website: timetables: Fix deserialization of TA courses in share link (#4214)

Currently, the `deserializeTa` function does not correctly parse share
links with multiple TA-ed courses.

Fix it and add some unit tests for the function.

Fixes #4171

Author: zwliew

website/src/utils/timetables.test.ts

@@ -33,6 +33,7 @@ import {
   areOtherClassesAvailable,
   arrangeLessonsForWeek,
   arrangeLessonsWithinDay,
+  deserializeTa,
   deserializeTimetable,
   doLessonsOverlap,
   findExamClashes,
@@ -678,3 +679,17 @@ describe(getEndTimeAsDate, () => {
     expect(getEndTimeAsDate(lesson, date)).toEqual(new Date(2018, 5, 10, 10, 45));
   });
 });
+
+describe(deserializeTa, () => {
+  test('should deserialize TA modules string into object', () => {
+    expect(deserializeTa('?')).toEqual({});
+    expect(deserializeTa('?CS1010S=REC:1,TUT:8')).toEqual({});
+    expect(deserializeTa('?CS1010S=REC:1,TUT:8&ta=CS3210(TUT:02)')).toEqual({
+      CS3210: [['Tutorial', '02']],
+    });
+    expect(deserializeTa('?CS1010S=REC:1,TUT:8&ta=CS3210(TUT:02),CS3219(TUT:15)')).toEqual({
+      CS3210: [['Tutorial', '02']],
+      CS3219: [['Tutorial', '15']],
+    });
+  });
+});

website/src/utils/timetables.ts

@@ -625,7 +625,7 @@ export function deserializeTa(serialized: string): TaModulesConfig {
   // If user manually enters multiple TA query keys, use latest one
   const ta = Array.isArray(params.ta) ? last(params.ta) : params.ta;
   if (!ta) return deserialized;
-  ta.split(`)${LESSON_SEP}`).forEach((moduleConfig) => {
+  ta.split(LESSON_SEP).forEach((moduleConfig) => {
     const moduleCodeMatches = moduleConfig.match(/(.*)\(/);
     if (moduleCodeMatches === null) {
       return;