You get:
- functions missing JSDoc comments (hard to maintain)
- no type checking (TypeScript would catch errors)
- poor error handling (crashes on edge cases)
- inconsistent naming conventions
- functions that work but aren’t reusable
But a function is not just code.
It is a reusable unit with documentation, type safety, and error handling.
- JSDoc: what it does, params, returns, throws
- Parameter validation: check types and presence
- Error handling: try/catch for edge cases
- Default parameters: sensible defaults where appropriate
Without documentation and error handling, functions are fragile.
This framework forces AI to generate production-ready JavaScript functions.
Assume the role of a senior JavaScript developer who writes clean, documented, production-ready functions. Your task is to generate a JavaScript function from a natural language description. Generate: 1. FUNCTION SIGNATURE - Function name (descriptive, camelCase) - Parameters with default values - Return type (in JSDoc) 2. JSDOC COMMENT - Brief description - @param for each parameter (type and description) - @returns description - @throws for error conditions 3. FUNCTION BODY - Parameter validation - Main logic - Error handling (try/catch) 4. EXAMPLE USAGE - How to call the function - Expected output 5. UNIT TEST (Jest or Mocha) - Test normal case - Test edge case - Test error case INPUTS: Function Description: [WHAT SHOULD THE FUNCTION DO?] Input Parameters (names and types): [LIST] Return Value (type and description): [DESCRIBE] Edge Cases to Handle (if any): [LIST] Error Conditions to Handle: [E.G., "Invalid input," "Empty array," "Network error"] Environment: [NODE.JS / BROWSER / BOTH] RULES: - Use camelCase for function names - Include JSDoc comments for all public functions - Validate parameters (check types, presence) - Handle edge cases gracefully (don't crash) - Use const/let (not var) - Use arrow functions where appropriate - Add try/catch for async operations
- Be specific about parameter types (string, number, array of objects).
- List edge cases you know will happen (null, undefined, empty arrays).
- The generated unit test is a starting point — expand it with your own cases.
- Run the function through ESLint after generation.
- Add TypeScript types if your project uses TypeScript.
Function Description: Calculate the average of an array of numbers. Return 0 if the array is empty.
Input Parameters: numbers (array of numbers)
Return Value: number (the average)
Edge Cases to Handle: Empty array, array with one item, array with negative numbers
Error Conditions to Handle: If input is not an array, throw TypeError
Environment: NODE.JS
This framework improves outcomes by forcing:
- JSDoc comments (maintainability)
- parameter validation (robustness)
- error handling (resilience)
- unit tests (correctness)
- example usage (usability)
Great JavaScript functions don’t just work — they’re documented, tested, and handle errors gracefully.
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