Stop exposing app data to the iOS Files app

jest/setup.ts

@@ -121,7 +121,14 @@ jest.mock('react-native-fs', () => ({
                 res([]);
             }),
     ),
-    CachesDirectoryPath: jest.fn(),
+    exists: jest.fn(() => Promise.resolve(false)),
+    mkdir: jest.fn(() => Promise.resolve()),
+    moveFile: jest.fn(() => Promise.resolve()),
+    copyFile: jest.fn(() => Promise.resolve()),
+    writeFile: jest.fn(() => Promise.resolve()),
+    DocumentDirectoryPath: '/mock/documents',
+    CachesDirectoryPath: '/mock/caches',
+    LibraryDirectoryPath: '/mock/library',
 }));
 
 jest.mock('react-native-share', () => ({

patches/react-native-nitro-sqlite/details.md

@@ -0,0 +1,16 @@
+# `react-native-nitro-sqlite` patches
+
+### [react-native-nitro-sqlite+9.6.0+001+store-database-outside-documents.patch](react-native-nitro-sqlite+9.6.0+001+store-database-outside-documents.patch)
+
+- Reason:
+
+    ```
+    The library stores SQLite databases in the iOS Documents directory, which is exposed to users
+    via the Files app when file sharing is enabled. This patch stores databases in
+    Library/Application Support instead (persistent, backed up, never user-visible) and migrates
+    databases created by older app versions out of Documents on first launch.
+    ```
+
+- Upstream PR/issue: https://github.com/margelo/react-native-nitro-sqlite/issues/289
+- E/App issue: https://github.com/Expensify/App/issues/96649
+- PR introducing patch: https://github.com/Expensify/App/pull/96531

patches/react-native-nitro-sqlite/react-native-nitro-sqlite+9.6.0+001+store-database-outside-documents.patch

@@ -0,0 +1,59 @@
+diff --git a/node_modules/react-native-nitro-sqlite/ios/OnLoad.mm b/node_modules/react-native-nitro-sqlite/ios/OnLoad.mm
+index 6ce7258..38ea210 100644
+--- a/node_modules/react-native-nitro-sqlite/ios/OnLoad.mm
++++ b/node_modules/react-native-nitro-sqlite/ios/OnLoad.mm
+@@ -10,6 +10,33 @@ @implementation OnLoad
+ using namespace margelo::nitro;
+ using namespace margelo::nitro::rnnitrosqlite;
+
++// The Documents directory can be exposed to the user (Files app) when file sharing
++// is enabled, so databases are stored in Library/Application Support instead.
++// Databases created by older app versions are moved out of Documents on first launch.
++static void migrateDatabaseFiles(NSString *fromDirectory, NSString *toDirectory) {
++  NSFileManager *fileManager = [NSFileManager defaultManager];
++  NSArray<NSString *> *files = [fileManager contentsOfDirectoryAtPath:fromDirectory error:nil];
++
++  for (NSString *file in files) {
++    // Covers the database itself plus its -wal/-shm journal files
++    if (![file hasPrefix:@"OnyxDB"]) {
++      continue;
++    }
++
++    NSString *sourcePath = [fromDirectory stringByAppendingPathComponent:file];
++    NSString *destinationPath = [toDirectory stringByAppendingPathComponent:file];
++
++    if ([fileManager fileExistsAtPath:destinationPath]) {
++      continue;
++    }
++
++    NSError *error = nil;
++    if (![fileManager moveItemAtPath:sourcePath toPath:destinationPath error:&error]) {
++      NSLog(@"Failed to migrate database file %@: %@", file, error.localizedDescription);
++    }
++  }
++}
++
+ + (void)load {
+   // Get appGroupID value from Info.plist using key "AppGroup"
+   NSString *appGroupID = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"RNNitroSQLite_AppGroup"];
+@@ -30,9 +57,18 @@ + (void)load {
+
+     documentPath = [storeUrl path];
+   } else {
+-    // Get iOS app's document directory (to safely store database .sqlite3 file)
+-    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, true);
++    // Store databases in Library/Application Support, which is persistent, backed up,
++    // and never exposed to the user via the Files app (unlike the Documents directory)
++    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSApplicationSupportDirectory, NSUserDomainMask, true);
+     documentPath = [paths objectAtIndex:0];
++
++    NSFileManager *fileManager = [NSFileManager defaultManager];
++    if (![fileManager fileExistsAtPath:documentPath]) {
++      [fileManager createDirectoryAtPath:documentPath withIntermediateDirectories:YES attributes:nil error:nil];
++    }
++
++    NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, true);
++    migrateDatabaseFiles([documentPaths objectAtIndex:0], documentPath);
+   }
+
+   HybridNitroSQLite::docPath = [documentPath UTF8String];

src/libs/ExportOnyxState/index.native.ts

@@ -40,7 +40,10 @@ const shareAsFile: ShareAsFile = (fileContent) => {
     try {
         // Define new filename and path for the app info file
         const infoFileName = CONST.DEFAULT_ONYX_DUMP_FILE_NAME;
-        const infoFilePath = `${RNFS.DocumentDirectoryPath}/${infoFileName}`;
+        // The dump only needs to live long enough to be shared, so it goes in Caches, which
+        // is never exposed to the user (unlike Documents, which the iOS Files app shows when
+        // file sharing is enabled) and which the OS can reclaim afterwards
+        const infoFilePath = `${RNFS.CachesDirectoryPath}/${infoFileName}`;
         const actualInfoFile = `file://${infoFilePath}`;
 
         RNFS.writeFile(infoFilePath, fileContent, 'utf8').then(() => {

src/libs/actions/Attachment/index.native.ts

@@ -10,7 +10,9 @@ import Onyx from 'react-native-onyx';
 
 import type {CacheAttachmentProps, GetCachedAttachmentProps, RemoveCachedAttachmentProps} from './types';
 
-const ATTACHMENT_DIR = `${RNFS.DocumentDirectoryPath}/attachments`;
+// Cached attachments are re-downloadable, so they live in Caches, which the OS may purge
+// and which is never exposed to the user via the iOS Files app (unlike Documents)
+const ATTACHMENT_DIR = `${RNFS.CachesDirectoryPath}/attachments`;
 
 async function cacheAttachment({attachmentID, uri, mimeType}: CacheAttachmentProps) {
     const isLocalFile = uri.startsWith('file://');

src/libs/fileDownload/index.ios.ts

@@ -30,26 +30,41 @@ const isUserCancelled = (err: unknown) => {
 };
 
 /**
- * Downloads the file to Documents section in iOS
+ * Downloads the file to the Documents directory, which the iOS Files app shows to the user
+ * as the app's folder because file sharing is enabled. Only files the user asked to download
+ * belong there; internal files must go to a directory the Files app does not expose.
  */
 function downloadFile(fileUrl: string, fileName: string) {
     const dirs = RNFetchBlob.fs.dirs;
 
-    // The iOS files will download to documents directory
-    const path = dirs.DocumentDir;
+    return RNFetchBlob.config({
+        fileCache: true,
+        path: `${dirs.DocumentDir}/${fileName}`,
+    }).fetch('GET', fileUrl);
+}
+
+/**
+ * Downloads the file to the cache directory, for flows that only need a temporary local
+ * copy (e.g. saving to Photos or handing off to the share sheet). Unlike Documents, the
+ * cache directory is never shown to the user in the iOS Files app.
+ */
+function downloadFileToCache(fileUrl: string, fileName: string) {
+    const dirs = RNFetchBlob.fs.dirs;
 
-    // Fetching the attachment
     return RNFetchBlob.config({
         fileCache: true,
-        path: `${path}/${fileName}`,
-        addAndroidDownloads: {
-            useDownloadManager: true,
-            notification: true,
-            path: `${path}/Expensify/${fileName}`,
-        },
+        path: `${dirs.CacheDir}/${fileName}`,
     }).fetch('GET', fileUrl);
 }
 
+/**
+ * Presents the iOS share sheet so the user can save the file to the Files app,
+ * then removes the local copy.
+ */
+function shareFileToFilesApp(localPath: string) {
+    return Share.open({url: localPath, failOnCancel: false, saveToFiles: true}).then(() => RNFS.unlink(localPath));
+}
+
 const postDownloadFile = (translate: LocalizedTranslate, url: string, fileName?: string, formData?: FormData, onDownloadFailed?: () => void, appendTimestamp = true) => {
     const fetchOptions: RequestInit = {
         method: 'POST',
@@ -70,12 +85,12 @@ const postDownloadFile = (translate: LocalizedTranslate, url: string, fileName?:
         .then((fileData) => {
             const resolvedFileName = fileName ?? 'Expensify';
             const finalFileName = appendTimestamp ? appendTimeToFileName(resolvedFileName) : resolvedFileName;
-            const expensifyDir = `${RNFS.DocumentDirectoryPath}/Expensify`;
+            // The file only exists to be handed to the share sheet, so it is written to the
+            // cache directory, which the iOS Files app never shows to the user
+            const expensifyDir = `${RNFS.CachesDirectoryPath}/Expensify`;
             const localPath = `${expensifyDir}/${finalFileName}`;
             return RNFS.mkdir(expensifyDir).then(() => {
-                return RNFS.writeFile(localPath, fileData, 'utf8')
-                    .then(() => Share.open({url: localPath, failOnCancel: false, saveToFiles: true}))
-                    .then(() => RNFS.unlink(localPath));
+                return RNFS.writeFile(localPath, fileData, 'utf8').then(() => shareFileToFilesApp(localPath));
             });
         })
         .catch((error) => {
@@ -102,24 +117,24 @@ function downloadImage(fileUrl: string) {
  */
 function downloadVideo(fileUrl: string, fileName: string): Promise<PhotoIdentifier> {
     return new Promise((resolve, reject) => {
-        let documentPathUri: string | null = null;
+        let tempPathUri: string | null = null;
         let cameraRollAsset: PhotoIdentifier;
 
-        // Because CameraRoll doesn't allow direct downloads of video with remote URIs, we first download as documents, then copy to photo lib and unlink the original file.
-        downloadFile(fileUrl, fileName)
+        // Because CameraRoll doesn't allow direct downloads of video with remote URIs, we first download to the cache, then copy to photo lib and unlink the temporary file.
+        downloadFileToCache(fileUrl, fileName)
             .then((attachment) => {
-                documentPathUri = attachment.data as string | null;
-                if (!documentPathUri) {
+                tempPathUri = attachment.data as string | null;
+                if (!tempPathUri) {
                     throw new Error('Error downloading video');
                 }
-                return CameraRoll.saveAsset(documentPathUri);
+                return CameraRoll.saveAsset(tempPathUri);
             })
             .then((attachment) => {
                 cameraRollAsset = attachment;
-                if (!documentPathUri) {
+                if (!tempPathUri) {
                     throw new Error('Error downloading video');
                 }
-                return RNFetchBlob.fs.unlink(documentPathUri);
+                return RNFetchBlob.fs.unlink(tempPathUri);
             })
             .then(() => {
                 resolve(cameraRollAsset);

src/libs/localFileCreate/index.native.ts

@@ -14,7 +14,10 @@ const localFileCreate: LocalFileCreate = (fileName, textContent, appendTimestamp
     const {fileExtension} = splitExtensionFromFileName(fileName);
     const fileNameWithExtension = fileExtension ? fileName : `${fileName}.txt`;
     const newFileName = appendTimestamp ? appendTimeToFileName(fileNameWithExtension) : fileNameWithExtension;
-    const dir = RNFetchBlob.fs.dirs.DocumentDir;
+    // These files are temporary hand-offs to a share/copy flow that deletes them afterwards,
+    // so they belong in the cache directory, which is never exposed to the user (unlike
+    // Documents, which the iOS Files app shows when file sharing is enabled)
+    const dir = RNFetchBlob.fs.dirs.CacheDir;
     const path = `${dir}/${newFileName}`;
 
     return RNFetchBlob.fs.writeFile(path, textContent, 'utf8').then(() => RNFetchBlob.fs.stat(path).then(({size}) => ({path, newFileName, size})));

src/libs/migrateOnyx.ts

@@ -2,6 +2,7 @@ import CONST from '@src/CONST';
 
 import Log from './Log';
 import ConvertGpsPointsTo2DArray from './migrations/ConvertGpsPointsTo2DArray';
+import MoveFilesOutOfDocuments from './migrations/MoveFilesOutOfDocuments';
 import {endSpan, getSpan, startSpan} from './telemetry/activeSpans';
 
 export default function () {
@@ -16,7 +17,7 @@ export default function () {
         });
 
         // Add all migrations to an array so they are executed in order
-        const migrationPromises: Array<() => Promise<void>> = [ConvertGpsPointsTo2DArray];
+        const migrationPromises: Array<() => Promise<void>> = [ConvertGpsPointsTo2DArray, MoveFilesOutOfDocuments];
 
         // Reduce all promises down to a single promise. All promises run in a linear fashion, waiting for the
         // previous promise to finish before moving onto the next one.

src/libs/migrations/MoveFilesOutOfDocuments/index.ios.ts

@@ -0,0 +1,61 @@
+import Log from '@libs/Log';
+
+import CONST from '@src/CONST';
+import ONYXKEYS from '@src/ONYXKEYS';
+
+import RNFS from 'react-native-fs';
+import Onyx from 'react-native-onyx';
+
+const OLD_ATTACHMENT_DIR = `${RNFS.DocumentDirectoryPath}/attachments`;
+
+/**
+ * The attachment cache now lives in Library/Caches. The old copies in Documents are
+ * deleted rather than moved because cached attachments re-download on demand, and the
+ * Onyx attachment collection is cleared since its sources point at the old directory.
+ */
+function migrateAttachmentCache(): Promise<void> {
+    return RNFS.exists(OLD_ATTACHMENT_DIR).then((exists) => {
+        if (!exists) {
+            return;
+        }
+        return RNFS.unlink(OLD_ATTACHMENT_DIR)
+            .then(() => Onyx.setCollection(ONYXKEYS.COLLECTION.ATTACHMENT, {}))
+            .then(() => {
+                Log.info('[Migrate Onyx] MoveFilesOutOfDocuments removed the old attachment cache');
+            });
+    });
+}
+
+/**
+ * Onyx state dumps were previously written to Documents and never deleted after sharing,
+ * so a stale dump may still sit there. It is an internal debug file, so it is removed.
+ */
+function removeStaleOnyxDump(): Promise<void> {
+    const dumpPath = `${RNFS.DocumentDirectoryPath}/${CONST.DEFAULT_ONYX_DUMP_FILE_NAME}`;
+    return RNFS.exists(dumpPath).then((exists) => {
+        if (!exists) {
+            return;
+        }
+        return RNFS.unlink(dumpPath).then(() => {
+            Log.info('[Migrate Onyx] MoveFilesOutOfDocuments removed a stale Onyx state dump');
+        });
+    });
+}
+
+/**
+ * Internal app files used to live in the Documents directory, which iOS shows to the
+ * user (and other apps) through the Files app because file sharing is enabled. This
+ * removes the ones older app versions left behind, so the directory only holds files
+ * the user expects to see there: their downloads and queued receipt uploads.
+ */
+export default function (): Promise<void> {
+    return (
+        Promise.resolve()
+            .then(() => Promise.all([migrateAttachmentCache(), removeStaleOnyxDump()]))
+            .then(() => undefined)
+            // A failed cleanup must never block app startup; new files already go to the new locations
+            .catch((error) => {
+                Log.warn('[Migrate Onyx] MoveFilesOutOfDocuments failed', {error: error instanceof Error ? error.message : String(error)});
+            })
+    );
+}

src/libs/migrations/MoveFilesOutOfDocuments/index.ts

@@ -0,0 +1,5 @@
+// This migration only applies to iOS, where internal files previously lived in the
+// user-visible Documents directory. On other platforms it is a no-op.
+export default function (): Promise<void> {
+    return Promise.resolve();
+}

tests/actions/AttachmentTest.ts

@@ -16,6 +16,7 @@ import waitForBatchedUpdates from '../utils/waitForBatchedUpdates';
 
 jest.mock('react-native-fs', () => ({
     DocumentDirectoryPath: '/mock/documents',
+    CachesDirectoryPath: '/mock/caches',
     copyFile: jest.fn(() => Promise.resolve()),
     exists: jest.fn(() => Promise.resolve(true)),
     unlink: jest.fn(() => Promise.resolve()),
@@ -104,7 +105,7 @@ describe('AttachmentStorage', () => {
         expect(attachmentID).toBeDefined();
         expect(attachment).toEqual({
             attachmentID,
-            source: `/mock/documents/attachments/${attachmentID}.jpg`,
+            source: `/mock/caches/attachments/${attachmentID}.jpg`,
         });
     });
     it('should cache markdown attachment', async () => {
@@ -144,7 +145,7 @@ describe('AttachmentStorage', () => {
         expect(attachmentID).toBeDefined();
         expect(attachment).toEqual({
             attachmentID,
-            source: `/mock/documents/attachments/${attachmentID}.jpg`,
+            source: `/mock/caches/attachments/${attachmentID}.jpg`,
             remoteSource: sourceURL,
         });
     });
@@ -188,7 +189,7 @@ describe('AttachmentStorage', () => {
         expect(attachmentID).toBeDefined();
         expect(attachment).toEqual({
             attachmentID,
-            source: `/mock/documents/attachments/${attachmentID}.jpg`,
+            source: `/mock/caches/attachments/${attachmentID}.jpg`,
             remoteSource: sourceURL,
         });
 
@@ -207,7 +208,7 @@ describe('AttachmentStorage', () => {
         // Then the attachment should be updated with new attachment link
         expect(newAttachment).toEqual({
             attachmentID,
-            source: `/mock/documents/attachments/${attachmentID}.jpg`,
+            source: `/mock/caches/attachments/${attachmentID}.jpg`,
             remoteSource: newSourceURL,
         });
     });
@@ -260,7 +261,7 @@ describe('AttachmentStorage', () => {
         expect(attachmentID).toBeDefined();
         expect(newAttachment).toEqual({
             attachmentID,
-            source: `/mock/documents/attachments/${attachmentID}.jpg`,
+            source: `/mock/caches/attachments/${attachmentID}.jpg`,
             remoteSource: fileData.uri,
         });
 
@@ -323,7 +324,7 @@ describe('AttachmentStorage', () => {
         expect(attachmentID).toBeDefined();
         expect(newAttachment).toEqual({
             attachmentID,
-            source: `/mock/documents/attachments/${attachmentID}.jpg`,
+            source: `/mock/caches/attachments/${attachmentID}.jpg`,
             remoteSource: sourceURL,
         });
 
@@ -409,14 +410,14 @@ describe('AttachmentStorage', () => {
                 expect(remoteSourceIndex).toBeDefined();
                 expect(attachment).toEqual({
                     attachmentID,
-                    source: `/mock/documents/attachments/${attachmentID}.jpg`,
+                    source: `/mock/caches/attachments/${attachmentID}.jpg`,
                     remoteSource: markdownAttachments.at(remoteSourceIndex),
                 });
                 continue;
             }
             expect(attachment).toEqual({
                 attachmentID,
-                source: `/mock/documents/attachments/${attachmentID}.jpg`,
+                source: `/mock/caches/attachments/${attachmentID}.jpg`,
             });
         }