fix: date range is now pipe has issues around boundaries

frontend/app/src/app/modules/profile/id-card.component.ts

@@ -2,7 +2,7 @@ import {ChangeDetectionStrategy, Component, ElementRef, Input} from '@angular/co
 import {SCIdCard} from '@openstapps/core';
 import {ThingTranslateModule} from '../../translation/thing-translate.module';
 import {AsyncPipe, TitleCasePipe} from '@angular/common';
-import {InRangeNowPipe, ToDateRangePipe} from '../../util/in-range.pipe';
+import {IntervalIsNowPipe, ToDateIntervalPipe} from '../../util/in-range.pipe';
 import {TranslateModule} from '@ngx-translate/core';
 import {AnimationController, ModalController} from '@ionic/angular';
 import {ScreenBrightness} from '@capacitor-community/screen-brightness';
@@ -16,7 +16,14 @@ import {iosDuration, iosEasing, mdDuration, mdEasing} from 'src/app/animation/ea
   styleUrls: ['id-card.scss'],
   changeDetection: ChangeDetectionStrategy.OnPush,
   standalone: true,
-  imports: [ThingTranslateModule, InRangeNowPipe, ToDateRangePipe, AsyncPipe, TranslateModule, TitleCasePipe],
+  imports: [
+    ThingTranslateModule,
+    IntervalIsNowPipe,
+    ToDateIntervalPipe,
+    AsyncPipe,
+    TranslateModule,
+    TitleCasePipe,
+  ],
 })
 export class IdCardComponent {
   @Input({required: true}) item: SCIdCard;

frontend/app/src/app/modules/profile/id-card.html

@@ -4,6 +4,6 @@
   draggable="false"
   (click)="presentFullscreen()"
 />
-@if (item.validity && (item.validity | toDateRange | isInRangeNow | async) === false) {
+@if (item.validity && (item.validity | rangeToDateInterval | dfnsIntervalIsNow | async) === false) {
   <div class="expired">{{ 'profile.userInfo.expired' | translate | titlecase }}</div>
 }

frontend/app/src/app/util/in-range.pipe.ts

@@ -1,7 +1,7 @@
 import {Pipe, PipeTransform} from '@angular/core';
 import {SCRange, isInRange, SCISO8601DateRange} from '@openstapps/core';
-import {merge, Observable, timer} from 'rxjs';
-import {distinctUntilChanged, map, startWith} from 'rxjs/operators';
+import {NormalizedInterval, differenceInMilliseconds, interval, isEqual} from 'date-fns';
+import {EMPTY, Observable, SchedulerLike, asyncScheduler, concat, defer, map, of, timer} from 'rxjs';
 
 @Pipe({
   name: 'isInRange',
@@ -14,28 +14,49 @@ export class InRangePipe implements PipeTransform {
   }
 }
 
+export const MIN_DATE = new Date(0);
+export const MAX_DATE = new Date(1e15);
+
 @Pipe({
-  name: 'toDateRange',
+  name: 'rangeToDateInterval',
   pure: true,
   standalone: true,
 })
-export class ToDateRangePipe implements PipeTransform {
-  transform(value: SCISO8601DateRange): SCRange<Date> {
-    return Object.fromEntries(Object.entries(value).map(([key, value]) => [key, new Date(value)]));
+export class ToDateIntervalPipe implements PipeTransform {
+  transform(value: SCISO8601DateRange): NormalizedInterval {
+    return interval(new Date(value.gte ?? value.gt ?? MIN_DATE), new Date(value.lte ?? value.lt ?? MAX_DATE));
   }
 }
 
+/**
+ * Returns an Observable that will change its value when the current date is within the given interval.
+ */
+export function isWithinIntervalObservable(
+  value: NormalizedInterval,
+  scheduler: SchedulerLike = asyncScheduler,
+): Observable<boolean> {
+  return defer(() => {
+    const now = scheduler.now();
+    const activate = differenceInMilliseconds(value.start, now);
+    const deactivate = differenceInMilliseconds(value.end, now);
+
+    return concat(
+      of(activate <= 0 && deactivate > 0),
+      activate <= 0 ? EMPTY : timer(value.start, scheduler).pipe(map(() => true)),
+      isEqual(value.end, MAX_DATE) || deactivate <= 0
+        ? EMPTY
+        : timer(value.end, scheduler).pipe(map(() => false)),
+    );
+  });
+}
+
 @Pipe({
-  name: 'isInRangeNow',
+  name: 'dfnsIntervalIsNow',
   pure: true,
   standalone: true,
 })
-export class InRangeNowPipe implements PipeTransform {
-  transform(value: SCRange<Date>): Observable<boolean> {
-    return merge(timer(value.lte || value.lt || 0), timer(value.gte || value.gt || 0)).pipe(
-      startWith(0),
-      map(() => isInRange(new Date(), value)),
-      distinctUntilChanged(),
-    );
+export class IntervalIsNowPipe implements PipeTransform {
+  transform(value: NormalizedInterval): Observable<boolean> {
+    return isWithinIntervalObservable(value);
   }
 }

frontend/app/src/app/util/in-range.spec.ts

@@ -0,0 +1,42 @@
+import {TestScheduler} from 'rxjs/testing';
+import {MAX_DATE, MIN_DATE, isWithinIntervalObservable} from './in-range.pipe';
+import {interval} from 'date-fns';
+
+/**
+ * Test macro
+ */
+function test(range: [number | undefined, number | undefined], subscribe: string, expected: string) {
+  const testScheduler = new TestScheduler((actual, expected) => {
+    expect(actual).withContext(actual.map(JSON.stringify).join('\n')).toEqual(expected);
+  });
+
+  it(`should emit "${expected}" when "${subscribe}" for range ${range[0] ?? ''}..${range[1] ?? ''}`, () => {
+    testScheduler.run(({expectObservable}) => {
+      expectObservable(
+        isWithinIntervalObservable(
+          interval(new Date(range[0] ?? MIN_DATE), new Date(range[1] ?? MAX_DATE)),
+          testScheduler,
+        ),
+        subscribe,
+      ).toBe(expected, {t: true, f: false});
+    });
+  });
+}
+
+describe('isWithinIntervalObservable', () => {
+  test([500, undefined], '1s ^', '1s (t|)');
+  test([1000, undefined], '500ms ^', '500ms f 499ms (t|)');
+
+  test([undefined, 500], '1s ^', '1s (f|)');
+  test([undefined, 1000], '500ms ^', '500ms t 499ms (f|)');
+
+  test([1000, 2000], '500ms ^', '500ms f 499ms t 999ms (f|)');
+
+  test([500, 1000], '1500ms ^', '1500ms (f|)');
+  test([500, 1000], '1s ^', '1000ms (f|)');
+  test([500, 1000], '999ms ^', '999ms t (f|)');
+  test([500, 1000], '500ms ^', '500ms t 499ms (f|)');
+  test([500, 1000], '499ms ^', '499ms f t 499ms (f|)');
+
+  test([500, 1000], '^ 750ms !', 'f 499ms t');
+});