test: add test behavior to back button

__mocks__/jest.setup.js

@@ -9,12 +9,21 @@ import "jest-location-mock";
 
 global.plausible = null;
 
+let history = [];
+
 window.history.pushState = (data, unused, url) => {
 	window.location.assign(url);
+	history.push(url);
 };
 
 window.history.replaceState = (data, unused, url) => {
 	window.location.assign(url);
+	history[history.length - 1] = url;
+};
+
+window.history.back = () => {
+	history.pop();
+	window.location.assign(history[history.length - 1]);
 };
 
 global.IntersectionObserver = class IntersectionObserver {

src/views/search/search-page.spec.tsx

@@ -1129,5 +1129,35 @@ describe("Search page", () => {
 		);
 	});
 
-	test.todo("Back button should show last query");
+	test("Back button should show last query", async () => {
+		mockFetch(() => ({
+			posts: [],
+			totalPosts: 0,
+			totalCollections: 0,
+			collections: [],
+		}));
+
+		const { getByTestId, getByText, getByLabelText, queryByText } = render(
+			<SearchPage unicornProfilePicMap={[]} />,
+		);
+
+		const searchInput = getByLabelText("Search");
+		await user.type(searchInput, "blog");
+
+		await waitFor(() =>
+			expect(getByText("No results found...")).toBeInTheDocument(),
+		);
+
+		await user.type(searchInput, "other");
+
+		await waitFor(() =>
+			expect(window.location.search).toBe("?searchQuery=blogother"),
+		);
+
+		history.back();
+
+		await waitFor(() =>
+			expect(window.location.search).toBe("?searchQuery=blog"),
+		);
+	});
 });