Coding Prompts

Code generation prompts (overview)

This section collects code generation prompts. The point isn't "let AI write all the code" -- it's about turning prompts into a repeatable interface (clear input + constraints + output format) for better control and reusability.

Use Cases

Quickly generate boilerplate code or scaffolding
Turn natural language requirements into executable code
Fix bugs, add edge case handling, or add logging
Generate test cases, align interface formats

Core Structure (include these every time)

Goal: What functionality to build
Context: Language version, framework, constraints, existing code
Input: Data structures, examples, edge cases
Output: Format, file location, function signature

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Prompt Template (General)

You are a senior engineer. Implement the following:

Goal:
- {{WHAT_TO_BUILD}}

Context:
- Language: {{LANG_VERSION}}
- Framework: {{FRAMEWORK}}
- Style: {{STYLE_OR_GUIDE}}
- Constraints: {{CONSTRAINTS}}

Input:
{{INPUT_SPEC}}

Output:
- Code only
- Must include {{FUNCTION_NAME}}
- Keep existing API unchanged

Example 1: Generate a Function

You are a senior frontend engineer. Implement a function in TypeScript.

Goal:
- Group a user list by age

Context:
- Language: TypeScript 5
- Constraints: Pure function, don't mutate the original array

Input:
type User = { id: string; name: string; age: number }
const users: User[] = [...]

Output:
- Function name: groupByAge
- Returns Record<number, User[]>
- Code only

Example 2: Fix a Bug

You are a senior backend engineer. Fix the code below and explain why.

Problem:
- Throws an error when amount is 0
- Precision issue: 0.30000000000004

Context:
- Node.js 20
- Cannot add new dependencies

Code:
function calcTotal(items) {
  return items.reduce((sum, item) => sum + item.amount, 0);
}

Output:
- Fixed code
- 3 or fewer lines of explanation

Example 3: Generate Test Cases

You are a senior test engineer. Write unit tests for the function below.

Context:
- Testing: Jest
- Cover normal input, empty array, invalid input

Code:
export function normalizeEmail(email: string) {
  return email.trim().toLowerCase();
}

Output:
- Jest test code

Prompt 大师