Check HTML-encoded quotes when handling translations for embedded pages (such as welcome.html) (#30743)

* Check HTML encoding on embedded page

* Add tests

* lint

src/components/structures/EmbeddedPage.tsx

@@ -72,7 +72,11 @@ export default class EmbeddedPage extends React.PureComponent<IProps, IState> {
             return;
         }
 
-        let body = (await res.text()).replace(/_t\(['"]([\s\S]*?)['"]\)/gm, (match, g1) => this.translate(g1));
+        // Replace '," and HTML encoded variants
+        let body = (await res.text()).replace(
+            /_t\((?:['"]|(?:&#(?:34|27);))([\s\S]*?)(?:['"]|(?:&#(?:34|27);))\)/gm,
+            (match, g1) => this.translate(g1),
+        );
 
         if (this.props.replaceMap) {
             Object.keys(this.props.replaceMap).forEach((key) => {

test/unit-tests/components/views/context_menus/EmbeddedPage-test.tsx

@@ -19,10 +19,10 @@ jest.mock("../../../../../src/languageHandler", () => ({
 }));
 
 describe("<EmbeddedPage />", () => {
-    it("should translate _t strings", async () => {
+    it.each([`"`, `'`, `&#x27;`, `&#x34;`])("should translate _t strings", async (character) => {
         mocked(_t).mockReturnValue("Przeglądaj pokoje");
         fetchMock.get("https://home.page", {
-            body: '<h1>_t("Explore rooms")</h1>',
+            body: `<h1>_t(${character}Explore rooms${character})</h1>`,
         });
 
         const { asFragment } = render(<EmbeddedPage url="https://home.page" />);

test/unit-tests/components/views/context_menus/__snapshots__/EmbeddedPage-test.tsx.snap

@@ -41,3 +41,51 @@ exports[`<EmbeddedPage /> should translate _t strings 1`] = `
   </div>
 </DocumentFragment>
 `;
+
+exports[`<EmbeddedPage /> should translate _t strings 2`] = `
+<DocumentFragment>
+  <div
+    class="undefined_guest"
+  >
+    <div
+      class="undefined_body"
+    >
+      <h1>
+        Przeglądaj pokoje
+      </h1>
+    </div>
+  </div>
+</DocumentFragment>
+`;
+
+exports[`<EmbeddedPage /> should translate _t strings 3`] = `
+<DocumentFragment>
+  <div
+    class="undefined_guest"
+  >
+    <div
+      class="undefined_body"
+    >
+      <h1>
+        Przeglądaj pokoje
+      </h1>
+    </div>
+  </div>
+</DocumentFragment>
+`;
+
+exports[`<EmbeddedPage /> should translate _t strings 4`] = `
+<DocumentFragment>
+  <div
+    class="undefined_guest"
+  >
+    <div
+      class="undefined_body"
+    >
+      <h1>
+        Przeglądaj pokoje
+      </h1>
+    </div>
+  </div>
+</DocumentFragment>
+`;