[#12697] Create generic builder (#12698)

* create generic builder

src/web/app/pages-instructor/instructor-course-edit-page/instructor-course-edit-page.component.spec.ts

@@ -20,6 +20,7 @@ import { ViewRolePrivilegesModalComponent } from './view-role-privileges-modal/v
 import { CourseService } from '../../../services/course.service';
 import { InstructorService } from '../../../services/instructor.service';
 import { SimpleModalService } from '../../../services/simple-modal.service';
+import { instructorBuilder } from '../../../test-helpers/generic-builder';
 import { createMockNgbModalRef } from '../../../test-helpers/mock-ngb-modal-ref';
 import { Course, Instructor, InstructorPermissionRole, JoinState } from '../../../types/api-output';
 import { InstructorCreateRequest } from '../../../types/api-request';
@@ -41,26 +42,19 @@ const testCourse: Course = {
   deletionTimestamp: 1000,
 };
 
-const testInstructor1: Instructor = {
-  courseId: 'exampleId',
-  email: '[email protected]',
-  joinState: JoinState.JOINED,
-  name: 'Instructor 1',
-};
+const testInstructor1: Instructor = instructorBuilder.email('[email protected]').name('Instructor 1').build();
 
-const testInstructor2: Instructor = {
-  courseId: 'exampleId',
-  email: '[email protected]',
-  joinState: JoinState.NOT_JOINED,
-  name: 'Instructor 2',
-};
+const testInstructor2 = instructorBuilder
+  .email('[email protected]')
+  .joinState(JoinState.NOT_JOINED)
+  .name('Instructor 2')
+  .build();
 
-const testInstructor3: Instructor = {
-  courseId: 'exampleId',
-  email: '[email protected]',
-  joinState: JoinState.NOT_JOINED,
-  name: 'Instructor 3',
-};
+const testInstructor3 = instructorBuilder
+  .email('[email protected]')
+  .joinState(JoinState.NOT_JOINED)
+  .name('Instructor 3')
+  .build();
 
 const emptyInstructorPanel: InstructorEditPanel = {
   googleId: '',

src/web/test-helpers/generic-builder.ts

@@ -0,0 +1,61 @@
+import { Course, Instructor, JoinState } from '../types/api-output';
+
+type GenericBuilder<T> = {
+  [K in keyof T]: (value: T[K]) => GenericBuilder<T>;
+} & { build(): T };
+
+/**
+ * A generic builder function that creates a builder object for constructing objects with specified initial values.
+ *
+ * @template T - The type of object being constructed.
+ * @param initialValues - The initial values for the object being constructed.
+ * @returns A generic builder object.
+ * @example
+ * // Create a course builder with initial values.
+ * const courseBuilder = createBuilder<Course>({
+ *   courseId: 'exampleId',
+ *   courseName: '',
+ *   timeZone: '',
+ *   institute: '',
+ *   creationTimestamp: 0,
+ *   deletionTimestamp: 0,
+ * });
+ *
+ * // Usage of builder:
+ * const myCourse = courseBuilder
+ *   .courseName('Introduction to TypeScript')
+ *   .timeZone('UTC+0')
+ *   .institute('My University')
+ *   .creationTimestamp(Date.now())
+ *   .build();
+ */
+export function createBuilder<T extends object>(initialValues: T): GenericBuilder<T> {
+  const builder: any = {};
+
+  (Object.keys(initialValues) as (keyof T)[]).forEach((key) => {
+    builder[key] = (value: T[keyof T]) => {
+      initialValues[key] = value;
+      return builder;
+    };
+  });
+
+  builder.build = () => ({ ...initialValues });
+
+  return builder;
+}
+
+export const courseBuilder = createBuilder<Course>({
+  courseId: 'exampleId',
+  courseName: '',
+  timeZone: '',
+  institute: '',
+  creationTimestamp: 0,
+  deletionTimestamp: 0,
+});
+
+export const instructorBuilder = createBuilder<Instructor>({
+  courseId: 'exampleId',
+  email: '',
+  name: '',
+  joinState: JoinState.JOINED,
+});