refactor: socket.once을 최대한 사용하도록 리팩토링, 삼항연산자 사용

- socket.on후 socket.off로 이벤트의 리스너를 지우는 방식을 socket.once로 이벤트 발생시 바로 한번만 호출되고 리스너가 없어지도록 변경
- 삼항연산자를 사용해 더 짧고 가독성있게 변경

backend/src/project/service/project.service.ts

@@ -89,7 +89,6 @@ export class ProjectService {
 
   async deleteLink(project: Project, linkId: number) {
     const result = await this.projectRepository.deleteLink(project, linkId);
-    if (result) return true;
-    else return false;
+    return result ? true : false;
   }
 }

backend/test/project/ws-link.e2e-spec.ts

@@ -74,15 +74,14 @@ describe('WS link', () => {
 
     const expectCreateLink = (socket, url, description) => {
       return new Promise<void>((resolve, reject) => {
-        socket.on('landing', async (data) => {
+        socket.once('landing', async (data) => {
           const { content, action, domain } = data;
           expect(domain).toBe('link');
           expect(action).toBe('create');
           expect(content?.description).toBe(description);
           expect(content?.id).toBeDefined();
           expect(content?.url).toBe(url);
           expect(content?.description).toBe(description);
-          socket.off('landing');
           resolve(content.id);
         });
       });
@@ -170,11 +169,10 @@ describe('WS link', () => {
     });
     const getCreateLinkMsg = (socket) => {
       return new Promise<void>((res) => {
-        socket.on('landing', (data) => {
+        socket.once('landing', (data) => {
           const { action, domain } = data;
           expect(domain).toBe('link');
           expect(action).toBe('create');
-          socket.off('landing');
           res();
         });
       });
@@ -241,28 +239,26 @@ describe('WS link', () => {
     });
     const expectCreateLinkAndReturnFirstLinkId = (socket, url, description) => {
       return new Promise<void>((resolve, reject) => {
-        socket.on('landing', async (data) => {
+        socket.once('landing', async (data) => {
           const { content, action, domain } = data;
           expect(domain).toBe('link');
           expect(action).toBe('create');
           expect(content?.description).toBe(description);
           expect(content?.id).toBeDefined();
           expect(content?.url).toBe(url);
           expect(content?.description).toBe(description);
-          socket.off('landing');
           resolve(content.id);
         });
       });
     };
 
     const expectDeleteLink = (socket, linkId) => {
       return new Promise<void>((resolve, reject) => {
-        socket.on('landing', async (data) => {
+        socket.once('landing', async (data) => {
           const { content, action, domain } = data;
           expect(domain).toBe('link');
           expect(action).toBe('delete');
           expect(content?.id).toBe(linkId);
-          socket.off('landing');
           resolve();
         });
       });

backend/test/project/ws-project-landing-page.e2e-spec.ts

@@ -178,11 +178,10 @@ describe('WS landing', () => {
 
 const getCreateMemoMsg = (socket) => {
   return new Promise<void>((res) => {
-    socket.on('landing', (data) => {
+    socket.once('landing', (data) => {
       const { action, domain } = data;
       expect(domain).toBe('memo');
       expect(action).toBe('create');
-      socket.off('landing');
       res();
     });
   });