Refactor TypeScript Code with Claude Code CLI

What you’ll get

You will refactor your TypeScript codebase to adopt a new JobDefinition.create method and remove outdated logging statements. This approach leverages AI to automate repetitive code updates, saving you time and reducing the risk of manual errors.

Tools you need

• Claude Code CLI (paid) - An AI assistant for code understanding and modification.
• VSCode (free) - A popular code editor where you can run the Claude Code CLI and view your code.

Steps

1. Prepare your environment - Ensure you have VSCode installed and the Claude Code CLI set up according to its documentation. Open your TypeScript project in VSCode.

2. Initiate the refactoring prompt - Use the Claude Code CLI to interact with the AI. Paste the following prompt, replacing the bracketed text with your specific details:

   I have modified the type signature and behaviour of how jobs are created. Previously, job definition create took a batch argument (created from a queue). Now it takes the queue directly, is async, requires the databaseClient to be passed in at creation (vs. when the batch is executed). It no longer returns anything - which is fine because the result was only being used for logging - which is now done for us so we don't have to worry. Can we refactor the codebase to make use of the new JobDefinition.create? Remove the vestigial "Job created" log please.
   
   Perform this task and this task only. If you see something unrelated that you believe needs to be refactored - DO NOT MODIFY IT. ONLY PERFORM ACTIONS DIRECTLY RELEVANT TO THIS TASK

   You should see the Claude Code CLI begin to process your request, potentially listing files it intends to modify.

3. Review the proposed changes - After the AI has analyzed your codebase and identified the necessary changes, carefully review the modifications. VSCode’s diff viewer will highlight additions, deletions, and changes. Pay close attention to ensure only the intended refactoring is occurring.

4. Accept or reject changes - Based on your review, accept the changes if they align with your requirements. If the AI has made unintended modifications (like reordering object keys or altering unrelated logs), you may need to reject those specific changes or refine your prompt for a subsequent attempt.

5. Verify the refactored code - Once you have accepted the relevant changes, run your project’s tests or manually inspect the affected areas of the code to confirm that the JobDefinition.create method is being used correctly and that the vestigial logging has been removed.

Original source

This workflow is based on a question and discussion posted on Hacker News by user tlonny, seeking advice on issues encountered while using AI agents for code refactoring tasks.

Notes & variations

• Cost and free alternative: Claude Code requires a paid Claude plan or API credits. If you need a free option, the Gemini CLI has a generous free tier and handles the same refactoring task.
• Common pitfall: Be wary of AI agents making unintended changes, such as reordering code elements or modifying unrelated sections. The prompt includes a specific instruction to prevent this, but vigilant review is still crucial.
• Tip for better results: If the AI struggles to understand the context or makes errors, try breaking down the refactoring into smaller, more specific requests. You can also provide more context about the JobDefinition.create method’s new signature and expected behavior.