Add hardlink and symlink support

README.md

@@ -138,6 +138,11 @@ type ManagedFetchResult = {
   - App groups are used on iOS/MacOS for storing content, which is shared between apps.
   - This is e.g. useful for sharing data between your iOS/MacOS app and a widget or a watch app.
 
+`FileSystem.hardlink(source: string, target: string): Promise<void>`
+
+- Create a hard link at target pointing to source.
+  - Note: On Android, creating hardlinks requires root access.
+
 `FilesSystem.hash(path: string, algorithm: 'MD5' | 'SHA-1' | 'SHA-224' | 'SHA-256' | 'SHA-384' | 'SHA-512'): Promise<string>`
 
 - Hash the file content.
@@ -187,6 +192,10 @@ type FileStat = {
 
 - Read metadata of all files in a directory.
 
+`FileSystem.symlink(source: string, target: string): Promise<void>`
+
+- Create a symbolic link at target pointing to source.
+
 `FileSystem.unlink(path: string): Promise<void>`
 
 - Delete a file.

android/src/main/java/com/alpha0010/fs/FileAccessModule.kt

@@ -25,6 +25,7 @@ import java.io.OutputStream
 import java.lang.ref.WeakReference
 import java.security.MessageDigest
 import java.util.zip.ZipInputStream
+import java.nio.file.Files
 
 class FileAccessModule internal constructor(context: ReactApplicationContext) :
   FileAccessSpec(context) {
@@ -275,6 +276,40 @@ class FileAccessModule internal constructor(context: ReactApplicationContext) :
     promise.reject("ERR", "App group unavailable on Android.")
   }
 
+  @ReactMethod
+  override fun hardlink(source: String, target: String, promise: Promise) {
+    ioScope.launch {
+      try {
+        if (source.isContentUri() || target.isContentUri()) {
+          promise.reject("ERR", "Hard links are not supported for content URIs")
+          return@launch
+        }
+
+        val sourceFile = parsePathToFile(source)
+        val targetFile = parsePathToFile(target)
+
+        if (!sourceFile.exists()) {
+          promise.reject("ENOENT", "Source file '$source' does not exist")
+          return@launch
+        }
+
+        if (targetFile.exists()) {
+          promise.reject("EEXIST", "Target file '$target' already exists")
+          return@launch
+        }
+
+        try {
+          Files.createLink(targetFile.toPath(), sourceFile.toPath())
+          promise.resolve(null)
+        } catch (e: IOException) {
+          promise.reject("ERR", "Failed to create hard link: ${e.message}")
+        }
+      } catch (e: Throwable) {
+        promise.reject(e)
+      }
+    }
+  }
+
   @ReactMethod
   override fun hash(path: String, algorithm: String, promise: Promise) {
     ioScope.launch {
@@ -455,6 +490,40 @@ class FileAccessModule internal constructor(context: ReactApplicationContext) :
     }
   }
 
+  @ReactMethod
+  override fun symlink(source: String, target: String, promise: Promise) {
+    ioScope.launch {
+      try {
+        if (source.isContentUri() || target.isContentUri()) {
+          promise.reject("ERR", "Symbolic links are not supported for content URIs")
+          return@launch
+        }
+
+        val sourceFile = parsePathToFile(source)
+        val targetFile = parsePathToFile(target)
+
+        if (!sourceFile.exists()) {
+          promise.reject("ENOENT", "Source file '$source' does not exist")
+          return@launch
+        }
+
+        if (targetFile.exists()) {
+          promise.reject("EEXIST", "Target file '$target' already exists")
+          return@launch
+        }
+
+        try {
+          Files.createSymbolicLink(targetFile.toPath(), sourceFile.toPath())
+          promise.resolve(null)
+        } catch (e: IOException) {
+          promise.reject("ERR", "Failed to create symbolic link: ${e.message}")
+        }
+      } catch (e: Throwable) {
+        promise.reject(e)
+      }
+    }
+  }
+
   @ReactMethod
   override fun unlink(path: String, promise: Promise) {
     ioScope.launch {

android/src/oldarch/FileAccessSpec.kt

@@ -24,6 +24,7 @@ abstract class FileAccessSpec internal constructor(context: ReactApplicationCont
   abstract fun exists(path: String, promise: Promise)
   abstract fun fetch(requestId: Double, resource: String, init: ReadableMap)
   abstract fun getAppGroupDir(groupName: String, promise: Promise)
+  abstract fun hardlink(source: String, target: String, promise: Promise)
   abstract fun hash(path: String, algorithm: String, promise: Promise)
   abstract fun isDir(path: String, promise: Promise)
   abstract fun ls(path: String, promise: Promise)
@@ -33,6 +34,7 @@ abstract class FileAccessSpec internal constructor(context: ReactApplicationCont
   abstract fun readFileChunk(path: String, offset: Double, length: Double, encoding: String, promise: Promise)
   abstract fun stat(path: String, promise: Promise)
   abstract fun statDir(path: String, promise: Promise)
+  abstract fun symlink(source: String, target: String, promise: Promise)
   abstract fun unlink(path: String, promise: Promise)
   abstract fun unzip(source: String, target: String, promise: Promise)
   abstract fun writeFile(path: String, data: String, encoding: String, promise: Promise)

ios/FileAccess.mm

@@ -16,6 +16,7 @@ - (void)df:(RCTPromiseResolveBlock _Nonnull)resolve withRejecter:(RCTPromiseReje
 - (void)exists:(NSString * _Nonnull)path withResolver:(RCTPromiseResolveBlock _Nonnull)resolve withRejecter:(RCTPromiseRejectBlock _Nonnull)reject;
 - (void)fetch:(NSNumber * _Nonnull)requestId withResource:(NSString * _Nonnull)resource withConfig:(NSDictionary * _Nonnull)config withEmitter:(RCTEventEmitter * _Nonnull)emitter;
 - (void)getAppGroupDir:(NSString * _Nonnull)groupName withResolver:(RCTPromiseResolveBlock _Nonnull)resolve withRejecter:(RCTPromiseRejectBlock _Nonnull)reject;
+- (void)hardlink:(NSString * _Nonnull)source withTarget:(NSString * _Nonnull)target withResolver:(RCTPromiseResolveBlock _Nonnull)resolve withRejecter:(RCTPromiseRejectBlock _Nonnull)reject;
 - (void)hash:(NSString * _Nonnull)path withAlgorithm:(NSString * _Nonnull)algorithm withResolver:(RCTPromiseResolveBlock _Nonnull)resolve withRejecter:(RCTPromiseRejectBlock _Nonnull)reject;
 - (void)isDir:(NSString * _Nonnull)path withResolver:(RCTPromiseResolveBlock _Nonnull)resolve withRejecter:(RCTPromiseRejectBlock _Nonnull)reject;
 - (void)ls:(NSString * _Nonnull)path withResolver:(RCTPromiseResolveBlock _Nonnull)resolve withRejecter:(RCTPromiseRejectBlock _Nonnull)reject;
@@ -25,6 +26,7 @@ - (void)readFile:(NSString * _Nonnull)path withEncoding:(NSString * _Nonnull)enc
 - (void)readFileChunk:(NSString * _Nonnull)path withOffset:(NSNumber * _Nonnull)offset withLength:(NSNumber * _Nonnull)length withEncoding:(NSString * _Nonnull)encoding withResolver:(RCTPromiseResolveBlock _Nonnull)resolve withRejecter:(RCTPromiseRejectBlock _Nonnull)reject;
 - (void)stat:(NSString * _Nonnull)path withResolver:(RCTPromiseResolveBlock _Nonnull)resolve withRejecter:(RCTPromiseRejectBlock _Nonnull)reject;
 - (void)statDir:(NSString * _Nonnull)path withResolver:(RCTPromiseResolveBlock _Nonnull)resolve withRejecter:(RCTPromiseRejectBlock _Nonnull)reject;
+- (void)symlink:(NSString * _Nonnull)source withTarget:(NSString * _Nonnull)target withResolver:(RCTPromiseResolveBlock _Nonnull)resolve withRejecter:(RCTPromiseRejectBlock _Nonnull)reject;
 - (void)unlink:(NSString * _Nonnull)path withResolver:(RCTPromiseResolveBlock _Nonnull)resolve withRejecter:(RCTPromiseRejectBlock _Nonnull)reject;
 - (void)unzip:(NSString * _Nonnull)source withTarget:(NSString * _Nonnull)target withResolver:(RCTPromiseResolveBlock _Nonnull)resolve withRejecter:(RCTPromiseRejectBlock _Nonnull)reject;
 - (void)writeFile:(NSString * _Nonnull)path withData:(NSString * _Nonnull)data withEncoding:(NSString * _Nonnull)encoding withResolver:(RCTPromiseResolveBlock _Nonnull)resolve withRejecter:(RCTPromiseRejectBlock _Nonnull)reject;
@@ -126,6 +128,14 @@ - (instancetype)init
     [impl getAppGroupDir:groupName withResolver:resolve withRejecter:reject];
 }
 
+RCT_EXPORT_METHOD(hardlink:(NSString *)source
+                  target:(NSString *)target
+                  resolve:(RCTPromiseResolveBlock)resolve
+                  reject:(RCTPromiseRejectBlock)reject)
+{
+    [impl hardlink:source withTarget:target withResolver:resolve withRejecter:reject];
+}
+
 RCT_EXPORT_METHOD(hash:(NSString *)path
                   algorithm:(NSString *)algorithm
                   resolve:(RCTPromiseResolveBlock)resolve
@@ -198,6 +208,14 @@ - (instancetype)init
     [impl statDir:path withResolver:resolve withRejecter:reject];
 }
 
+RCT_EXPORT_METHOD(symlink:(NSString *)source
+                  target:(NSString *)target
+                  resolve:(RCTPromiseResolveBlock)resolve
+                  reject:(RCTPromiseRejectBlock)reject)
+{
+    [impl symlink:source withTarget:target withResolver:resolve withRejecter:reject];
+}
+
 RCT_EXPORT_METHOD(unlink:(NSString *)path
                   resolve:(RCTPromiseResolveBlock)resolve
                   reject:(RCTPromiseRejectBlock)reject)

ios/FileAccess.swift

@@ -172,6 +172,18 @@ public class FileAccess : NSObject {
         resolve(groupURL.path)
     }
 
+    @objc(hardlink:withTarget:withResolver:withRejecter:)
+    public func hardlink(source: String, target: String, resolve: @escaping RCTPromiseResolveBlock, reject: @escaping RCTPromiseRejectBlock) -> Void {
+        DispatchQueue.global().async {
+            do {
+                try FileManager.default.linkItem(atPath: source.path(), toPath: target.path())
+                resolve(nil)
+            } catch {
+                reject("ERR", "Failed to create hard link from '\(source)' to '\(target)'. \(error.localizedDescription)", error)
+            }
+        }
+    }
+
     @objc(hash:withAlgorithm:withResolver:withRejecter:)
     public func hash(path: String, algorithm: String, resolve: @escaping RCTPromiseResolveBlock, reject: @escaping RCTPromiseRejectBlock) -> Void {
         DispatchQueue.global().async {
@@ -280,10 +292,10 @@ public class FileAccess : NSObject {
                 defer {
                     fileHandle.closeFile()
                 }
-                
+
                 fileHandle.seek(toFileOffset: UInt64(truncating: offset))
                 let binaryData = fileHandle.readData(ofLength: Int(truncating: length))
-                
+
                 if encoding == "base64" {
                     resolve(binaryData.base64EncodedString())
                 } else {
@@ -324,6 +336,18 @@ public class FileAccess : NSObject {
         }
     }
 
+    @objc(symlink:withTarget:withResolver:withRejecter:)
+    public func symlink(source: String, target: String, resolve: @escaping RCTPromiseResolveBlock, reject: @escaping RCTPromiseRejectBlock) -> Void {
+        DispatchQueue.global().async {
+            do {
+                try FileManager.default.createSymbolicLink(atPath: target.path(), withDestinationPath: source.path())
+                resolve(nil)
+            } catch {
+                reject("ERR", "Failed to create symbolic link from '\(source)' to '\(target)'. \(error.localizedDescription)", error)
+            }
+        }
+    }
+
     @objc(unlink:withResolver:withRejecter:)
     public func unlink(path: String, resolve: @escaping RCTPromiseResolveBlock, reject: @escaping RCTPromiseRejectBlock) -> Void {
         DispatchQueue.global().async {

jest/react-native-file-access.ts

@@ -120,6 +120,17 @@ class FileSystemMock {
     return `${Dirs.DocumentDir}/shared/AppGroup/${groupName}`;
   });
 
+  /**
+   * Create a hard link.
+   */
+  public hardlink = jest.fn(async (source: string, target: string) => {
+    const sourceData = this.filesystem.get(source);
+    if (!sourceData) {
+      throw new Error(`Source file ${source} not found`);
+    }
+    this.filesystem.set(target, sourceData);
+  });
+
   /**
    * Hash the file content.
    */
@@ -166,6 +177,17 @@ class FileSystemMock {
     })
   );
 
+  /**
+   * Create a symbolic link.
+   */
+  public symlink = jest.fn(async (source: string, target: string) => {
+    const sourceData = this.filesystem.get(source);
+    if (!sourceData) {
+      throw new Error(`Source file ${source} not found`);
+    }
+    this.filesystem.set(target, sourceData);
+  });
+
   /**
    * Delete a file.
    */

src/NativeFileAccess.ts

@@ -65,6 +65,7 @@ export interface Spec extends TurboModule {
     MainBundleDir: string;
     SDCardDir?: string;
   };
+  hardlink(source: string, target: string): Promise<void>;
   hash(path: string, algorithm: string): Promise<string>;
   isDir(path: string): Promise<boolean>;
   ls(path: string): Promise<string[]>;
@@ -79,6 +80,7 @@ export interface Spec extends TurboModule {
   ): Promise<string>;
   stat(path: string): Promise<FileStat>;
   statDir(path: string): Promise<FileStat[]>;
+  symlink(source: string, target: string): Promise<void>;
   unlink(path: string): Promise<void>;
   unzip(source: string, target: string): Promise<void>;
   writeFile(path: string, data: string, encoding: string): Promise<void>;

src/index.ts

@@ -231,6 +231,15 @@ export const FileSystem = {
     return FileAccessNative.getAppGroupDir(groupName);
   },
 
+  /**
+   * Create a hard link.
+   *
+   * Creates a hard link at target pointing to source.
+   */
+  hardlink(source: string, target: string) {
+    return FileAccessNative.hardlink(source, target);
+  },
+
   /**
    * Hash the file content.
    */
@@ -301,6 +310,15 @@ export const FileSystem = {
     return FileAccessNative.statDir(path);
   },
 
+  /**
+   * Create a symbolic link.
+   *
+   * Creates a symbolic link at target pointing to source.
+   */
+  symlink(source: string, target: string) {
+    return FileAccessNative.symlink(source, target);
+  },
+
   /**
    * Delete a file.
    */