fix: conversations hidden when filtering by a date range (#15385)

app/javascript/dashboard/store/modules/conversations/helpers/filterHelpers.js

@@ -170,6 +170,35 @@ const contains = (filterValue, conversationValue) => {
   return false;
 };
 
+const DATE_ONLY_PATTERN = /^\d{4}-\d{2}-\d{2}$/;
+
+/**
+ * Checks whether a value is a calendar date without a time, as emitted by the
+ * date pickers and required by the backend (Date.iso8601)
+ * @param {*} value - The value to check
+ * @returns {Boolean} - Returns true for `YYYY-MM-DD` strings
+ */
+const isDateOnly = value =>
+  typeof value === 'string' && DATE_ONLY_PATTERN.test(value);
+
+/**
+ * Reduces a value to the UTC calendar day it falls on
+ * @param {*} value - An epoch timestamp, an ISO string or a `YYYY-MM-DD` string
+ * @returns {Number|null} - Milliseconds at UTC midnight, or null when unparseable
+ *
+ * `coerceToDate` reads a `YYYY-MM-DD` string as midnight in the browser
+ * timezone, which lands on the previous day for browsers behind UTC.
+ */
+const toUtcDay = value => {
+  const date = isDateOnly(value)
+    ? new Date(`${value}T00:00:00.000Z`)
+    : coerceToDate(value);
+
+  if (date === null) return null;
+
+  return Date.UTC(date.getUTCFullYear(), date.getUTCMonth(), date.getUTCDate());
+};
+
 /**
  * Compares two date values using a comparison function
  * @param {*} conversationValue - The conversation value to compare
@@ -178,13 +207,24 @@ const contains = (filterValue, conversationValue) => {
  * @returns {Boolean} - Returns true if the comparison succeeds, false otherwise
  */
 const compareDates = (conversationValue, filterValue, compareFn) => {
-  const conversationDate = coerceToDate(conversationValue);
-
   // In saved views, the filterValue might be returned as an Array
   // In conversation list, when filtering, the filterValue will be returned as a string
   const valueToCompare = Array.isArray(filterValue)
     ? filterValue[0]
     : filterValue;
+
+  // A date filter compares whole days. The backend casts both sides with
+  // `::date` (Filters::FilterHelper#date_filter), so the time of day never
+  // takes part and the day is the one in UTC.
+  if (isDateOnly(valueToCompare)) {
+    const conversationDay = toUtcDay(conversationValue);
+    const filterDay = toUtcDay(valueToCompare);
+
+    if (conversationDay === null || filterDay === null) return false;
+    return compareFn(conversationDay, filterDay);
+  }
+
+  const conversationDate = coerceToDate(conversationValue);
   const filterDate = coerceToDate(valueToCompare);
 
   if (conversationDate === null || filterDate === null) return false;

app/javascript/dashboard/store/modules/conversations/helpers/specs/filterHelpers.spec.js

@@ -1,4 +1,4 @@
-import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
 import { matchesFilters } from '../filterHelpers';
 
 // SAMPLE PAYLOAD
@@ -1798,4 +1798,87 @@ describe('filterHelpers', () => {
       expect(matchesFilters(conversation, filters)).toBe(false);
     });
   });
+
+  // These expectations hold in every timezone. Run the suite under
+  // TZ=Asia/Kolkata and TZ=America/Los_Angeles to cover browsers ahead of and
+  // behind UTC, where the boundary used to shift and hide rows.
+  describe('date-only filter values are compared as whole UTC days', () => {
+    const buildFilter = (filterOperator, value) => [
+      {
+        attribute_key: 'last_activity_at',
+        filter_operator: filterOperator,
+        values: [value],
+        query_operator: 'and',
+      },
+    ];
+
+    const lateInDay = { last_activity_at: 1786132800 }; // 2026-08-07 20:00 UTC
+    const earlyInDay = { last_activity_at: 1786075200 }; // 2026-08-07 04:00 UTC
+
+    it('includes both ends of the day for is_less_than', () => {
+      expect(
+        matchesFilters(lateInDay, buildFilter('is_less_than', '2026-08-08'))
+      ).toBe(true);
+      expect(
+        matchesFilters(earlyInDay, buildFilter('is_less_than', '2026-08-08'))
+      ).toBe(true);
+    });
+
+    it('includes both ends of the day for is_greater_than', () => {
+      expect(
+        matchesFilters(lateInDay, buildFilter('is_greater_than', '2026-08-06'))
+      ).toBe(true);
+      expect(
+        matchesFilters(earlyInDay, buildFilter('is_greater_than', '2026-08-06'))
+      ).toBe(true);
+    });
+
+    it('excludes the whole day named by the bound', () => {
+      expect(
+        matchesFilters(lateInDay, buildFilter('is_greater_than', '2026-08-07'))
+      ).toBe(false);
+      expect(
+        matchesFilters(earlyInDay, buildFilter('is_greater_than', '2026-08-07'))
+      ).toBe(false);
+      expect(
+        matchesFilters(lateInDay, buildFilter('is_less_than', '2026-08-07'))
+      ).toBe(false);
+      expect(
+        matchesFilters(earlyInDay, buildFilter('is_less_than', '2026-08-07'))
+      ).toBe(false);
+    });
+
+    it('still excludes conversations outside the range', () => {
+      expect(
+        matchesFilters(lateInDay, buildFilter('is_less_than', '2026-08-06'))
+      ).toBe(false);
+      expect(
+        matchesFilters(earlyInDay, buildFilter('is_greater_than', '2026-08-08'))
+      ).toBe(false);
+    });
+
+    // Date custom attributes are stored as full ISO strings, not date-only ones
+    it('compares date custom attributes against the same boundary', () => {
+      const filters = [
+        {
+          attribute_key: 'renewal_date',
+          filter_operator: 'is_greater_than',
+          values: ['2026-08-07'],
+          query_operator: 'and',
+        },
+      ];
+      expect(
+        matchesFilters(
+          { custom_attributes: { renewal_date: '2026-08-08T00:00:00.000Z' } },
+          filters
+        )
+      ).toBe(true);
+      expect(
+        matchesFilters(
+          { custom_attributes: { renewal_date: '2026-08-07T00:00:00.000Z' } },
+          filters
+        )
+      ).toBe(false);
+    });
+  });
 });