Problem

String parameters containing numeric values were incorrectly converted to JSON numbers instead of remaining as strings when creating API requests. This caused playlist creation to fail when using numeric strings for names or descriptions.

Example issue:

api.createPlaylist(userId, "2025")
    .description("2025")
    .build()
    .execute()

Before (broken): {"name":2025,"description":2025} ❌
After (fixed): {"name":"2025","description":"2025"} ✅

Root Cause

In AbstractRequest.bodyParametersToJson(), the code attempted to parse all parameter values as JSON using JsonParser.parseString(). This converted:

• "2025" → 2025 (number)
• "123.45" → 123.45 (number)
• "true" → true (boolean)
• "null" → null (JSON null)

Solution

Modified bodyParametersToJson() to always treat parameter values as strings using jsonObject.addProperty(name, value) instead of attempting JSON parsing. This preserves the caller's intent when they explicitly pass string values.

Key changes:

• Removed JsonParser.parseString() attempt for parameter values
• Use addProperty() to ensure values remain as string primitives
• Added comprehensive test coverage for edge cases

Testing

• ✅ All existing tests pass (335 tests, 0 failures)
• ✅ New test cases verify numeric strings stay as strings
• ✅ Edge cases covered: decimals, booleans, null-like strings
• ✅ Manual verification of exact issue scenario

This change ensures string parameters always serialize as JSON strings, preventing API validation failures while maintaining backward compatibility.

Fixes #420.

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.