Claude prompt for code generation: Type Narrowing (Common Fixes)
Claude · Code Generation · Common Fixes
You are a hands-on practitioner using Claude for code generation, specifically type narrowing.
Job: make invalid hard.
Audience: ts/python. Constraint: examples.
Working style: diagnostic. Optimize for typical failures and how to repair the prompt.
Process:
1. Restate the brief in one sentence and list missing facts as questions.
2. Draft the artifact.
3. Stress-test it against the constraint.
4. Return a final version plus 3 numbered improvements.
Output contract: use headings, short paragraphs, and concrete examples. No filler. No invented statistics.
If information is missing, make the smallest reasonable assumption and label it.Use this Claude code generation template when ts/python need type narrowing with the rule: examples. Most failed runs trace back to missing audience or success criteria — this prompt adds both. The common fixes version uses diagnostic language and targets typical failures and how to repair the prompt.
When to use this prompt
For Anthropic models, code generation prompts fail when they mix strategy and execution. This type narrowing brief separates the job so you can iterate once, not ten times. Pair it with a real sample from your portfolio for best results.
Why this prompt works
- Names a clear job so Claude does not wander into generic advice.
- The common fixes angle adds typical failures and how to repair the prompt without extra fluff.
- Forces an output contract: headings, examples, and a final version.
- Locks the audience (ts/python) before style so tone stays honest.
- Uses diagnostic language that matches how practitioners actually brief work.
How to use it in Claude
Paste the prompt into Claude and replace bracketed details with your facts. Save the winning variant for type narrowing — teams with a short library ship faster. Ask for a shorter version after the long one; compression reveals weak claims. Add one real example from your last week of work so the model mirrors your domain. If the first answer is vague, reply with the constraint again: examples.
Swap the audience once. If the type narrowing piece still works, the core is solid. For type narrowing in code generation, the failure mode is usually no example. This prompt blocks that by design — especially "examples". Expect two minutes customizing and two minutes editing for Common Fixes output. Anthropic models still need your facts for type narrowing; they cannot invent metrics or brand rules. developers teams bookmark slug type-narrowing-fixes when typical failures and how to repair the prompt matters.
Step-by-step
- Open Claude and paste the prompt block unchanged.
- Replace placeholders with your project facts (ts/python, offer, timeline).
- Confirm the constraint is still visible: examples.
- If output is vague, ask Claude to restate assumptions as questions first.
- Reply with one fix list, then regenerate the final version only.
Example output
Example output shape: H1 with Type Narrowing, 3 short sections, bullet list of recommendations, closing line that states examples. Facts you supply appear; nothing invented.
Common mistakes
- Accepting the first draft without checking make invalid hard.
- Using the Common Fixes prompt but editing it into a vague one-liner.
- Pasting confidential data instead of redacted placeholders.
Expert notes
Slug type-narrowing-fixes: a developers-oriented code generation brief. Functions, refactors, tests, and architecture sketches. Pair it with one real asset from your portfolio before the second run.
Refresh quarterly: Claude models change. Keep constraints; update examples. Mark the page stale if examples no longer matches policy.
Comparison / variations
| Approach | When | Tweak |
|---|---|---|
| Bare request | You only need a spark | Write a type narrowing piece. |
| This prompt | You need a usable draft | Role, constraint, steps, and output contract included. |
| Plus examples | Voice must match yours | Paste 120 words of your writing or a still you like, then rerun in Claude. |
Key takeaways
- Claude improves when you paste a real snippet or reference still.
- Code Generation work needs functions, refactors, tests, and architecture sketches.
- If text output drifts, re-anchor with examples.
- The Common Fixes variant is for typical failures and how to repair the prompt.
- Keep examples visible in the prompt, not only in your head.
FAQ
- What is a Claude prompt for type narrowing?
- It is a structured brief that tells Claude how to produce code generation output for ts/python. This common fixes version stresses typical failures and how to repair the prompt and keeps "examples" in the instructions.
- How do I customize this Claude code generation prompt?
- Swap project nouns, paste one real example, and leave the process steps intact. The constraint "examples" should stay unless your brief truly changed.
- Why use the common fixes angle for type narrowing?
- Different angles solve different failures. Common Fixes helps when ts/python need typical failures and how to repair the prompt. It is not longer for its own sake — each line has a job.
- Is this Claude prompt updated for 2026?
- Yes. Pages follow our SEO Bible, refresh on a rolling schedule, and include current best practices for Anthropic models. Always verify facts before client delivery.