#1808 fix: tsdown overwrites "sta" bin command.

Recently I found that somehow "sta" command was gone from the npm registry even it exists in the code.

I've asked an AI for the investigation and found a cause, so here's the fix.
It seems tsdown can generate whole "exports" section as well, but I focused on fixing the "bin" section.

Here's the AI analysis

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Context

Starting with v13.12.1, the package published to npm no longer includes the sta command in the bin field — only swagger-typescript-api remains. Verified via npm view:

• swagger-typescript-api@13.12.0 → { "sta": "dist/cli.mjs", "swagger-typescript-api": "dist/cli.mjs" }
• swagger-typescript-api@13.12.1 … @13.12.4 (latest) → { "swagger-typescript-api": "dist/cli.mjs" }

The repo's package.json still declares both bins at every tag, so the source is not the problem — the published tarball is rewritten at publish time.

Root cause

1. package.json has "prepack": "tsdown", so tsdown runs right before npm pack/publish.
2. tsdown.config.ts sets exports: true, which lets tsdown's package-exports feature rewrite package.json.
3. v13.12.1 bumped tsdown 0.21.10 → 0.22.2. tsdown v0.22.0 added automatic bin generation: when exports.bin is unset, it scans entry chunks for a shebang, and if exactly one is found it overwrites the bin field with a single command named after the package (src/features/pkg/exports.ts in rolldown/tsdown: binName = pkg.name[0] === '@' ? … : pkg.name, return { [binName]: detected }).
4. index.ts (the CLI entry, bundled to dist/cli.mjs) starts with #!/usr/bin/env node — exactly one shebang chunk — so tsdown replaces the hand-written two-entry bin map with { "swagger-typescript-api": "./dist/cli.mjs" } in the packed tarball, silently dropping sta.

Fix

Edit tsdown.config.ts to configure bin explicitly instead of relying on shebang auto-detection:

export default defineConfig({
  entry: {
    index: "src/index.ts",
    cli: "index.ts",
  },
  dts: true,
  format: ["esm", "cjs"],
  sourcemap: true,
  exports: {
    bin: {
      sta: "./index.ts",
      "swagger-typescript-api": "./index.ts",
    },
  },
});

(Alternative: exports: { bin: false } also works — tsdown then leaves the manually-authored bin field untouched. The explicit map is preferred since it keeps tsdown as the single source of truth for the generated fields.)

Verification

1. bun install --frozen-lockfile && bun run build — confirm package.json bin still contains both sta and swagger-typescript-api after the build (tsdown rewrites it during build when exports is enabled).
2. npm pack --dry-run (or bun pm pack) and inspect the packed package.json to confirm both bin entries survive the prepack hook.
3. bun run test to make sure nothing else regressed.

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Summary by cubic

Restore the missing sta CLI by configuring tsdown to emit both bin commands and prevent overwrite during pack/publish. Both sta and swagger-typescript-api now install correctly.

• Bug Fixes
  • Set exports.bin in tsdown.config.ts to map sta and swagger-typescript-api to ./index.ts.
  • Removed bin from package.json so tsdown is the single source of truth and avoids the single-bin auto-detection in tsdown@0.22.x.
  • Added a changeset to release this as a patch.