How React Native Testing Library is different from Native Testing Library

The speaker says the libraries have similar APIs but work differently under the hood. React Native Testing Library came first; the official Testing Library version was created later. After discussions with Kent, the creator of Testing Library, the teams kept both libraries.

The speaker describes React Native Testing Library as community-driven and developed by Callstack. It aims to keep a thin layer over React Test Renderer and leave fixes for React Native APIs to React Native itself. The other library adds workarounds for issues such as broken native mocks, which the speaker says has contributed to maintenance problems.

Version one included shallow rendering and some unsafe queries that did not follow Testing Library's guiding principles. Because many users, including Callstack clients, depended on those APIs, the team planned gradual changes rather than breaking compatibility at once. Version two, released a few weeks before the conversation, removed or renamed some risky APIs and added compatibility with community ESLint tools and custom Jest matchers.

The speaker says few upgrade problems had been reported in the weeks after version two, which they took as a sign that users could migrate gradually. The release also prompted renewed discussion with Kent about resolving the split. The speaker says React Native Testing Library might become the single library, with the other phased out, once a migration strategy is in place.