Summary:
Pull Request resolved: https://github.com/react/react-native/pull/57611
Directly follows D112733139 (Metro).
**Motivation**
- New Node builtins are *only* available under the prefix (e.g. `node:sqlite`), as this allows Node to introduce them without ecosystem-breaking changes, so this is the direction of travel and the only choice that'll allow consistency.
- Encouraging them and grouping them separately makes it easier to reason about a module's 3rd party dependencies.
Changelog: [Internal]
Reviewed By: robhogan
Differential Revision: D112803684
fbshipit-source-id: 40668d746a7151b3aa4800ff8af997902a18d198
Summary:
Pull Request resolved: https://github.com/react/react-native/pull/57443
The Fantom REPL (`yarn fantom-cli`) crashed on startup with `TypeError: Cannot read properties of undefined (reading 'loadConfig')`. `metro` is a CommonJS module that only provides named exports, so the default import `import Metro from 'metro'` resolves to `undefined` under the Babel interop used to run the REPL, and any access such as `Metro.loadConfig` throws.
Switch to a namespace import (`import * as Metro from 'metro'`), matching how metro is already imported in the Fantom global setup.
Changelog: [Internal]
___
Reviewed By: javache
Differential Revision: D110754395
fbshipit-source-id: f1c7c415f96a6adeb6dde12919983aa9a5a819a4
Summary:
Pull Request resolved: https://github.com/react/react-native/pull/57387
Adds `yarn fantom-cli`, an interactive REPL that evaluates JavaScript against the same native tester binary and Hermes runtime that Fantom tests run in. State persists across lines, input goes through Metro/Babel (so `import`, JSX and Flow all work), and the environment is set up the same way tests set it up — `React`, `ReactNative` and the `Fantom` API are available globally, so you can render surfaces and drive them interactively from the prompt.
The native tester gains an `--interactive` mode that loads a warm-up bundle without running tests and then evaluates length-prefixed snippets read from stdin, reporting results, console output and errors back as newline-delimited JSON. A Node driver hosts a Metro server, builds the warm-up bundle, spawns the binary, and bridges each line of input into the live runtime (top-level declarations persist across evaluations).
Features:
- Console-style output: results are printed with an inspector similar to the Chrome DevTools / Node.js consoles (nested objects/arrays up to a depth limit, quoted strings, functions/classes, `Map`/`Set`/`RegExp`/`Date`/`Error`, class instances, circular references, multi-line wrapping), colorized by type when stdout is a terminal. Inspecting a property never aborts the result or leaks into later evaluations: a property whose getter fails renders as `[Thrown: <error>]`, including getters that fail asynchronously through the runtime's global error handler (e.g. accessing a `react-native` export backed by a TurboModule that isn't registered).
- Autocompletion: pressing Tab completes global identifiers, in-scope bindings and object properties (property names are listed without invoking getters).
- Node-like CLI: with no arguments it starts the REPL; `-e <code>` evaluates a snippet and exits; a filename runs that script and exits. In the non-interactive modes the value of a trailing expression is not printed (use `console.log`) and a thrown error exits with a non-zero status code.
Also documents the REPL in the Fantom README.
Changelog: [Internal]
Reviewed By: javache, sammy-SC
Differential Revision: D110187712
fbshipit-source-id: 3e76c498ae04b8b1ce9e0e27e5ce6b6a0cd11e09
Alex Hunt