From 3c2418f9a76611e18b2cf0909be1e13785e1d4d5 Mon Sep 17 00:00:00 2001
From: Ryan Yeo <99546476+kaze-droid@users.noreply.github.com>
Date: Mon, 25 Nov 2024 23:55:34 +0800
Subject: [PATCH] nusmoderator: Include preceding weekend in specific week
 types (#3870)

* modify calculation of week type

* move tests into group, add false positive test

* adjust comments

---------

Co-authored-by: Kok Rui Wong <kokruiwong@gmail.com>
---
 .../nusmoderator/src/academicCalendar.test.ts | 45 +++++++++++++++++++
 packages/nusmoderator/src/academicCalendar.ts | 28 ++++++++++++
 2 files changed, 73 insertions(+)

diff --git a/packages/nusmoderator/src/academicCalendar.test.ts b/packages/nusmoderator/src/academicCalendar.test.ts
index 9d58af0c24..f22c89e255 100644
--- a/packages/nusmoderator/src/academicCalendar.test.ts
+++ b/packages/nusmoderator/src/academicCalendar.test.ts
@@ -247,6 +247,51 @@ describe('getAcadWeekInfo', () => {
       type: 'Orientation',
       num: null,
     });
+    expect(getAcadWeekInfo(new Date('September 8, 2024'))).toEqual({
+      year: '24/25',
+      sem: 'Semester 1',
+      type: 'Instructional',
+      num: 4,
+    });
+  });
+
+  it('correctly handles week types whose days include the preceding weekend', () => {
+    expect(getAcadWeekInfo(new Date('September 21, 2024'))).toEqual({
+      year: '24/25',
+      sem: 'Semester 1',
+      type: 'Recess',
+      num: null,
+    });
+    expect(getAcadWeekInfo(new Date('November 16, 2024'))).toEqual({
+      year: '24/25',
+      sem: 'Semester 1',
+      type: 'Reading',
+      num: null,
+    });
+    expect(getAcadWeekInfo(new Date('November 23, 2024'))).toEqual({
+      year: '24/25',
+      sem: 'Semester 1',
+      type: 'Examination',
+      num: 1,
+    });
+    expect(getAcadWeekInfo(new Date('February 25, 2025'))).toEqual({
+      year: '24/25',
+      sem: 'Semester 2',
+      type: 'Recess',
+      num: null,
+    });
+    expect(getAcadWeekInfo(new Date('April 19, 2025'))).toEqual({
+      year: '24/25',
+      sem: 'Semester 2',
+      type: 'Reading',
+      num: null,
+    });
+    expect(getAcadWeekInfo(new Date('April 27, 2025'))).toEqual({
+      year: '24/25',
+      sem: 'Semester 2',
+      type: 'Examination',
+      num: 1,
+    });
   });
 });
 
diff --git a/packages/nusmoderator/src/academicCalendar.ts b/packages/nusmoderator/src/academicCalendar.ts
index ef77a27195..e3f5fbbd37 100644
--- a/packages/nusmoderator/src/academicCalendar.ts
+++ b/packages/nusmoderator/src/academicCalendar.ts
@@ -142,14 +142,22 @@ export function getAcadWeekInfo(date: Date): AcadWeekInfo {
   const acadYear = currentAcad.year;
   const acadYearStartDate = getAcadYearStartDate(acadYear);
 
+  // Computes week number of the academic year, assuming that each week
+  // starts on Monday and ends on Sunday.
   let acadWeekNumber = Math.ceil(
     (date.getTime() - acadYearStartDate.getTime() + 1) / oneWeekDuration,
   );
+
   // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
   const semester = getAcadSem(acadWeekNumber)!;
 
+  // Check if it is weekend
+  const dayOfWeek = date.getDay();
+  const isWeekend = dayOfWeek === 0 || dayOfWeek === 6;
+
   let weekType = null;
   let weekNumber = null;
+
   switch (semester) {
     case sem2: // Semester 2 starts 22 weeks after Week 1 of semester 1
       acadWeekNumber -= 22;
@@ -164,6 +172,26 @@ export function getAcadWeekInfo(date: Date): AcadWeekInfo {
         break;
       }
       acadWeekNumber -= 1;
+
+      // Handle special cases where some week types include the week's preceding weekend
+      if (isWeekend) {
+        if (acadWeekNumber === 6) {
+          weekType = 'Recess';
+          weekNumber = null;
+          break;
+        }
+        if (acadWeekNumber === 14) {
+          weekType = 'Reading';
+          weekNumber = null;
+          break;
+        }
+        if (acadWeekNumber === 15) {
+          weekType = 'Examination';
+          weekNumber = 1;
+          break;
+        }
+      }
+
       // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
       const acadWeek = getAcadWeekName(acadWeekNumber)!;
       weekType = acadWeek.weekType;