Add Regex to check if user is searching for all subjects or if subjects is blank.

src/app/degree-planner/course-search/course-search.component.ts

@@ -131,8 +131,8 @@ export class CourseSearchComponent implements OnInit, OnDestroy {
     (this.courseSearchForm.get(
       'subject',
     ) as AbstractControl).valueChanges.subscribe(value => {
-      // If the subject value is blank, reset the filtered subjects
-      if (value === '') {
+      // If the subject value is blank, or if the user is typing "all"
+      if (new RegExp('^([Aa]?[Ll]{0,2})$').test(value.trim())) {
         this.filteredSubjects = this.subjects;
         return;
       }