feat(@ApiExtension): When used on a controller it applies to all methods

e2e/api-spec.json

@@ -403,7 +403,7 @@
           "create cats"
         ],
         "x-foo": {
-          "test": "bar "
+          "from-method": "bar"
         }
       },
       "get": {
@@ -646,6 +646,9 @@
             "source": "console.log('Hello World');"
           }
         ],
+        "x-foo": {
+          "from-controller": true
+        },
         "x-multiple": {
           "test": "test"
         }
@@ -725,7 +728,10 @@
         ],
         "tags": [
           "cats"
-        ]
+        ],
+        "x-foo": {
+          "from-controller": true
+        }
       }
     },
     "/api/cats/{id}": {
@@ -806,7 +812,10 @@
         "tags": [
           "cats"
         ],
-        "x-auth-type": "NONE"
+        "x-auth-type": "NONE",
+        "x-foo": {
+          "from-controller": true
+        }
       }
     },
     "/api/cats/explicit-query": {
@@ -1025,7 +1034,10 @@
         ],
         "tags": [
           "cats"
-        ]
+        ],
+        "x-foo": {
+          "from-controller": true
+        }
       }
     },
     "/api/cats/bulk": {
@@ -1101,7 +1113,10 @@
         "summary": "Find all cats in bulk",
         "tags": [
           "cats"
-        ]
+        ],
+        "x-foo": {
+          "from-controller": true
+        }
       },
       "post": {
         "operationId": "CatsController_createBulk",
@@ -1169,7 +1184,10 @@
         ],
         "tags": [
           "cats"
-        ]
+        ],
+        "x-foo": {
+          "from-controller": true
+        }
       }
     },
     "/api/cats/as-form-data": {
@@ -1255,7 +1273,10 @@
         "summary": "Create cat",
         "tags": [
           "cats"
-        ]
+        ],
+        "x-foo": {
+          "from-controller": true
+        }
       }
     },
     "/api/cats/wildcard/{path}": {
@@ -1312,7 +1333,10 @@
         ],
         "tags": [
           "cats"
-        ]
+        ],
+        "x-foo": {
+          "from-controller": true
+        }
       }
     },
     "/api/cats/with-enum/{type}": {
@@ -1382,7 +1406,10 @@
         ],
         "tags": [
           "cats"
-        ]
+        ],
+        "x-foo": {
+          "from-controller": true
+        }
       }
     },
     "/api/cats/with-enum-named/{type}": {
@@ -1449,7 +1476,10 @@
         ],
         "tags": [
           "cats"
-        ]
+        ],
+        "x-foo": {
+          "from-controller": true
+        }
       }
     },
     "/api/cats/with-random-query": {
@@ -1528,7 +1558,10 @@
         ],
         "tags": [
           "cats"
-        ]
+        ],
+        "x-foo": {
+          "from-controller": true
+        }
       }
     },
     "/api/cats/download": {
@@ -1587,7 +1620,10 @@
         "summary": "",
         "tags": [
           "cats"
-        ]
+        ],
+        "x-foo": {
+          "from-controller": true
+        }
       }
     },
     "/api/cats/raw-schema-response": {
@@ -1676,7 +1712,10 @@
         ],
         "tags": [
           "cats"
-        ]
+        ],
+        "x-foo": {
+          "from-controller": true
+        }
       }
     }
   },
@@ -2076,12 +2115,12 @@
             ]
           }
         },
-        "x-schema-extension-multiple": {
-          "test": "test"
-        },
         "x-schema-extension": {
           "test": "test"
         },
+        "x-schema-extension-multiple": {
+          "test": "test*2"
+        },
         "required": [
           "name",
           "age",

e2e/src/cats/cats.controller.ts

@@ -39,6 +39,7 @@ import { CatBreed } from './enums/cat-breed.enum';
   description: 'Test',
   schema: { default: 'test' }
 })
+@ApiExtension('x-foo', { 'from-controller': true })
 @Controller('cats')
 export class CatsController {
   constructor(private readonly catsService: CatsService) {}
@@ -74,7 +75,7 @@ export class CatsController {
     type: () => Cat
   })
   @ApiResponse({ status: 403, description: 'Forbidden.' })
-  @ApiExtension('x-foo', { test: 'bar ' })
+  @ApiExtension('x-foo', { 'from-method': 'bar' })
   async create(@Body() createCatDto: CreateCatDto): Promise<Cat> {
     return this.catsService.create(createCatDto);
   }

e2e/src/cats/classes/cat.class.ts

@@ -2,7 +2,7 @@ import { ApiExtension, ApiProperty } from '../../../../lib';
 import { LettersEnum } from '../dto/pagination-query.dto';
 
 @ApiExtension('x-schema-extension', { test: 'test' })
-@ApiExtension('x-schema-extension-multiple', { test: 'test' })
+@ApiExtension('x-schema-extension-multiple', { test: 'test*2' })
 export class Cat {
   @ApiProperty({ example: 'Kitty', description: 'The name of the Cat' })
   name: string;

e2e/validate-schema.e2e-spec.ts

@@ -146,7 +146,7 @@ describe('Validate OpenAPI schema', () => {
       ).toEqual('test');
       expect(
         api.components.schemas['Cat']['x-schema-extension-multiple']['test']
-      ).toEqual('test');
+      ).toEqual('test*2');
       expect(
         api.paths['/api/cats']['post']['callbacks']['myEvent'][
           '{$request.body#/callbackUrl}'

lib/decorators/api-extension.decorator.ts

@@ -1,6 +1,17 @@
+import { METHOD_METADATA } from '@nestjs/common/constants';
 import { DECORATORS } from '../constants';
-import { createMixedDecorator } from './helpers';
-import { clone } from 'lodash';
+import { clone, merge } from 'lodash';
+import { isConstructor } from '@nestjs/common/utils/shared.utils';
+
+function applyExtension(target: any, key: string, value: any): void {
+  const extensions =
+    Reflect.getMetadata(DECORATORS.API_EXTENSION, target) || {};
+  Reflect.defineMetadata(
+    DECORATORS.API_EXTENSION,
+    { [key]: value, ...extensions },
+    target
+  );
+}
 
 /**
  * @publicApi
@@ -12,9 +23,45 @@ export function ApiExtension(extensionKey: string, extensionProperties: any) {
     );
   }
 
-  const extensionObject = {
-    [extensionKey]: clone(extensionProperties)
-  };
+  return (
+    target: object | Function,
+    key?: string | symbol,
+    descriptor?: TypedPropertyDescriptor<any>
+  ): any => {
+    const extensionValue = clone(extensionProperties);
+
+    // Method-level decorator
+    if (descriptor) {
+      applyExtension(descriptor.value, extensionKey, extensionValue);
+      return descriptor;
+    }
 
-  return createMixedDecorator(DECORATORS.API_EXTENSION, extensionObject);
+    // Ensure decorator is used on a class
+    if (typeof target === 'object') {
+      return target;
+    }
+
+    // Look for API methods
+    const apiMethods = Object.getOwnPropertyNames(target.prototype)
+      .filter((propertyKey) => !isConstructor(propertyKey))
+      .map((propertyKey) =>
+        Object.getOwnPropertyDescriptor(target.prototype, propertyKey)
+      )
+      .filter((methodDescriptor) => methodDescriptor !== undefined)
+      .filter((methodDescriptor) =>
+        Reflect.hasMetadata(METHOD_METADATA, methodDescriptor.value)
+      )
+      .map((methodDescriptor) => methodDescriptor.value);
+
+    // If we found API methods, apply the extension, otherwise assume it's a DTO and apply to the class itself.
+    if (apiMethods.length > 0) {
+      apiMethods.forEach((method) =>
+        applyExtension(method, extensionKey, extensionValue)
+      );
+    } else {
+      applyExtension(target, extensionKey, extensionValue);
+    }
+
+    return target;
+  };
 }