extract event match group logic and add unit test

apps/client/src/common/hooks/useEntryAction.ts

@@ -53,6 +53,7 @@ import {
 } from '../api/rundown';
 import { logAxiosError } from '../api/utils';
 import { useEditorSettings } from '../stores/editorSettings';
+import { eventDurationMatchGroupTarget } from '../utils/time';
 
 export type EventOptions = Partial<{
   // options of any new entries (event / delay / group)
@@ -473,12 +474,16 @@ function useEntryActionsForRundown(scopedRundownId: string | undefined) {
       const rundown = queryClient.getQueryData<Rundown>(resolveCurrentRundownQueryKey());
       if (!rundown) return;
       const group = rundown.entries[groupId];
-      if (!group || !isOntimeGroup(group) || group.targetDuration === null) return;
+      if (!group || !isOntimeGroup(group)) return;
       const event = rundown.entries[eventId];
       if (!event || !isOntimeEvent(event)) return;
-      const durationDiff = group.targetDuration - group.duration;
-      const newDuration = event.duration + durationDiff;
-      if (newDuration < 0) return;
+
+      const newDuration = eventDurationMatchGroupTarget({
+        targetDuration: group.targetDuration,
+        groupDuration: group.duration,
+        eventDuration: event.duration,
+      });
+      if (!newDuration) return;
       updateTimer(eventId, 'duration', String(newDuration / MILLIS_PER_SECOND) + 's', false);
     },
     [queryClient, updateTimer, resolveCurrentRundownQueryKey],

apps/client/src/common/utils/__tests__/time.test.ts

@@ -1,6 +1,6 @@
 import { MILLIS_PER_HOUR, MILLIS_PER_MINUTE, MILLIS_PER_SECOND } from 'ontime-utils';
 
-import { formatDuration, formatTime, nowInMillis } from '../time';
+import { formatDuration, formatTime, nowInMillis, eventDurationMatchGroupTarget } from '../time';
 
 describe('nowInMillis()', () => {
   afterEach(() => {
@@ -45,6 +45,101 @@ describe('formatTime()', () => {
   });
 });
 
+describe('eventDurationMatchGroupTarget()', () => {
+  it('returns unchanged duration when group already matches target', () => {
+    const result = eventDurationMatchGroupTarget({
+      targetDuration: MILLIS_PER_HOUR,
+      groupDuration: MILLIS_PER_HOUR,
+      eventDuration: MILLIS_PER_MINUTE * 30,
+    });
+    expect(result).toStrictEqual(null);
+  });
+
+  it('increases event duration when group is shorter than target', () => {
+    // Group is 1h short of target, so event duration increases by 1h
+    const result = eventDurationMatchGroupTarget({
+      targetDuration: MILLIS_PER_HOUR * 2, // 2h
+      groupDuration: MILLIS_PER_HOUR, // 1h
+      eventDuration: MILLIS_PER_MINUTE * 30, // 30m
+    });
+    expect(result).toStrictEqual(MILLIS_PER_HOUR + MILLIS_PER_MINUTE * 30); // 1h30m
+  });
+
+  it('decreases event duration when group is longer than target', () => {
+    // Group is 30m over target, so event duration decreases by 30m
+    const result = eventDurationMatchGroupTarget({
+      targetDuration: MILLIS_PER_HOUR, // 1h
+      groupDuration: MILLIS_PER_HOUR + MILLIS_PER_MINUTE * 30, // 1h30m
+      eventDuration: MILLIS_PER_MINUTE * 30, // 30m
+    });
+    expect(result).toStrictEqual(0);
+  });
+
+  it('handles zero target duration', () => {
+    const result = eventDurationMatchGroupTarget({
+      targetDuration: 0,
+      groupDuration: MILLIS_PER_HOUR,
+      eventDuration: MILLIS_PER_HOUR,
+    });
+    expect(result).toStrictEqual(0);
+  });
+
+  it('handles zero group duration', () => {
+    const result = eventDurationMatchGroupTarget({
+      targetDuration: MILLIS_PER_HOUR,
+      groupDuration: 0,
+      eventDuration: MILLIS_PER_MINUTE * 30,
+    });
+    expect(result).toStrictEqual(MILLIS_PER_HOUR + MILLIS_PER_MINUTE * 30);
+  });
+
+  it('handles zero event duration', () => {
+    const result = eventDurationMatchGroupTarget({
+      targetDuration: MILLIS_PER_HOUR,
+      groupDuration: MILLIS_PER_MINUTE * 30,
+      eventDuration: 0,
+    });
+    expect(result).toStrictEqual(MILLIS_PER_HOUR - MILLIS_PER_MINUTE * 30);
+  });
+
+  it('handles all zero values', () => {
+    const result = eventDurationMatchGroupTarget({
+      targetDuration: 0,
+      groupDuration: 0,
+      eventDuration: 0,
+    });
+    expect(result).toStrictEqual(null);
+  });
+
+  it('returns null when result would be negative', () => {
+    // Group exceeds target by 1.5h, event shrinks by 1.5h (exceeds event duration)
+    const result = eventDurationMatchGroupTarget({
+      targetDuration: MILLIS_PER_MINUTE * 30,
+      groupDuration: MILLIS_PER_HOUR * 2,
+      eventDuration: MILLIS_PER_HOUR,
+    });
+    expect(result).toStrictEqual(null);
+  });
+
+  it('handles large durations', () => {
+    const result = eventDurationMatchGroupTarget({
+      targetDuration: MILLIS_PER_HOUR * 24, // 24h
+      groupDuration: MILLIS_PER_HOUR * 12, // 12h
+      eventDuration: MILLIS_PER_HOUR, // 1h
+    });
+    expect(result).toStrictEqual(MILLIS_PER_HOUR * 13); // 13h
+  });
+
+  it('returns null when targetDuration is null', () => {
+    const result = eventDurationMatchGroupTarget({
+      targetDuration: null,
+      groupDuration: MILLIS_PER_HOUR,
+      eventDuration: MILLIS_PER_MINUTE * 30,
+    });
+    expect(result).toStrictEqual(null);
+  });
+});
+
 describe('formatDuration()', () => {
   it('formats durations correctly', () => {
     expect(formatDuration(0)).toBe('0m');

apps/client/src/common/utils/time.ts

@@ -1,4 +1,4 @@
-import { MaybeNumber, MaybeString, OntimeEvent, Settings, TimeFormat } from 'ontime-types';
+import { Maybe, MaybeNumber, MaybeString, OntimeEvent, Settings, TimeFormat } from 'ontime-types';
 import {
   MILLIS_PER_HOUR,
   MILLIS_PER_MINUTE,
@@ -192,3 +192,29 @@ export function getExpectedTimesFromExtendedEvent(
     plannedEnd,
   };
 }
+
+/**
+ * Adjusts an event's duration so the group matches a target duration.
+ * The difference between the target and the current group duration is
+ * added to (or subtracted from) the event's duration.
+ * @param targetDuration - The desired total duration for the group, or null
+ * @param groupDuration - The current total duration of all events in the group
+ * @param eventDuration - The current duration of the event being adjusted
+ * @returns The adjusted event duration, or null if targetDuration is null or
+ *          the result would be negative
+ */
+export function eventDurationMatchGroupTarget({
+  targetDuration,
+  groupDuration,
+  eventDuration,
+}: {
+  targetDuration: Maybe<number>;
+  groupDuration: number;
+  eventDuration: number;
+}): Maybe<number> {
+  if (targetDuration === null) return null;
+  if (targetDuration === groupDuration) return null;
+  const durationDiff = targetDuration - groupDuration;
+  const newDuration = eventDuration + durationDiff;
+  return newDuration < 0 ? null : newDuration;
+}