feat: add support observable for nest plugin

Author: jbl428

README.md

@@ -118,7 +118,7 @@ class UserService {
   options of the circuit breaker. You can use global options by setting the `circuitBreakerOption` property in the module.
   `options` is from [opossum](https://www.npmjs.com/package/opossum) library.
 
-- `@Observable()`: Marks the method as an observable method. If this decorator is not specified, the method will return
+- `@ObservableResponse()`: Marks the method as an observable method. If this decorator is not specified, the method will return
   a promise.
 
 ## Auto generate `@ResponseBody()` from return type of exchange method

lib/fixtures/fake-service-code.ts

@@ -1,4 +1,4 @@
-export const returnStringServiceCode = `
+export const returnStringServiceCode = /* language=typescript */ `
 import { HttpInterface, GetExchange } from '@r2don/nest-http-interface';
 
 @HttpInterface()
@@ -11,7 +11,7 @@ class TextService {
   }
 }`;
 
-export const hasResponseBodyServiceCode = `
+export const hasResponseBodyServiceCode = /* language=typescript */ `
 import { HttpInterface, PostExchange, ResponseBody } from '@r2don/nest-http-interface';
 import { User } from './user.entity';
 
@@ -24,7 +24,7 @@ class UserService {
   }
 }`;
 
-export const notPromiseServiceCode = `
+export const notPromiseServiceCode = /* language=typescript */ `
 import { HttpInterface, GetExchange, ResponseBody } from '@r2don/nest-http-interface';
 
 @HttpInterface()
@@ -35,8 +35,9 @@ class UserService {
   }
 }`;
 
-export const needResponseBodyServiceCode = `
-import { HttpInterface, GraphQLExchange } from '@r2don/nest-http-interface';
+export const needResponseBodyServiceCode = /* language=typescript */ `
+import { HttpInterface, GraphQLExchange, ObservableResponse } from '@r2don/nest-http-interface';
+import { Observable } from "rxjs";
 
 class ResponseClass {}
 
@@ -46,9 +47,15 @@ class UserService {
   async getUser(): Promise<ResponseClass> {
     throw new Error('not implemented');
   }
+
+  @GraphQLExchange()
+  @ObservableResponse()
+  getUserObservable(): Observable<ResponseClass> {
+    throw new Error('not implemented');
+  }
 }`;
 
-export const arrayResponseBodyServiceCode = `
+export const arrayResponseBodyServiceCode = /* language=typescript */ `
 import { HttpInterface, GetExchange } from '@r2don/nest-http-interface';
 
 class ResponseClass {}

lib/plugin/visitors/__snapshots__/http-interface.visitor.spec.ts.snap

@@ -46,10 +46,17 @@ let UserService = class UserService {
     async getUser() {
         throw new Error('not implemented');
     }
+    getUserObservable() {
+        throw new Error('not implemented');
+    }
 };
 __decorate([
     (0, nest_http_interface_1.GraphQLExchange)()
 ], UserService.prototype, \\"getUser\\", null);
+__decorate([
+    (0, nest_http_interface_1.GraphQLExchange)(),
+    (0, nest_http_interface_1.ObservableResponse)()
+], UserService.prototype, \\"getUserObservable\\", null);
 UserService = __decorate([
     (0, nest_http_interface_1.HttpInterface)()
 ], UserService);
@@ -76,7 +83,7 @@ UserService = __decorate([
 "
 `;
 
-exports[`HttpInterfaceVisitor > should ignore if return type if not a promise  1`] = `
+exports[`HttpInterfaceVisitor > should ignore if return type if not a promise or observable 1`] = `
 "\\"use strict\\";
 Object.defineProperty(exports, \\"__esModule\\", { value: true });
 const nest_http_interface_1 = require(\\"@r2don/nest-http-interface\\");
@@ -124,11 +131,19 @@ let UserService = class UserService {
     async getUser() {
         throw new Error('not implemented');
     }
+    getUserObservable() {
+        throw new Error('not implemented');
+    }
 };
 __decorate([
     (0, nest_http_interface_1.GraphQLExchange)(),
     r2don_http_module_1.ResponseBody(ResponseClass)
 ], UserService.prototype, \\"getUser\\", null);
+__decorate([
+    (0, nest_http_interface_1.GraphQLExchange)(),
+    (0, nest_http_interface_1.ObservableResponse)(),
+    r2don_http_module_1.ResponseBody(ResponseClass)
+], UserService.prototype, \\"getUserObservable\\", null);
 UserService = __decorate([
     (0, nest_http_interface_1.HttpInterface)()
 ], UserService);

lib/plugin/visitors/http-interface.visitor.spec.ts

@@ -69,7 +69,7 @@ describe('HttpInterfaceVisitor', () => {
     expect(result.outputText).toMatchSnapshot();
   });
 
-  test('should ignore if return type if not a promise ', () => {
+  test('should ignore if return type if not a promise or observable', () => {
     // given
     const filename = 'text.service.ts';
     const fakeProgram = ts.createProgram([filename], compilerOptions);

lib/plugin/visitors/http-interface.visitor.ts

@@ -180,7 +180,8 @@ export class HttpInterfaceVisitor {
       node.type == null ||
       !ts.isTypeReferenceNode(node.type) ||
       !ts.isIdentifier(node.type.typeName) ||
-      node.type.typeName.text !== 'Promise'
+      (node.type.typeName.text !== 'Promise' &&
+        node.type.typeName.text !== 'Observable')
     ) {
       return undefined;
     }