dcc: refactor dropdown

@plotly/dash-generator-test-component-typescript/generator.test.ts

@@ -197,6 +197,28 @@ describe('Test Typescript component metadata generation', () => {
             expect(propType.value.value[0].name).toBe('string');
             expect(propType.value.value[1].name).toBe('shape');
         });
+        test('Union of primitives and arrays of primitives', () => {
+            const propType = R.path(
+                propPath('TypeScriptComponent', 'array_primitive_mix').concat(
+                    'type'
+                ),
+                metadata
+            );
+            expect(propType.name).toBe('union');
+            expect(propType.value.length).toBe(4);
+            expect(propType.value[0].name).toBe('string');
+            expect(propType.value[1].name).toBe('number');
+            expect(propType.value[2].name).toBe('bool');
+            expect(propType.value[3].name).toBe('arrayOf');
+
+            // Verify that the array element type is a union of string, number, and boolean
+            const arrayElementType = propType.value[3].value;
+            expect(arrayElementType.name).toBe('union');
+            expect(arrayElementType.value.length).toBe(3);
+            expect(arrayElementType.value[0].name).toBe('string');
+            expect(arrayElementType.value[1].name).toBe('number');
+            expect(arrayElementType.value[2].name).toBe('bool');
+        });
         test('Obj properties', () => {
             const propType = R.path(
                 propPath('TypeScriptComponent', 'obj').concat('type', 'value'),

@plotly/dash-generator-test-component-typescript/src/components/TypeScriptComponent.tsx

@@ -12,6 +12,7 @@ const TypeScriptComponent = ({
   bool_default = true,
   null_default = null,
   obj_default = { a: 'a', b: 3 },
+  array_primitive_mix = 1,
   ...props
 }: TypescriptComponentProps) => {
   return <div id={id}>{required_string}</div>;

@plotly/dash-generator-test-component-typescript/src/props.ts

@@ -29,6 +29,11 @@ export type TypescriptComponentProps = {
     union?: number | string;
     union_shape?: {a: string} | string;
     array_union_shape?: ({a: string} | string)[];
+    array_primitive_mix?:
+        | string
+        | number
+        | (string | number | boolean)[]
+        | boolean;
     element?: JSX.Element;
     array_elements?: JSX.Element[];
 

CHANGELOG.md

@@ -2,6 +2,11 @@
 All notable changes to `dash` will be documented in this file.
 This project adheres to [Semantic Versioning](https://semver.org/).
 
+## [UNRELEASED]
+
+## Added
+- [#3440](https://github.com/plotly/dash/pull/3440) Modernize dcc.Dropdown
+
 ## [4.0.0rc0] - 2025-09-11
 - [#3398](https://github.com/plotly/dash/pull/3398) Modernize dcc.Input
 - [#3414](https://github.com/plotly/dash/pull/3414) Modernize dcc.Slider