fix: handle blob URL downloads for history CSV export

package.json

@@ -27,11 +27,13 @@
     "expo-constants": "~18.0.9",
     "expo-dev-client": "^6.0.17",
     "expo-device": "~8.0.9",
+    "expo-file-system": "~19.0.21",
     "expo-haptics": "^15.0.7",
     "expo-local-authentication": "~17.0.7",
     "expo-navigation-bar": "~5.0.8",
     "expo-notifications": "~0.32.12",
     "expo-secure-store": "~15.0.7",
+    "expo-sharing": "~14.0.8",
     "expo-splash-screen": "~31.0.10",
     "expo-status-bar": "^3.0.8",
     "expo-store-review": "~9.0.8",

src/lib/download.ts

@@ -0,0 +1,54 @@
+/**
+ * Injected JavaScript to intercept blob URL creation for file downloads.
+ * When the web app creates a blob URL for a downloadable file (like CSV export),
+ * this script converts the blob to base64 and sends it to the native app
+ * via postMessage for proper file handling using expo-file-system and expo-sharing.
+ */
+export const injectedJavaScript = `
+  ;(function() {
+    const originalCreateObjectURL = URL.createObjectURL;
+    URL.createObjectURL = function(blob) {
+      const url = originalCreateObjectURL.call(URL, blob);
+
+      // Check if this is a downloadable file type
+      const downloadableTypes = [
+        'text/csv',
+        'application/csv',
+        'application/octet-stream',
+        'text/plain',
+        'application/json'
+      ];
+
+      if (blob instanceof Blob && downloadableTypes.includes(blob.type)) {
+        const reader = new FileReader();
+        reader.onloadend = function() {
+          if (reader.result && typeof reader.result === 'string') {
+            const base64 = reader.result.split(',')[1];
+            if (base64 && window.ReactNativeWebView) {
+              // Determine filename and extension based on MIME type
+              const mimeToExt = {
+                'text/csv': '.csv',
+                'application/csv': '.csv',
+                'application/json': '.json',
+                'text/plain': '.txt',
+                'application/octet-stream': '.csv' // Default to CSV for history export
+              };
+              const ext = mimeToExt[blob.type] || '.csv';
+              const filename = 'transaction-history' + ext;
+
+              window.ReactNativeWebView.postMessage(JSON.stringify({
+                cmd: 'downloadFile',
+                data: base64,
+                filename: filename,
+                mimeType: blob.type || 'application/octet-stream'
+              }));
+            }
+          }
+        };
+        reader.readAsDataURL(blob);
+      }
+
+      return url;
+    };
+  })();
+`

src/lib/getMessageManager.ts

@@ -1,7 +1,10 @@
 /* Register message handlers and injected JavaScript */
 import * as Clipboard from 'expo-clipboard'
+import { File as ExpoFile, Paths } from 'expo-file-system'
+import * as Sharing from 'expo-sharing'
 import once from 'lodash.once'
 import { injectedJavaScript as injectedJavaScriptClipboard } from './clipboard'
+import { injectedJavaScript as injectedJavaScriptDownload } from './download'
 import * as StoreReview from 'expo-store-review'
 import * as Application from 'expo-application'
 
@@ -32,6 +35,9 @@ export const getMessageManager = once(() => {
   console.log('[App] Injecting clipboard JavaScript')
   messageManager.registerInjectedJavaScript(injectedJavaScriptClipboard)
 
+  console.log('[App] Injecting download JavaScript')
+  messageManager.registerInjectedJavaScript(injectedJavaScriptDownload)
+
   const walletManager = getWalletManager()
 
   messageManager.on('console', onConsole)
@@ -56,6 +62,29 @@ export const getMessageManager = once(() => {
   // clipboard
   messageManager.on('setClipboard', evt => Clipboard.setStringAsync(evt.key))
 
+  // file download/sharing
+  messageManager.on('downloadFile', async evt => {
+    try {
+      const { data, filename, mimeType } = evt as unknown as {
+        data: string
+        filename: string
+        mimeType: string
+      }
+
+      const file = new ExpoFile(Paths.cache, filename)
+      file.write(data, { encoding: 'base64' })
+
+      if (await Sharing.isAvailableAsync()) {
+        await Sharing.shareAsync(file.uri, { mimeType })
+      }
+
+      return { success: true }
+    } catch (error) {
+      console.error('[downloadFile:Error]', error)
+      return { success: false, error: String(error) }
+    }
+  })
+
   // expo token for push notifications
   messageManager.on('getExpoToken', async () => {
     try {

src/lib/navigationFilter.ts

@@ -38,6 +38,12 @@ export const shouldLoadFilter = (request: ShouldStartLoadRequest) => {
     return true
   }
 
+  // Handle blob URLs - these are handled by injected JavaScript in download.ts
+  // which intercepts URL.createObjectURL and sends file data via postMessage
+  if (request.url.startsWith('blob:')) {
+    return false
+  }
+
   // External navigation
   openBrowser(request.url).catch(r => {
     console.error(`rejection opening in browser url "${request.url}": `, r)

yarn.lock

@@ -10458,6 +10458,16 @@ __metadata:
   languageName: node
   linkType: hard
 
+"expo-file-system@npm:~19.0.21":
+  version: 19.0.21
+  resolution: "expo-file-system@npm:19.0.21"
+  peerDependencies:
+    expo: "*"
+    react-native: "*"
+  checksum: 26b4c95c8d30580723995bf8e32287b72eadf0e3442ca14854c15dc47021c4c22eefbc490ab4fadf98b3f0b14847eba3012dfe663c8a8b42de7b1587f6811d8f
+  languageName: node
+  linkType: hard
+
 "expo-font@npm:~14.0.9":
   version: 14.0.9
   resolution: "expo-font@npm:14.0.9"
@@ -10598,6 +10608,15 @@ __metadata:
   languageName: node
   linkType: hard
 
+"expo-sharing@npm:~14.0.8":
+  version: 14.0.8
+  resolution: "expo-sharing@npm:14.0.8"
+  peerDependencies:
+    expo: "*"
+  checksum: 8ac54d82328141dc67add5b9db3f16253b42e0e0aa2d39589fffd4d9cf15067e10262b0ab21837b184caae2799de81d74f8b2d129886c50e25550ef4fc6919f3
+  languageName: node
+  linkType: hard
+
 "expo-splash-screen@npm:~31.0.10":
   version: 31.0.10
   resolution: "expo-splash-screen@npm:31.0.10"
@@ -16520,11 +16539,13 @@ __metadata:
     expo-constants: ~18.0.9
     expo-dev-client: ^6.0.17
     expo-device: ~8.0.9
+    expo-file-system: ~19.0.21
     expo-haptics: ^15.0.7
     expo-local-authentication: ~17.0.7
     expo-navigation-bar: ~5.0.8
     expo-notifications: ~0.32.12
     expo-secure-store: ~15.0.7
+    expo-sharing: ~14.0.8
     expo-splash-screen: ~31.0.10
     expo-status-bar: ^3.0.8
     expo-store-review: ~9.0.8