Prompt Library / Unit Test Writer / for Claude

Unit Test Writer Prompt for Claude

This is the Claude version of the unit test writer prompt: tests that cover the edge cases you would forget, not just the happy path. It is formatted the way Claude takes prompts best. Free — copy it, replace the bracketed parts, and paste it in.

The prompt

✎ Editable — click in, customize or extend this prompt, then copy. Your edits copy with it.Take this prompt into the Generator and customize it to your own specification →

Using this prompt with Claude

Claude follows structured prompts most reliably when the parts are wrapped in XML tags, which is why this version is formatted that way. Its long context window means you can paste large source text inside the tags without trimming.

Replace the bracketed placeholders — [PASTE THE FUNCTION OR CODE], [LANGUAGE AND TEST FRAMEWORK] — with your own details before pasting.

Other versions and customization

See all model versions of this prompt, or open the prompt gateway to build a custom prompt from your own one-line goal, formatted for Claude or any other model.

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