fix: pass ticket_brand_id in LURF autocomplete request

When a lookup relationship field has a brand filter condition
(ticket_brand_id), the autocomplete API request now includes the
brand ID from the current Help Center brand. Previously the filter
was sent with an empty value because brandId was not wired through
to the LookupField component.

- Add brandId prop to LookupField
- Pass brandId from RequestFormField to LookupField
- Add startsWith("ticket_fields_") guard to skip non-field filters
- Add ticket_brand_id to search params when brand filter is defined
- Add tests for ticket_brand_id filter handling

CRYSTAL-888

Author: zendesk-navkumar

assets/ticket-fields-bundle.js

@@ -143,6 +143,7 @@ export const RequestFormField = ({
               ? (organizationField?.value as string)
               : defaultOrganizationId
           }
+          brandId={brandId}
           visibleFields={visibleFields}
           onChange={(value) => handleChange(field, value)}
           buildLookupFieldOptions={buildLookupFieldOptions}

src/modules/ticket-fields/RequestFormField.tsx

@@ -141,6 +141,74 @@ describe("buildAdvancedDynamicFilterParams", () => {
     expect(result).toEqual([]);
   });
 
+  it("returns ticket_brand_id filter with null value when no matching field exists", () => {
+    const filter: LookupRelationshipFieldFilter = {
+      all: [
+        {
+          field: "custom_object.testco.custom_fields.brandlurf",
+          operator: "matches",
+          value: "ticket_brand_id",
+        },
+      ],
+      any: [],
+    };
+    const fields: TicketFieldObject[] = [
+      {
+        id: 12345,
+        name: "Test Field 1",
+        value: "fooValue",
+        error: null,
+        label: "Test Field 1",
+        required: false,
+        description: "",
+        type: "text",
+        options: [],
+      },
+    ];
+
+    const result = buildAdvancedDynamicFilterParams(filter, fields);
+
+    expect(result).toEqual([{ key: "ticket_brand_id", value: null }]);
+  });
+
+  it("returns ticket_brand_id alongside ticket_fields filters", () => {
+    const filter: LookupRelationshipFieldFilter = {
+      all: [
+        {
+          field: "someField",
+          operator: "matches",
+          value: "ticket_fields_12345",
+        },
+        {
+          field: "brandField",
+          operator: "matches",
+          value: "ticket_brand_id",
+        },
+      ],
+      any: [],
+    };
+    const fields: TicketFieldObject[] = [
+      {
+        id: 12345,
+        name: "Test Field 1",
+        value: "fooValue",
+        error: null,
+        label: "Test Field 1",
+        required: false,
+        description: "",
+        type: "text",
+        options: [],
+      },
+    ];
+
+    const result = buildAdvancedDynamicFilterParams(filter, fields);
+
+    expect(result).toEqual([
+      { key: "ticket_fields_12345", value: "fooValue" },
+      { key: "ticket_brand_id", value: null },
+    ]);
+  });
+
   it("returns multiple filters if more than one matches", () => {
     const filter: LookupRelationshipFieldFilter = {
       all: [

src/modules/ticket-fields/fields/LookupField.test.tsx

@@ -52,6 +52,7 @@ export interface LookupFieldProps {
   field: TicketFieldObject;
   userId: number;
   organizationId: string | null;
+  brandId?: number;
   onChange: (value: string) => void;
   visibleFields: TicketFieldObject[];
   buildLookupFieldOptions?: (
@@ -65,6 +66,7 @@ export function LookupField({
   field,
   userId,
   organizationId,
+  brandId,
   onChange,
   visibleFields,
   buildLookupFieldOptions,
@@ -144,13 +146,23 @@ export function LookupField({
       );
 
       for (const { key: filterValue, value: fieldValue } of filterPairs) {
-        if (filterValue) {
+        if (filterValue && filterValue.startsWith("ticket_fields_")) {
           const filterValueParam = `filter[dynamic_values][${filterValue}]`;
           const fieldValueParam = fieldValue?.toString() || "";
           searchParams.set(filterValueParam, fieldValueParam);
         }
       }
 
+      const hasBrandFilter = filterPairs.some(
+        ({ key }) => key === "ticket_brand_id"
+      );
+      if (brandId && hasBrandFilter) {
+        searchParams.set(
+          "filter[dynamic_values][ticket_brand_id]",
+          brandId.toString()
+        );
+      }
+
       if (organizationId) searchParams.set("organization_id", organizationId);
 
       setIsLoadingOptions(true);
@@ -194,6 +206,7 @@ export function LookupField({
       }
     },
     [
+      brandId,
       customObjectKey,
       field,
       fieldId,