A Jest transformer, so StyleX components can be tested without Babel. Almost all of its substance is cache correctness: Jest caches transform output aggressively and this transformer's output depends on a native binary Jest cannot see.
Cache key: The digest Jest uses to decide whether it may replay a previous transform. It must move whenever the output could differ, which is why it takes in more than the file's contents. Avoid: hash, fingerprint, digest
Binary identity:
The size and mtime of the .node addon the compiler actually dlopen'd, read
out of require.cache, and folded into the cache key. The declared package
version is not enough during development: rebuilding the crate replaces the
binary in place without touching package.json, so nothing in the key moves and
Jest replays output from the previous build.
Avoid: version, build id, checksum
Guarded manifest read:
Reading @stylexswc/rs-compiler/package.json inside a try. That subpath is
not declared in an exports map, so it resolves only by legacy lookup — if the
package ever gains an exports map without it, an unguarded read would throw at
module evaluation and fail the entire Jest run for a cache-key ingredient.
Avoid: version lookup, require, import