fix: handle all supported date value types in date picker (#2956)

src/app/shared/form/builder/ds-dynamic-form-ui/models/date-picker/date-picker.component.spec.ts

@@ -206,6 +206,44 @@ describe('DsDatePickerComponent test suite', () => {
       });
     });
 
+    describe('when init model value is a Date object', () => {
+      beforeEach(() => {
+        dateFixture = TestBed.createComponent(DsDatePickerComponent);
+        dateComp = dateFixture.componentInstance;
+        dateComp.group = DATE_TEST_GROUP;
+        dateComp.model = new DynamicDsDatePickerModel(DATE_TEST_MODEL_CONFIG);
+        dateComp.model.value = new Date(Date.UTC(1983, 10, 18));
+        dateFixture.detectChanges();
+      });
+
+      it('should init component properly from a Date object', () => {
+        expect(dateComp.year).toBe(1983);
+        expect(dateComp.month).toBe(11);
+        expect(dateComp.day).toBe(18);
+        expect(dateComp.disabledMonth).toBeFalsy();
+        expect(dateComp.disabledDay).toBeFalsy();
+      });
+    });
+
+    describe('when init model value is a NgbDateStruct-like object', () => {
+      beforeEach(() => {
+        dateFixture = TestBed.createComponent(DsDatePickerComponent);
+        dateComp = dateFixture.componentInstance;
+        dateComp.group = DATE_TEST_GROUP;
+        dateComp.model = new DynamicDsDatePickerModel(DATE_TEST_MODEL_CONFIG);
+        dateComp.model.value = { year: 1983, month: 11, day: 18 };
+        dateFixture.detectChanges();
+      });
+
+      it('should init component properly from a NgbDateStruct-like object', () => {
+        expect(dateComp.year).toBe(1983);
+        expect(dateComp.month).toBe(11);
+        expect(dateComp.day).toBe(18);
+        expect(dateComp.disabledMonth).toBeFalsy();
+        expect(dateComp.disabledDay).toBeFalsy();
+      });
+    });
+
     describe('when init model value is not empty', () => {
       beforeEach(() => {
 

src/app/shared/form/builder/ds-dynamic-form-ui/models/date-picker/date-picker.component.ts

@@ -14,6 +14,7 @@ import {
   FormsModule,
   UntypedFormGroup,
 } from '@angular/forms';
+import { dateValueToString } from '@dspace/shared/utils/date.util';
 import { hasValue } from '@dspace/shared/utils/empty.util';
 import {
   DynamicFormControlComponent,
@@ -89,9 +90,7 @@ export class DsDatePickerComponent extends DynamicFormControlComponent implement
     this.initialDay = now.getUTCDate();
 
     if (this.model && this.model.value !== null) {
-      // todo: model value could object or Date according to its type annotation
-      // eslint-disable-next-line @typescript-eslint/no-base-to-string
-      const values = this.model.value.toString().split(DS_DATE_PICKER_SEPARATOR);
+      const values = dateValueToString(this.model.value).split(DS_DATE_PICKER_SEPARATOR);
       if (values.length > 0) {
         this.initialYear = parseInt(values[0], 10);
         this.year = this.initialYear;

src/app/shared/form/builder/parsers/date-field-parser.ts

@@ -1,4 +1,5 @@
 import { FormFieldMetadataValueObject } from '@dspace/core/shared/form/models/form-field-metadata-value.model';
+import { dateValueToString } from '@dspace/shared/utils/date.util';
 import { isNotEmpty } from '@dspace/shared/utils/empty.util';
 
 import { DS_DATE_PICKER_SEPARATOR } from '../ds-dynamic-form-ui/models/date-picker/date-picker.component';
@@ -19,9 +20,7 @@ export class DateFieldParser extends FieldParser {
     this.setValues(inputDateModelConfig as any, fieldValue);
     // Init Data and validity check
     if (isNotEmpty(inputDateModelConfig.value)) {
-      // todo: model value could be object or Date according to its type annotation
-      // eslint-disable-next-line @typescript-eslint/no-base-to-string
-      const value = inputDateModelConfig.value.toString();
+      const value = dateValueToString(inputDateModelConfig.value);
       if (value.length >= 4) {
         const valuesArray = value.split(DS_DATE_PICKER_SEPARATOR);
         if (valuesArray.length < 4) {

src/app/utils/date.util.spec.ts

@@ -2,6 +2,7 @@ import {
   dateToISOFormat,
   dateToNgbDateStruct,
   dateToString,
+  dateValueToString,
   isValidDate,
   yearFromString,
 } from './date.util';
@@ -93,6 +94,24 @@ describe('Date Utils', () => {
     });
   });
 
+  describe('dateValueToString', () => {
+    it('should return the same string when given a string', () => {
+      expect(dateValueToString('1983-11-18')).toEqual('1983-11-18');
+    });
+    it('should return YYYY-MM-DD when given a Date object', () => {
+      expect(dateValueToString(new Date(Date.UTC(1983, 10, 18)))).toEqual('1983-11-18');
+    });
+    it('should return YYYY-MM-DD when given a NgbDateStruct-like object', () => {
+      expect(dateValueToString({ year: 1983, month: 11, day: 18 })).toEqual('1983-11-18');
+    });
+    it('should throw an error for an arbitrary object', () => {
+      expect(() => dateValueToString({ foo: 'bar' })).toThrowError(/Unsupported date value type/);
+    });
+    it('should throw an error for an empty object', () => {
+      expect(() => dateValueToString({})).toThrowError(/Unsupported date value type/);
+    });
+  });
+
   describe('yearFromString', () => {
     it('should return year from YYYY string', () => {
       expect(yearFromString('2022')).toEqual(2022);

src/app/utils/date.util.ts

@@ -108,3 +108,29 @@ export function yearFromString(date: string) {
   return isValidDate(date) ? new Date(date).getUTCFullYear() : null;
 }
 
+/**
+ * Converts a date model value (string | Date | object) to a YYYY-MM-DD formatted string.
+ *
+ * The dynamic form library defines date values as string | object | Date.
+ * This function safely handles all supported types and throws an informative
+ * error if an unsupported object type is encountered.
+ *
+ * @param value The date value to convert
+ * @returns The date as a string (e.g. "1983-11-18")
+ * @throws Error if value is an object without year/month/day properties
+ */
+export function dateValueToString(value: string | Date | object): string {
+  if (typeof value === 'string') {
+    return value;
+  }
+  if (value instanceof Date) {
+    return dateToString(value);
+  }
+  if (isNgbDateStruct(value)) {
+    return dateToString(value as NgbDateStruct);
+  }
+  throw new Error(
+    `Unsupported date value type: expected a string, Date, or object with {year, month, day} properties, but received: ${JSON.stringify(value)}`,
+  );
+}
+