Internal AST-manipulation primitives shared across Cloudflare Workers SDK codemods.

This package wraps recast with a small set of helpers (parseJs, parseTs, parseFile, transformFile, mergeObjectProperties) used by C3 and autoconfig to transform user project files. It is private and not published.

Writing codemods often requires trial and error. The package ships a dedicated dev workflow so you can iterate on transforms in isolation without writing throw-away scripts.

1. Edit dev-snippets/test.ts — put whatever source code you want to transform into this file. It is the default input used by the dev script. You can add more files under dev-snippets/ and reference them from src/dev.ts.

2. Edit testCodemod() in src/dev.ts — this is your sandbox. Call testTransform() with the path to your snippet and a recast visitor that describes the transform:

   const testCodemod = () => {
   	testTransform("../dev-snippets/test.ts", {
   		visitIdentifier(n) {
   			n.node.name = "MyNewName";
   			return false;
   		},
   	});
   };

3. Run pnpm dev — the transformed code is printed to the console and written to dev-snippets-outputs/test.ts (gitignored). Inspect the output file to verify the transform behaves as expected.

Mirrors the production transformFile() API but instead of silently writing in place it:

• Prints the transformed source to the console
• Writes the result to the corresponding path under dev-snippets-outputs/

The filePath argument must point to a file inside dev-snippets/; paths outside that directory are rejected.