Address code review feedback - refactor duplicated code and improve naming

Co-authored-by: nomeguy <85475922+nomeguy@users.noreply.github.com>

Author: Copilot

src/__test__/enforcer.test.ts

@@ -78,7 +78,7 @@ test('Load casbin from strings.', async () => {
     expect(await e.enforce("alice", "data1", "write")).toBe(false);
 })
 
-const respDataWithMultipleRoles = JSON.stringify({
+const rbacMultipleRolesRespData = JSON.stringify({
     m: rbacModelStr,
     p: [
         ["p", "admin", "data1", "read"],
@@ -95,7 +95,7 @@ const respDataWithMultipleRoles = JSON.stringify({
 
 test('Authorizer with multiple roles per user', async() => {
     const authorizer = new Authorizer("auto", {endpoint: "whatever"});
-    await authorizer.initEnforcer(respDataWithMultipleRoles);
+    await authorizer.initEnforcer(rbacMultipleRolesRespData);
 
     // Test alice who has both admin and editor roles
     authorizer.user = "alice";

src/__test__/server.ts

@@ -98,9 +98,7 @@ class TestServer {
         })
     }
 
-    public async start() : Promise<void> {
-        await this.casbinServ.run();
-        this.setRouter();
+    private startServer(): Promise<void> {
         return new Promise((resolve) => {
             this.listener = this.app.listen(this.port, () => {
                 console.log(`Express server is listening at http://localhost:${this.port}`);
@@ -109,15 +107,16 @@ class TestServer {
         });
     }
 
+    public async start() : Promise<void> {
+        await this.casbinServ.run();
+        this.setRouter();
+        return this.startServer();
+    }
+
     public async startWithRBAC() : Promise<void> {
         await this.casbinServ.runWithRBAC();
         this.setRouter();
-        return new Promise((resolve) => {
-            this.listener = this.app.listen(this.port, () => {
-                console.log(`Express server is listening at http://localhost:${this.port}`);
-                resolve();
-            });
-        });
+        return this.startServer();
     }
 
     public terminate() : void {