Add support for structured outputs via response-schema-file parameter

[Copilot]

This PR implements support for OpenAI's structured outputs feature by adding a new optional response-schema-file parameter. This enables users to receive consistent, structured JSON responses from AI models while maintaining full backward compatibility.

✨ New Features

Structured Outputs Support

• New Input: response-schema-file - Path to a JSON Schema file for enforcing structured responses
• OpenAI Integration: Uses response_format with json_schema type for native structured output support
• Type Safety: Proper TypeScript typing with { [key: string]: unknown } for schema validation

Usage Example

- name: Get structured response
  id: ai-response
  uses: FidelusAleksander/prompt-action@v1
  with:
    prompt: 'Analyze this code and provide feedback'
    response-schema-file: '.github/schemas/code-analysis.json'

Example Schema File

{
  "type": "object",
  "properties": {
    "summary": {
      "type": "string",
      "description": "Brief summary of the analysis"
    },
    "issues": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "severity": {
            "type": "string",
            "enum": ["low", "medium", "high", "critical"]
          },
          "description": {
            "type": "string"
          },
          "line": {
            "type": "number"
          }
        },
        "required": ["severity", "description"]
      }
    },
    "score": {
      "type": "number",
      "minimum": 0,
      "maximum": 100
    }
  },
  "required": ["summary", "issues", "score"],
  "additionalProperties": false
}

🔧 Implementation Details

Core Changes

1. Updated action.yml - Added new optional response-schema-file input
2. Modified generateAIResponse() - Added optional schema parameter with proper typing
3. Enhanced main.ts - Added schema file reading, JSON parsing, and comprehensive error handling
4. OpenAI API Integration - Conditionally includes response_format when schema is provided

Error Handling

• ✅ Missing schema file validation
• ✅ Invalid JSON schema detection
• ✅ Comprehensive error messages
• ✅ Graceful fallback to normal operation when no schema provided

🧪 Testing

Added comprehensive test coverage with 22/22 tests passing and 100% code coverage:

• ✅ 7 new test cases for structured output functionality
• ✅ Backward compatibility tests - all existing workflows continue to work
• ✅ Error handling tests - missing files, invalid JSON, etc.
• ✅ Integration tests - real schema file usage validation
• ✅ TypeScript compilation - proper typing throughout

📚 Documentation

Updated README with:

• Complete usage examples and real-world scenarios
• JSON Schema examples for common use cases
• Advanced usage patterns combining features
• Updated inputs table with all parameters

🔒 Backward Compatibility

Zero breaking changes - this is a fully backward-compatible addition:

• All existing workflows continue to work unchanged
• New parameter is completely optional
• No modifications to existing API surface
• Existing tests continue to pass without changes

📁 Files Added

• .github/schemas/code-analysis.json - Example schema for code analysis
• .github/schemas/simple-response.json - Simple response schema example
• __tests__/test-schema.json - Schema file for integration testing

Fixes #84.

Warning

Firewall rules blocked me from connecting to one or more addresses

I tried to connect to the following addresses, but was blocked by firewall rules:

• img.shields.io
  • Triggering command: node /home/REDACTED/work/prompt-action/prompt-action/node_modules/.bin/make-coverage-badge --output-path ./badges/coverage.svg (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to my firewall allow list

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[FidelusAleksander]

Move schemas to tests directory

Add test case using a schema in .github/workflows/test-action.yml

[Copilot]

Move schemas to tests directory

Add test case using a schema in .github/workflows/test-action.yml

Done! I've moved the schemas to the __tests__ directory and added a test case using structured outputs in the workflow file. Commit: 46d2a85