various code quality fixes (#5792)

* various code quality fixes

* reduce duplicated code

* add safety check

lib/core/services/authentication.service.ts

@@ -157,7 +157,7 @@ export class AuthenticationService {
      * @returns True if set, false otherwise
      */
     isRememberMeSet(): boolean {
-        return (this.cookie.getItem(REMEMBER_ME_COOKIE_KEY) === null) ? false : true;
+        return (this.cookie.getItem(REMEMBER_ME_COOKIE_KEY) !== null);
     }
 
     /**

lib/core/services/identity-group.service.ts

@@ -287,10 +287,7 @@ export class IdentityGroupService {
     checkGroupHasClientApp(groupId: string, clientId: string): Observable<boolean> {
         return this.getClientRoles(groupId, clientId).pipe(
                     map((response: any[]) => {
-                        if (response && response.length > 0) {
-                            return true;
-                        }
-                        return false;
+                        return response && response.length > 0;
                     }),
                     catchError((error) => this.handleError(error))
             );

lib/core/services/identity-user.service.ts

@@ -201,10 +201,7 @@ export class IdentityUserService {
     checkUserHasClientApp(userId: string, clientId: string): Observable<boolean> {
         return this.getClientRoles(userId, clientId).pipe(
             map((clientRoles: any[]) => {
-                if (clientRoles.length > 0) {
-                    return true;
-                }
-                return false;
+                return clientRoles.length > 0;
             })
         );
     }

lib/core/services/upload.service.ts

@@ -82,7 +82,7 @@ export class UploadService {
      * @returns True if a file is uploading, false otherwise
      */
     isUploading(): boolean {
-        return this.activeTask ? true : false;
+        return !!this.activeTask;
     }
 
     /**