Ensure PDF cache fallback is sanitized

Author: gumclaw

app/pdf-viewer.tsx

@@ -9,7 +9,7 @@ import { useRefToLatest } from "@/components/use-ref-to-latest";
 import { useAuth } from "@/lib/auth-context";
 import { cacheFileDestination } from "@/lib/file-utils";
 import { updateMediaLocation } from "@/lib/media-location";
-import { File, Paths } from "expo-file-system";
+import { File } from "expo-file-system";
 import * as Sharing from "expo-sharing";
 import * as Sentry from "@sentry/react-native";
 import { useQueryClient } from "@tanstack/react-query";
@@ -54,7 +54,7 @@ export default function PdfViewerScreen() {
   const [isDownloading, setIsDownloading] = useState(true);
 
   const downloadDestination = useCallback(
-    () => (productFileId ? cacheFileDestination(productFileId, fileName ?? DEFAULT_PDF_FILE_NAME) : Paths.cache),
+    () => cacheFileDestination(productFileId ?? "pdf-viewer", fileName ?? DEFAULT_PDF_FILE_NAME),
     [productFileId, fileName],
   );
 

tests/app/pdf-viewer.test.tsx

@@ -1,13 +1,23 @@
 import { fireEvent, screen, waitFor } from "@testing-library/react-native";
 import { renderWithQueryClient } from "../render-with-query-client";
 
+type MockSearchParams = {
+  uri: string;
+  title?: string;
+  fileName?: string;
+  productFileId?: string;
+};
+
+const defaultSearchParams: MockSearchParams = {
+  uri: "https://example.com/test.pdf",
+  title: "Test PDF",
+  fileName: "HOW TO BECOME AN ELITE PLAYER AND BE BETTER THAN 99%.pdf",
+  productFileId: "pf1",
+};
+let mockSearchParams: MockSearchParams = { ...defaultSearchParams };
+
 jest.mock("expo-router", () => ({
-  useLocalSearchParams: () => ({
-    uri: "https://example.com/test.pdf",
-    title: "Test PDF",
-    fileName: "HOW TO BECOME AN ELITE PLAYER AND BE BETTER THAN 99%.pdf",
-    productFileId: "pf1",
-  }),
+  useLocalSearchParams: () => mockSearchParams,
   Stack: {
     Screen: ({ options }: { options?: { headerRight?: () => React.ReactNode } }) => {
       const React = require("react");
@@ -101,6 +111,7 @@ describe("PdfViewerScreen", () => {
   beforeEach(() => {
     const { File } = require("expo-file-system");
     const Sharing = require("expo-sharing");
+    mockSearchParams = { ...defaultSearchParams };
     mockOnError = null;
     File.downloadFileAsync.mockReset();
     File.downloadFileAsync.mockResolvedValue({ uri: "file:///cache/test.pdf" });
@@ -207,6 +218,24 @@ describe("PdfViewerScreen", () => {
     expect(destination.uri).not.toContain("%");
   });
 
+  it("downloads to a sanitized fallback cache destination when product file id is missing", async () => {
+    const { File } = require("expo-file-system");
+    mockSearchParams = {
+      uri: "https://example.com/test.pdf",
+      title: "Test PDF",
+      fileName: "100% bonus #1.pdf",
+    };
+
+    renderWithProviders();
+
+    await waitFor(() => expect(screen.getByTestId("pdf-component")).toBeTruthy());
+
+    const destination = File.downloadFileAsync.mock.calls[0][1];
+    expect(destination.uri).toBe("/cache/pdf-viewer/100_ bonus _1.pdf");
+    expect(destination.uri).not.toContain("%");
+    expect(destination.uri).not.toContain("#");
+  });
+
   it("shares the cached PDF file when available", async () => {
     const { File } = require("expo-file-system");
     const Sharing = require("expo-sharing");