feat: email client prototype

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

@@ -1,6 +1,6 @@
 import {Pipe, PipeTransform} from '@angular/core';
 import {SCRange, isInRange, SCISO8601DateRange} from '@openstapps/core';
-import {NormalizedInterval, differenceInMilliseconds, interval} from 'date-fns';
+import {NormalizedInterval, differenceInMilliseconds, interval, isEqual} from 'date-fns';
 import {EMPTY, Observable, SchedulerLike, asyncScheduler, concat, defer, map, of, timer} from 'rxjs';
 
 @Pipe({
@@ -16,8 +16,6 @@ export class InRangePipe implements PipeTransform {
 
 export const MIN_DATE = new Date(0);
 export const MAX_DATE = new Date(1e15);
-// Maximum safe delay for JavaScript timers (~24.8 days)
-export const MAX_DELAY = 2 ** 31 - 1;
 
 @Pipe({
   name: 'rangeToDateInterval',
@@ -45,7 +43,7 @@ export function isWithinIntervalObservable(
     return concat(
       of(activate <= 0 && deactivate > 0),
       activate <= 0 ? EMPTY : timer(value.start, scheduler).pipe(map(() => true)),
-      differenceInMilliseconds(value.end, now) >= MAX_DELAY || deactivate <= 0
+      isEqual(value.end, MAX_DATE) || deactivate <= 0
         ? EMPTY
         : timer(value.end, scheduler).pipe(map(() => false)),
     );

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

@@ -1,7 +1,6 @@
 import {TestScheduler} from 'rxjs/testing';
 import {MAX_DATE, MIN_DATE, isWithinIntervalObservable} from './in-range.pipe';
 import {interval} from 'date-fns';
-import {MAX_DELAY} from './in-range.pipe';
 
 /**
  * Test macro
@@ -40,7 +39,4 @@ describe('isWithinIntervalObservable', () => {
   test([500, 1000], '499ms ^', '499ms f t 499ms (f|)');
 
   test([500, 1000], '^ 750ms !', 'f 499ms t');
-
-  // Long interval test case: emit `true` and then complete (EMPTY) because `end` is beyond the delay limit
-  test([500, 500 + MAX_DELAY + 2000], '1s ^', '1s (t|)');
 });