fix overwriting default options for decoding and add tests

Author: haschek

src/common/utils/reduceToText.tsx

@@ -58,7 +58,10 @@ export const reduceToText: ReduceToTextFuncType = (input, options) => {
             .split(" ")
             .map((value) => {
                 try {
-                    return utils.decodeHtmlEntities(value, { ...decodeDefaultOptions });
+                    return utils.decodeHtmlEntities(value, {
+                        ...decodeDefaultOptions,
+                        ...options?.decodeHtmlEntitiesOptions,
+                    });
                 } catch {
                     decodeErrors++;
                     return value;

src/components/TextReducer/TextReducer.test.tsx

@@ -0,0 +1,38 @@
+import React from "react";
+import { render } from "@testing-library/react";
+
+import "@testing-library/jest-dom";
+
+import { Markdown, TextReducer } from "./../../";
+import { Default as TextReducerStory } from "./TextReducer.stories";
+
+describe("TextReducer", () => {
+    it("should display encoded HTML entities by default if they are used in the transformed markup", () => {
+        const { queryByText } = render(<TextReducer {...TextReducerStory.args} />);
+        expect(queryByText("&#x27;entities&#x27; &amp; &quot;quotes&quot;", { exact: false })).not.toBeNull();
+        expect(queryByText(`'entities' & "quotes"`, { exact: false })).toBeNull();
+    });
+    it("should not display encoded HTML entities if `decodeHtmlEntities` is enabled", () => {
+        const { queryByText } = render(<TextReducer {...TextReducerStory.args} decodeHtmlEntities />);
+        expect(queryByText("&#x27;entities&#x27; &amp; &quot;quotes&quot;", { exact: false })).toBeNull();
+        expect(queryByText(`'entities' & "quotes"`, { exact: false })).not.toBeNull();
+    });
+    it("should only decode if correct encoded HTML entities are found (strict mode)", () => {
+        const { queryByText } = render(
+            <TextReducer decodeHtmlEntities>
+                <Markdown>&</Markdown>&amp foo&ampbar
+            </TextReducer>
+        );
+        expect(queryByText("& &amp foo&ampbar", { exact: false })).not.toBeNull();
+        expect(queryByText("& & foo&ampbar", { exact: false })).toBeNull();
+    });
+    it("should allow decoding non-strict encoded HTML entities", () => {
+        const { queryByText } = render(
+            <TextReducer decodeHtmlEntities decodeHtmlEntitiesOptions={{ strict: false }}>
+                <Markdown>&</Markdown>&amp foo&ampbar
+            </TextReducer>
+        );
+        expect(queryByText("& &amp foo&ampbar", { exact: false })).toBeNull();
+        expect(queryByText("& & foo&ampbar", { exact: false })).not.toBeNull();
+    });
+});