fix: resolve JSON schema missing items error for polar chart dataTable

[xile611]

Summary

• Fix generate_polar_chart function's dataTable parameter JSON schema error
• Replace z.array(z.any()) with z.array(z.object({}).passthrough()) to generate valid schema with items property
• Replace deprecated .nonempty() with .min(1)
• Add type assertion in convertZodToJsonSchema to fix TypeScript type inference issue

Problem

The MCP server reported the following error when calling generate_polar_chart:

code: invalid_function_parameters; message: Invalid schema for function 'vchart-mcp-server_generate_polar_chart': In context=('properties', 'dataTable'), array schema missing items.

Solution

The z.array(z.any()) schema was generating an invalid JSON schema without the items property. By changing to z.array(z.object({}).passthrough()), the generated schema now correctly includes:

{
  "type": "array",
  "items": {
    "type": "object",
    "properties": {},
    "additionalProperties": true
  },
  "minItems": 1
}

Test plan

• Run pnpm build - builds successfully
• Run pnpm test - all 16 tests pass
• Verify generated JSON schema contains items property

🤖 Generated with Claude Code