refactor: unify logic

packages/utils/src/date-utils/checkIsNextDay.test.ts

@@ -0,0 +1,60 @@
+import { checkIsNextDay } from './checkIsNextDay';
+import { MILLIS_PER_HOUR } from './conversionUtils';
+
+describe('checkIsNextDay', () => {
+  it('returns false if the previous event duration is 0', () => {
+    const previousStart = 0;
+    const previousDuration = 0;
+    const timeStart = 0;
+    expect(checkIsNextDay(previousStart, timeStart, previousDuration)).toBeFalsy();
+  });
+
+  it('returns false if event starts after one before', () => {
+    const previousStart = 10;
+    const previousDuration = 2;
+    const timeStart = 11;
+    expect(checkIsNextDay(previousStart, timeStart, previousDuration)).toBeFalsy();
+  });
+
+  it('returns true if event starts after one before', () => {
+    const previousStart = 10;
+    const previousDuration = 2;
+    const timeStart = 9;
+    expect(checkIsNextDay(previousStart, timeStart, previousDuration)).toBeTruthy();
+  });
+
+  it('returns true if event starts at the same time as one before', () => {
+    const previousStart = 10;
+    const previousDuration = 2;
+    const timeStart = 10;
+    expect(checkIsNextDay(previousStart, timeStart, previousDuration)).toBeTruthy();
+  });
+
+  it('should account for an event that crossed midnight', () => {
+    const previousStart = 20 * MILLIS_PER_HOUR;
+    const previousDuration = 6 * MILLIS_PER_HOUR; // event finished at 02:00:00
+    const timeStart = 1 * MILLIS_PER_HOUR;
+    expect(checkIsNextDay(previousStart, timeStart, previousDuration)).toBeFalsy();
+  });
+
+  it('should account for an event that crossed midnight and there is a gap', () => {
+    const previousStart = 23 * MILLIS_PER_HOUR;
+    const timeStart = 2 * MILLIS_PER_HOUR;
+    const previousDuration = 2 * MILLIS_PER_HOUR;
+    expect(checkIsNextDay(previousStart, timeStart, previousDuration)).toBeFalsy();
+  });
+
+  it('should account for an event that crossed midnight with no overlaps', () => {
+    const previousStart = 20 * MILLIS_PER_HOUR;
+    const previousDuration = 6 * MILLIS_PER_HOUR; // event finished at 02:00:00
+    const timeStart = 19 * MILLIS_PER_HOUR;
+    expect(checkIsNextDay(previousStart, timeStart, previousDuration)).toBeFalsy();
+  });
+
+  it('should account for an event that finishes exactly at midnight', () => {
+    const previousStart = 23 * MILLIS_PER_HOUR;
+    const previousDuration = 1 * MILLIS_PER_HOUR;
+    const timeStart = 2 * MILLIS_PER_HOUR;
+    expect(checkIsNextDay(previousStart, timeStart, previousDuration)).toBeTruthy();
+  });
+});

packages/utils/src/date-utils/checkIsNextDay.ts

@@ -1,13 +1,40 @@
+import { dayInMs } from './conversionUtils.js';
+
 /**
  * Utility function checks whether a given event is the day after from its predecessor
  * We consider an event to be the day after, if it begins before the start of the previous
  * @example day after
  * 09:00 - 10:00
  * 08:00 - 10:30
+ * @example day after
+ * 23:00 - 00:00
+ * 02:00 - 03:00
  * @example same day
  * 09:00 - 10:00
  * 09:30 - 10:30
+ * @example same day, but previous crosses midnight
+ * 23:00 - 01:00
+ * 02:00 - 03:00
+ * @example same day, but previous crosses midnight (with overlap)
+ * 22:00 - 02:00
+ * 01:00 - 03:00
  */
 export function checkIsNextDay(previousStart: number, timeStart: number, previousDuration: number): boolean {
-  return previousDuration === 0 ? false : timeStart <= previousStart;
+  if (previousDuration === 0) {
+    return false;
+  }
+
+  if (timeStart <= previousStart) {
+    const normalisedPreviousEnd = previousStart + previousDuration;
+    if (normalisedPreviousEnd === dayInMs) {
+      return true;
+    }
+    // handle exception for an event that finishes exactly at midnight
+    if (normalisedPreviousEnd > dayInMs) {
+      return false;
+    }
+    return true;
+  }
+
+  return false;
 }

packages/utils/src/date-utils/getTimeFromPrevious.test.ts

@@ -7,10 +7,9 @@ describe('getTimeFromPrevious', () => {
     const previousEnd = 71700000; // 19:55
     const previousDuration = 2100000; // 35 minutes
     const currentStart = 75600000; // 21:00
-    const currentEnd = 81000000; // 22:30
     const expected = 75600000 - 71700000; // current start - previousEnd
 
-    expect(getTimeFromPrevious(currentStart, currentEnd, previousStart, previousEnd, previousDuration)).toBe(expected);
+    expect(getTimeFromPrevious(currentStart, previousStart, previousEnd, previousDuration)).toBe(expected);
   });
 
   it('accounts for partially overlapping events', () => {
@@ -18,10 +17,9 @@ describe('getTimeFromPrevious', () => {
     const previousEnd = 12;
     const previousDuration = 2;
     const currentStart = 11;
-    const currentEnd = 12;
     const expected = -(previousEnd - currentStart);
 
-    expect(getTimeFromPrevious(currentStart, currentEnd, previousStart, previousEnd, previousDuration)).toBe(expected);
+    expect(getTimeFromPrevious(currentStart, previousStart, previousEnd, previousDuration)).toBe(expected);
   });
 
   it('accounts for events that are fully contained', () => {
@@ -29,10 +27,9 @@ describe('getTimeFromPrevious', () => {
     const previousEnd = 16;
     const previousDuration = 8;
     const currentStart = 10;
-    const currentEnd = 15;
     const expected = -(previousEnd - currentStart);
 
-    expect(getTimeFromPrevious(currentStart, currentEnd, previousStart, previousEnd, previousDuration)).toBe(expected);
+    expect(getTimeFromPrevious(currentStart, previousStart, previousEnd, previousDuration)).toBe(expected);
   });
 
   it('fully overlapping events are the next day', () => {
@@ -40,9 +37,28 @@ describe('getTimeFromPrevious', () => {
     const previousEnd = 12 * MILLIS_PER_HOUR;
     const previousDuration = previousEnd - previousStart;
     const currentStart = 10 * MILLIS_PER_HOUR;
-    const currentEnd = 12 * MILLIS_PER_HOUR;
     const expected = dayInMs - previousDuration;
 
-    expect(getTimeFromPrevious(currentStart, currentEnd, previousStart, previousEnd, previousDuration)).toBe(expected);
+    expect(getTimeFromPrevious(currentStart, previousStart, previousEnd, previousDuration)).toBe(expected);
+  });
+
+  it('accounts for events that are the day after', () => {
+    const previousStart = 20 * MILLIS_PER_HOUR;
+    const previousEnd = 23 * MILLIS_PER_HOUR;
+    const previousDuration = 3 * MILLIS_PER_HOUR;
+    const currentStart = 22 * MILLIS_PER_HOUR;
+    const expected = -MILLIS_PER_HOUR; // (previousEnd - currentStart);
+
+    expect(getTimeFromPrevious(currentStart, previousStart, previousEnd, previousDuration)).toBe(expected);
+  });
+
+  it('accounts for events that cross midnight', () => {
+    const previousStart = 20 * MILLIS_PER_HOUR;
+    const previousEnd = 2 * MILLIS_PER_HOUR;
+    const previousDuration = 6 * MILLIS_PER_HOUR;
+    const currentStart = 1 * MILLIS_PER_HOUR;
+    const expected = -MILLIS_PER_HOUR; // (previousEnd - currentStart);
+
+    expect(getTimeFromPrevious(currentStart, previousStart, previousEnd, previousDuration)).toBe(expected);
   });
 });

packages/utils/src/date-utils/getTimeFromPrevious.ts

@@ -7,13 +7,12 @@ import { dayInMs } from './conversionUtils.js';
  */
 export function getTimeFromPrevious(
   currentStart: number,
-  currentEnd: number,
   previousStart?: number,
   previousEnd?: number,
   previousDuration?: number,
 ): number {
   // there is no previous event
-  if (previousStart == null || previousEnd == null || previousDuration == null) {
+  if (previousStart === undefined || previousEnd === undefined || previousDuration === undefined) {
     return 0;
   }
 
@@ -35,7 +34,6 @@ export function getTimeFromPrevious(
   }
 
   // event overlaps with previous
-  // TODO: account for midnight roll
   const overlap = previousEnd - currentStart;
   if (overlap > 0) {
     // time is a negative number indicating the amount of overlap