feat: create method on client to get websocket pattern

integration/websockets/e2e/gateway.spec.ts

@@ -66,5 +66,21 @@ describe('WebSocketGateway', () => {
     );
   });
 
+  it(`should be able to get the pattern in an interceptor`, async () => {
+    app = await createNestApp(ApplicationGateway);
+    await app.listen(3000);
+
+    ws = io('http://localhost:8080');
+    ws.emit('getClient', {
+      test: 'test',
+    });
+    await new Promise<void>(resolve =>
+      ws.on('popClient', data => {
+        expect(data.path).to.be.eql('getClient');
+        resolve();
+      }),
+    );
+  });
+
   afterEach(() => app.close());
 });

integration/websockets/e2e/ws-gateway.spec.ts

@@ -194,6 +194,30 @@ describe('WebSocketGateway (WsAdapter)', () => {
     });
   });
 
+  it('should let the execution context have a getPattern() method on getClient()', async () => {
+    app = await createNestApp(ApplicationGateway);
+    await app.listen(3000);
+
+    ws = new WebSocket('ws://localhost:8080');
+    await new Promise(resolve => ws.on('open', resolve));
+
+    ws.send(
+      JSON.stringify({
+        event: 'getClient',
+        data: {
+          test: 'test',
+        },
+      }),
+    );
+    await new Promise<void>(resolve =>
+      ws.on('message', data => {
+        expect(JSON.parse(data).data.path).to.be.eql('getClient');
+        ws.close();
+        resolve();
+      }),
+    );
+  });
+
   afterEach(async function () {
     await app.close();
   });

integration/websockets/src/app.gateway.ts

@@ -1,8 +1,10 @@
+import { UseInterceptors } from '@nestjs/common';
 import {
   MessageBody,
   SubscribeMessage,
   WebSocketGateway,
 } from '@nestjs/websockets';
+import { RequestInterceptor } from './request.interceptor';
 
 @WebSocketGateway(8080)
 export class ApplicationGateway {
@@ -13,4 +15,13 @@ export class ApplicationGateway {
       data,
     };
   }
+
+  @UseInterceptors(RequestInterceptor)
+  @SubscribeMessage('getClient')
+  getPathCalled(client, data) {
+    return {
+      event: 'popClient',
+      data: { ...data, path: client.pattern },
+    };
+  }
 }

integration/websockets/src/request.interceptor.ts

@@ -0,0 +1,11 @@
+import { CallHandler, ExecutionContext, Injectable } from '@nestjs/common';
+
+@Injectable()
+export class RequestInterceptor {
+  intercept(context: ExecutionContext, next: CallHandler) {
+    const client = context.switchToWs().getClient();
+    const pattern = context.switchToWs().getPattern();
+    client.pattern = pattern;
+    return next.handle();
+  }
+}

integration/websockets/src/server.gateway.ts

@@ -1,4 +1,6 @@
+import { UseInterceptors } from '@nestjs/common';
 import { SubscribeMessage, WebSocketGateway } from '@nestjs/websockets';
+import { RequestInterceptor } from './request.interceptor';
 
 @WebSocketGateway()
 export class ServerGateway {
@@ -9,4 +11,13 @@ export class ServerGateway {
       data,
     };
   }
+
+  @UseInterceptors(RequestInterceptor)
+  @SubscribeMessage('getClient')
+  getPathCalled(client, data) {
+    return {
+      event: 'popClient',
+      data: { ...data, path: client.pattern },
+    };
+  }
 }

packages/common/interfaces/features/arguments-host.interface.ts

@@ -31,6 +31,10 @@ export interface WsArgumentsHost {
    * Returns the client object.
    */
   getClient<T = any>(): T;
+  /**
+   * Returns the pattern for the event
+   */
+  getPattern(): string;
 }
 
 /**

packages/core/helpers/execution-context-host.ts

@@ -59,6 +59,7 @@ export class ExecutionContextHost implements ExecutionContext {
     return Object.assign(this, {
       getClient: () => this.getArgByIndex(0),
       getData: () => this.getArgByIndex(1),
+      getPattern: () => this.getArgByIndex(this.getArgs().length - 1),
     });
   }
 }

packages/websockets/context/ws-context-creator.ts

@@ -23,7 +23,7 @@ import {
   InterceptorsContextCreator,
 } from '@nestjs/core/interceptors';
 import { PipesConsumer, PipesContextCreator } from '@nestjs/core/pipes';
-import { PARAM_ARGS_METADATA } from '../constants';
+import { MESSAGE_METADATA, PARAM_ARGS_METADATA } from '../constants';
 import { WsException } from '../errors/ws-exception';
 import { WsParamsFactory } from '../factories/ws-params-factory';
 import { ExceptionFiltersContext } from './exception-filters-context';
@@ -66,7 +66,6 @@ export class WsContextCreator {
       methodName,
       contextType,
     );
-
     const exceptionHandler = this.exceptionFiltersContext.create(
       instance,
       callback,
@@ -110,6 +109,8 @@ export class WsContextCreator {
     };
 
     return this.wsProxy.create(async (...args: unknown[]) => {
+      args.push(this.reflectCallbackPattern(callback));
+
       const initialArgs = this.contextUtils.createNullArray(argsLength);
       fnCanActivate && (await fnCanActivate(args));
 
@@ -131,6 +132,10 @@ export class WsContextCreator {
     return Reflect.getMetadata(PARAMTYPES_METADATA, instance, callback.name);
   }
 
+  public reflectCallbackPattern(callback: (...args: any[]) => any): string {
+    return Reflect.getMetadata(MESSAGE_METADATA, callback);
+  }
+
   public createGuardsFn<TContext extends string = ContextType>(
     guards: any[],
     instance: Controller,