Coding Prompts

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)

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

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

Common Problems & Fixes

• Unstable output: Add length/format constraints, fix field order
• Missing edge cases: Explicitly list edge cases, require coverage
• Code doesn't run: Provide more complete context and dependency versions
• Inconsistent style: Specify lint rules or existing style guide

Index

• /learn/prompt-master/prompt-coding-code-snippet
• /learn/prompt-master/prompt-coding-mysql-query
• /learn/prompt-master/prompt-coding-tikz