From bfa56d60533cce4d9a3e93b0cfe979059958a15c Mon Sep 17 00:00:00 2001
From: Ko Yamaura <ko.foot1103@gmail.com>
Date: Tue, 18 Mar 2025 08:10:48 +0900
Subject: [PATCH 1/2] feat: add TypedApiParam decorator and corresponding tests

---
 src/decorators/index.ts                       |  1 +
 .../typed-api-param.decorator.spec.ts         | 50 +++++++++++++++++++
 src/decorators/typed-api-param.decorator.ts   | 14 ++++++
 3 files changed, 65 insertions(+)
 create mode 100644 src/decorators/typed-api-param.decorator.spec.ts
 create mode 100644 src/decorators/typed-api-param.decorator.ts

diff --git a/src/decorators/index.ts b/src/decorators/index.ts
index b71c5e9..57e6059 100644
--- a/src/decorators/index.ts
+++ b/src/decorators/index.ts
@@ -1 +1,2 @@
 export * from './api-paginated-response.decorator';
+export * from './typed-api-param.decorator';
diff --git a/src/decorators/typed-api-param.decorator.spec.ts b/src/decorators/typed-api-param.decorator.spec.ts
new file mode 100644
index 0000000..e0d8307
--- /dev/null
+++ b/src/decorators/typed-api-param.decorator.spec.ts
@@ -0,0 +1,50 @@
+import { Controller, Get } from '@nestjs/common';
+import { DECORATORS } from '@nestjs/swagger/dist/constants';
+import { ApiProperty } from '@nestjs/swagger';
+import { TypedApiParam } from './typed-api-param.decorator';
+
+describe('TypedApiParam', () => {
+  describe('classのmethodに設定された場合', () => {
+    class UserDto {
+      @ApiProperty({ required: true })
+      id: string;
+
+      @ApiProperty({ required: true })
+      name: string;
+    }
+
+    @Controller('tests')
+    class TestUserController {
+      @TypedApiParam<UserDto>({
+        name: 'id',
+        type: 'string',
+        description: 'User ID',
+      })
+      @Get(':id')
+      public get(): UserDto {
+        return { id: '1', name: 'test' };
+      }
+    }
+
+    it('メソッドにmetadataが設定されている', () => {
+      const controller = new TestUserController();
+      expect(
+        Reflect.hasMetadata(DECORATORS.API_PARAMETERS, controller.get),
+      ).toBeTruthy();
+
+      const metadata = Reflect.getMetadata(
+        DECORATORS.API_PARAMETERS,
+        controller.get,
+      );
+      expect(metadata).toEqual([
+        {
+          name: 'id',
+          type: 'string',
+          description: 'User ID',
+          in: 'path',
+          required: true,
+        },
+      ]);
+    });
+  });
+});
diff --git a/src/decorators/typed-api-param.decorator.ts b/src/decorators/typed-api-param.decorator.ts
new file mode 100644
index 0000000..a50c832
--- /dev/null
+++ b/src/decorators/typed-api-param.decorator.ts
@@ -0,0 +1,14 @@
+import { ApiParam, ApiParamOptions } from '@nestjs/swagger';
+
+/**
+ * nestjs swaggerの @ApiParam をラッピングしたdecorator
+ * GenericsでDTOクラスを受け取り、そのkeyをApiParamのnameに型づけする
+ *
+ * @param options Swagger parameter options with typed name property
+ * @returns Decorator function
+ */
+export const TypedApiParam = <T extends object>(
+  options: ApiParamOptions & { name: keyof T },
+) => {
+  return ApiParam({ ...options });
+};

From 27aaaf5dd70ce99d26295519fc741f4020a96f12 Mon Sep 17 00:00:00 2001
From: Ko Yamaura <ko.foot1103@gmail.com>
Date: Tue, 18 Mar 2025 08:35:49 +0900
Subject: [PATCH 2/2] docs: update README to include NestJS Decorators section
 with TypedApiParam example

---
 README.md | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/README.md b/README.md
index d4ecf34..e32ecf5 100644
--- a/README.md
+++ b/README.md
@@ -9,6 +9,7 @@ This library has following features.
 - Logger
 - Result
 - some utils
+- NestJS Decorators
 
 ## 🚀 Getting Started
 
@@ -91,6 +92,37 @@ const result = await toResultAsync(promise);
 console.log(result.isFailure()); // true
 ```
 
+### NestJS Decorators
+
+#### TypedApiParam
+
+The TypedApiParam decorator is a type-safe wrapper around NestJS Swagger's @ApiParam decorator. It allows you to specify route parameters with type checking based on your DTO classes.
+
+```typescript
+import { Controller, Get } from '@nestjs/common';
+import { TypedApiParam } from '@plugoinc/common';
+
+class UserDto {
+  id: string;
+  name: string;
+}
+
+@Controller('users')
+class UserController {
+  @TypedApiParam<UserDto>({
+    name: 'id',
+    type: 'string',
+    description: 'User ID',
+  })
+  @Get(':id')
+  getUser(@Param() params: UserDto) {
+    // Implementation
+  }
+}
+```
+
+By using TypedApiParam, you get type checking for the `name` property, ensuring it matches a property from your DTO class.
+
 ## 🪪 License
 
 MIT