GitHub Copilot Prompts & Custom Instructions

// Generate a {{language}} function that {{taskDescription}}
// Input: {{inputType}} — e.g. {{exampleInput}}
// Output: {{outputType}} — e.g. {{exampleOutput}}
// Constraints: {{constraints}}
// Style: use early returns, no nested ternaries

Write unit tests for the {{functionName}} function in #file:{{filePath}}.

Use {{testFramework}} with the following structure:
- Group tests by behavior (describe blocks)
- Cover: happy path, edge cases (empty input, null, boundary values), and error cases
- Use descriptive test names: "should {{expectedBehavior}} when {{condition}}"
- Mock {{dependenciesToMock}} using {{mockLibrary}}
- Assert both return values and side effects

Add comprehensive JSDoc documentation to every exported function in #file:{{filePath}}.

For each function include:
- @description — one sentence explaining what it does and why
- @param — each parameter with type and description
- @returns — what is returned and when
- @throws — any errors that can be thrown
- @example — one realistic usage example

Do not modify the function implementations. Preserve existing inline comments.

// REFACTOR: Extract the {{logicDescription}} below into a pure function
// called {{newFunctionName}}({{params}}): {{returnType}}
// Move to {{targetFile}}
// Reason: {{reason}}
// Keep the call site here, just replace inline logic with the function call

// Build a regex that matches {{patternDescription}}
// Valid examples: {{validExamples}}
// Invalid examples (should NOT match): {{invalidExamples}}
// Flags: {{flags}}
// Return as a named const with a JSDoc comment explaining the pattern

const {{regexName}}: RegExp = 

Create a typed API client for the {{apiName}} API in #file:{{filePath}}.

Requirements:
- Base URL: {{baseUrl}}
- Auth: {{authMethod}} ({{authDetails}})
- Endpoints to implement: {{endpoints}}
- Use fetch with proper error handling (throw typed errors)
- Add request/response TypeScript interfaces for each endpoint
- Include retry logic with exponential backoff (max {{maxRetries}} retries)
- Add JSDoc with example usage for each method

# .github/copilot-instructions.md

## Project: {{projectName}}
- Language: {{language}} ({{languageVersion}})
- Framework: {{framework}} ({{frameworkVersion}})
- Package manager: {{packageManager}}

## Coding Conventions
- Use {{namingConvention}} for variables and functions
- Prefer {{componentStyle}} components
- Error handling: {{errorHandlingPattern}}
- Always add return types to exported functions

## Testing
- Framework: {{testFramework}}
- File naming: {{testFilePattern}}
- Minimum coverage expectations: {{coverageExpectations}}

## Do NOT
- Use `any` type in TypeScript
- Use default exports (prefer named exports)
- Add comments that restate the code
- Import from relative paths when path aliases exist

I'm getting this error in #file:{{filePath}} at line {{lineNumber}}:

```
{{errorMessage}}
```

Context:
- This function is called by {{callerDescription}}
- The input data comes from {{dataSource}}
- It worked before {{whatChanged}}

Diagnose the root cause. Explain why it's happening, then provide a fix. If there are multiple possible causes, list them ranked by likelihood.