fix: expand @Query() DTO parameters into individual query parameters

[hyeonss0417]

Summary

Fixes #91

When using NestJS with @Query() decorator and a DTO class (without field name argument), the DTO properties are now properly expanded into individual OpenAPI query parameters with their JSDoc annotations.

Problem

Previously, when using @Query() with a DTO class like:

@Get()
async findAll(@Query() query: ListFoodQueryDto): Promise<PaginatedResponse<FoodDto>> {
  // ...
}

The generated OpenAPI spec would have a single query parameter with an empty schema:

{
  "parameters": [
    { "name": "query", "in": "query", "required": true, "schema": {} }
  ]
}

Solution

Now each DTO property is expanded into individual query parameters with proper types and JSDoc annotations:

{
  "parameters": [
    {
      "name": "nextToken",
      "in": "query",
      "required": false,
      "schema": { "type": "string" },
      "example": "eyJvZmZzZXQiOjAsImxpbWl0IjoyMH0="
    },
    {
      "name": "limit",
      "in": "query",
      "required": false,
      "schema": { "type": "number", "minimum": 1, "maximum": 100, "default": 20 }
    },
    {
      "name": "offset",
      "in": "query",
      "required": false,
      "schema": { "type": "number", "minimum": 0, "default": 0 }
    },
    {
      "name": "name",
      "in": "query",
      "required": false,
      "schema": { "type": "string" },
      "example": "홍길동"
    }
  ]
}

Changes

• types.ts: Add isDto flag to NestParameterMetadata to identify DTO query parameters
• parser.ts: Mark @Query() without field name argument as DTO (isDto: true)
• openapiGenerator.ts: Add buildPropertySchema function and expand DTO properties into individual query parameters with JSDoc annotations (@example, @minimum, @maximum, @default, etc.)
• Tests: Add test cases for @Query() DTO expansion

Testing

yarn test src/test/nestjs/schema.test.ts

All new tests pass:

• ✅ should expand @query() DTO into individual query parameters
• ✅ should not have a single "query" parameter for DTO

[github-actions]

LGTM 👍

[github-actions]

LGTM 👍