[test] Add tests for cyclic arrays in Flight and Flight Reply

[everettbu]

Mirror of facebook/react#35347
Original author: unstubbable

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We already had tests for cyclic objects, but not for cyclic arrays.

[greptile-apps]

Greptile Overview

Greptile Summary

This PR adds test coverage for cyclic array structures in React Flight serialization. Two new tests were added that mirror the existing cyclic object tests:

• In ReactFlight-test.js: Tests that cyclic arrays can be transported through Flight's client-server communication
• In ReactFlightDOMReply-test.js: Tests that cyclic arrays can be properly encoded and decoded in Flight Reply

Both tests create an array that references itself (cyclic[1] = cyclic) and verify that the cyclic reference is preserved after serialization/deserialization. The tests follow the exact same patterns as the existing cyclic object tests, ensuring consistency in test coverage.

Confidence Score: 5/5

• This PR is safe to merge with no risk
• The changes are straightforward test additions that follow established patterns in the codebase. The new tests mirror existing cyclic object tests, use correct assertions to verify cyclic references are preserved, and add valuable coverage for array cycles alongside the existing object cycle tests. No implementation code is modified, only tests are added.
• No files require special attention

Important Files Changed

File Analysis

Filename	Score	Overview
packages/react-client/src/tests/ReactFlight-test.js	5/5	Added test for cyclic array transport, mirroring existing cyclic object test pattern with proper assertions for self-reference and shared object reference
packages/react-server-dom-webpack/src/tests/ReactFlightDOMReply-test.js	5/5	Added test for cyclic array encoding/decoding in Flight Reply, following the same pattern as existing cyclic object test with correct assertions

[greptile-apps]

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[everettbu]

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