The eval CLI tests and the two example smoke scripts located tsx with a
fixed number of `..` segments, assuming a hoisted install directly above
the workspace. A git worktree has no local node_modules and resolves
upwards to the main checkout, and a non-hoisted install keeps
node_modules inside the workspace, so the path pointed at nothing:
spawnSync failed to launch and 12 tests reported `status: null` instead
of a CLI exit code.
Resolve `tsx/cli` through Node's own module resolution behind a shared
tests/helpers/tsx-cli.ts, and spawn it with process.execPath rather than
executing the node_modules/.bin shim, which is a .cmd wrapper on Windows
that spawnSync cannot launch without a shell. `.bin/tsx` already links
to the same dist/cli.mjs, so the spawned command is unchanged.
Contributors can now run the full core suite directly from a worktree
without hand-linking tsx.
Jack Chen