noop] Fix createContainer argument order in the Fiber implementation

[everettbu]

Mirror of facebook/react#35945
Original author: eps1lon

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...and fix most of the type issues in the Fiber implementation of react-noop-renderer

Stacked on react/react#35944

Only addressed the most obvious issues. There's still some issues relating to loosely accessing object properties but those don't feel urgent. Especially because this is a test-only renderer.

The argument order of createContainer was the main concern.

[greptile-apps]

Greptile Summary

This PR fixes the createContainer argument order in the noop renderer's createLegacyRoot (where isStrictMode and concurrentUpdatesByDefaultOverride were swapped) and adds comprehensive Flow type checking support for react-noop-renderer.

• Argument order fix: In createLegacyRoot, the isStrictMode (boolean) and concurrentUpdatesByDefaultOverride (null | boolean) arguments to createContainer were in the wrong order — now corrected to match the reconciler's function signature
• New noop host config modules: Type definitions and shim modules extracted from createReactNoop.js into dedicated files (ReactFiberConfigNoop.js, ReactFiberConfigNoopHydration.js, etc.), following the same pattern used by other renderers
• New fork config shims: Added *.noop.js fork files for ReactFiberConfig, ReactFizzConfig, ReactFlightServerConfig, ReactFlightClientConfig, and ReactServerStreamConfig to enable proper Flow type checking
• Flow integration: Removed the blanket Flow ignore for react-noop-renderer and added a proper noop entry in inlinedHostConfigs.js so Flow can now type-check the noop renderer
• Host config restructuring: createReactNoop.js now splits the host config into sharedHostConfig, mutationHostConfig, and persistenceHostConfig objects, composed at the end based on the useMutation flag
• Jest setup consolidation: Moved the persistent renderer mock from setupTests.persistent.js and setupTests.xplat.js into setupHostConfigs.js to reduce duplication
• Type corrections: Fixed Segment.children type in ReactNoopServer.js from a single element to an array (matching actual usage), added Thenable import in Flight client, and added numerous $FlowFixMe suppressions for known type gaps

Confidence Score: 4/5

• This PR is safe to merge — it's a test-only renderer with type fixes and the argument order correction is verified against the reconciler's function signature.
• The changes are well-structured: the createContainer argument order fix in createLegacyRoot is clearly correct when compared to the reconciler's function signature, the new config modules follow established patterns from other renderers, and the host config restructuring is a clean refactor. The numerous $FlowFixMe suppressions indicate remaining type gaps but the PR description explicitly acknowledges this as intentional ("Only addressed the most obvious issues"). The noop renderer is test-only infrastructure, limiting blast radius. Score is 4 rather than 5 due to the volume of $FlowFixMe suppressions that represent deferred type safety work.
• packages/react-noop-renderer/src/createReactNoop.js deserves the most attention as the core file with the argument order fix and structural refactoring.

Important Files Changed

Filename	Overview
packages/react-noop-renderer/src/createReactNoop.js	Core file: fixes createContainer argument order in createLegacyRoot (isStrictMode/concurrentUpdatesByDefaultOverride swap), extracts types to shared modules, restructures host config into shared/mutation/persistence sections, adds comprehensive Flow type annotations.
packages/react-noop-renderer/src/ReactFiberConfigNoop.js	New file: central type definitions (Container, Instance, TextInstance, etc.) and re-exports from sub-config modules for noop renderer.
packages/react-reconciler/src/forks/ReactFiberConfig.noop.js	New file: noop fork config shim for the reconciler, re-exports from ReactFiberConfigNoop and bridges $$$config to module exports.
scripts/shared/inlinedHostConfigs.js	Adds new 'noop' inlined host config entry with proper entry points and paths for Flow type checking.
scripts/flow/config/flowconfig	Removes the Flow ignore for react-noop-renderer since it now has its own proper inlined host config entry.
scripts/jest/setupHostConfigs.js	Consolidates persistent mock setup into setupHostConfigs.js, removing duplication from setupTests.persistent.js and setupTests.xplat.js.
packages/react-noop-renderer/src/ReactNoopFlightClient.js	Adds multiple $FlowFixMe suppressions for type issues discovered during noop typechecking; adds Thenable import.
packages/react-noop-renderer/src/ReactNoopFlightServer.js	Adds $FlowFixMe suppressions, widens Destination type to include strings alongside Uint8Array.
packages/react-noop-renderer/src/ReactNoopServer.js	Fixes Segment.children type from single element to Array, fixes Placeholder.parent to include Segment, adds multiple $FlowFixMe suppressions.
packages/react-reconciler/src/tests/ViewTransitionReactServer-test.js	Changes test gate from 'enableViewTransition

_{Last reviewed commit: fe1ec4f}

[greptile-apps]

_{30 files reviewed, no comments}

_{Edit Code Review Agent Settings | Greptile}

[everettbu]

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