Create helper to build public widget options for Dropdown (#2166)

## Summary:
Adds a function that takes Dropdown's full widget options and filters out answer data. It also adds this function to Dropdown's widget export and adds a test confirming the function does what is expected.

Issue: LEMS-2757

## Test plan:
- Confirm all checks pass
- Confirm Dropdown still works as expected

Author: Myranae

Reviewers: benchristel, jeremywiebe, handeyeco

Required Reviewers:

Approved By: benchristel

Checks: ✅ Publish npm snapshot (ubuntu-latest, 20.x), ✅ Lint, Typecheck, Format, and Test (ubuntu-latest, 20.x), ✅ Cypress (ubuntu-latest, 20.x), ✅ Check for .changeset entries for all changed files (ubuntu-latest, 20.x), ✅ Check builds for changes in size (ubuntu-latest, 20.x), ✅ Publish Storybook to Chromatic (ubuntu-latest, 20.x)

Pull Request URL: #2166

.changeset/twelve-spies-lie.md

@@ -0,0 +1,6 @@
+---
+"@khanacademy/perseus": minor
+"@khanacademy/perseus-core": minor
+---
+
+Implement a widget export function to filter out rubric data from widget options for the Dropdown widget

packages/perseus-core/src/index.ts

@@ -117,3 +117,4 @@ export {default as getCategorizerPublicWidgetOptions} from "./widgets/categorize
 export {default as getExpressionPublicWidgetOptions} from "./widgets/expression/expression-util";
 export {default as getLabelImagePublicWidgetOptions} from "./widgets/label-image/label-image-util";
 export {default as getSorterPublicWidgetOptions} from "./widgets/sorter/sorter-util";
+export {default as getDropdownPublicWidgetOptions} from "./widgets/dropdown/dropdown-util";

packages/perseus-core/src/widgets/dropdown/dropdown-util.test.ts

@@ -0,0 +1,32 @@
+import getDropdownPublicWidgetOptions from "./dropdown-util";
+
+import type {PerseusDropdownWidgetOptions} from "../../data-schema";
+
+describe("getDropdownPublicWidgetOptions", () => {
+    it("should return the correct public options without any answer data", () => {
+        // Arrange
+        const options: PerseusDropdownWidgetOptions = {
+            choices: [
+                {content: "1", correct: false},
+                {content: "2", correct: false},
+                {content: "3", correct: true},
+            ],
+            placeholder: "Select an option",
+            static: false,
+            visibleLabel: "Test Label",
+            ariaLabel: "Test Aria Label",
+        };
+
+        // Act
+        const publicWidgetOptions = getDropdownPublicWidgetOptions(options);
+
+        // Assert
+        expect(publicWidgetOptions).toEqual({
+            choices: [{content: "1"}, {content: "2"}, {content: "3"}],
+            placeholder: "Select an option",
+            static: false,
+            visibleLabel: "Test Label",
+            ariaLabel: "Test Aria Label",
+        });
+    });
+});

packages/perseus-core/src/widgets/dropdown/dropdown-util.ts

@@ -0,0 +1,31 @@
+import type {PerseusDropdownWidgetOptions} from "@khanacademy/perseus-core";
+
+/**
+ * For details on the individual options, see the
+ * PerseusDropdownWidgetOptions type
+ */
+type DropdownPublicWidgetOptions = {
+    choices: ReadonlyArray<{content: string}>;
+    placeholder: PerseusDropdownWidgetOptions["placeholder"];
+    static: PerseusDropdownWidgetOptions["static"];
+    visibleLabel?: PerseusDropdownWidgetOptions["visibleLabel"];
+    ariaLabel?: PerseusDropdownWidgetOptions["ariaLabel"];
+};
+
+/**
+ * Given a PerseusDropdownWidgetOptions object, return a new object with only
+ * the public options that should be exposed to the client.
+ */
+function getDropdownPublicWidgetOptions(
+    options: PerseusDropdownWidgetOptions,
+): DropdownPublicWidgetOptions {
+    return {
+        choices: options.choices.map((choice) => ({content: choice.content})),
+        placeholder: options.placeholder,
+        static: options.static,
+        visibleLabel: options.visibleLabel,
+        ariaLabel: options.ariaLabel,
+    };
+}
+
+export default getDropdownPublicWidgetOptions;

packages/perseus/src/types.ts

@@ -17,6 +17,7 @@ import type {
     getCategorizerPublicWidgetOptions,
     getExpressionPublicWidgetOptions,
     getSorterPublicWidgetOptions,
+    getDropdownPublicWidgetOptions,
 } from "@khanacademy/perseus-core";
 import type {LinterContextProps} from "@khanacademy/perseus-linter";
 import type {
@@ -543,6 +544,7 @@ export type WidgetScorerFunction = (
  * A union type of all the functions that provide public widget options.
  */
 export type PublicWidgetOptionsFunction =
+    | typeof getDropdownPublicWidgetOptions
     | typeof getCategorizerPublicWidgetOptions
     | typeof getOrdererPublicWidgetOptions
     | typeof getExpressionPublicWidgetOptions

packages/perseus/src/widgets/dropdown/dropdown.tsx

@@ -1,3 +1,4 @@
+import {getDropdownPublicWidgetOptions} from "@khanacademy/perseus-core";
 import {scoreDropdown, validateDropdown} from "@khanacademy/perseus-score";
 import {Id, View} from "@khanacademy/wonder-blocks-core";
 import {SingleSelect, OptionItem} from "@khanacademy/wonder-blocks-dropdown";
@@ -176,4 +177,5 @@ export default {
     // TODO(LEMS-2656): remove TS suppression
     // @ts-expect-error: Type 'UserInput' is not assignable to type 'PerseusDropdownUserInput'.
     validator: validateDropdown,
+    getPublicWidgetOptions: getDropdownPublicWidgetOptions,
 } satisfies WidgetExports<typeof Dropdown>;