Dual-format Output

Once tship is activated, it compiles your TypeScript source into two formats simultaneously.

How It Works

For each format, a separate TypeScript program is created with the appropriate module setting:

• CJS: module: CommonJS
• ESM: module: ESNext (always produces import/export)

The output directories are determined by the configuration rules described in the Configuration guide.

Folder Sharing and Extensions

If both formats share the same output directory (e.g., you set compilerOptions.outDir without tship.outDirs), tship will rename files to use distinct extensions:

• CJS → .cjs and .d.cts
• ESM → .mjs and .d.mts

If directories are separate, files keep the standard .js and .d.ts extensions.

When tship is not active

If no tship configuration is present, tship compiles a single output exactly like tsc. No renaming or dual-format logic is applied.