feat: Added async extensions to IFileInfo (#66)

* Added all async calls from IFile
* Added EnumerateLinesAsync

Author: gigi81

src/System.IO.Abstractions.Extensions/IFileInfoAsyncExtensions.cs

@@ -0,0 +1,98 @@
+#if NETSTANDARD2_1_OR_GREATER || NET6_0_OR_GREATER
+#nullable enable
+
+using System.Collections.Generic;
+using System.Runtime.CompilerServices;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace System.IO.Abstractions
+{
+    public static class FileInfoFileAsyncExtensions
+    {
+        /// <inheritdoc cref="IFile.AppendAllLinesAsync(string,System.Collections.Generic.IEnumerable{string},System.Threading.CancellationToken)"/>
+        public static async Task AppendAllLinesAsync(this IFileInfo file, IEnumerable<string> contents, CancellationToken cancellationToken = default)
+        {
+            await file.FileSystem.File.AppendAllLinesAsync(file.FullName, contents, cancellationToken);
+        }
+        
+        /// <inheritdoc cref="IFile.AppendAllTextAsync(string,string?,System.Threading.CancellationToken)"/>
+        public static async Task AppendAllTextAsync(this IFileInfo file, string? contents, CancellationToken cancellationToken = default)
+        {
+            await file.FileSystem.File.AppendAllTextAsync(file.FullName, contents, cancellationToken);
+        }
+
+        /// <inheritdoc cref="IFile.ReadAllBytesAsync(string,System.Threading.CancellationToken)"/>
+        public static async Task<byte[]> ReadAllBytesAsync(this IFileInfo file, CancellationToken cancellationToken = default)
+        {
+            return await file.FileSystem.File.ReadAllBytesAsync(file.FullName, cancellationToken);
+        }
+
+        /// <inheritdoc cref="IFile.ReadAllLinesAsync(string,System.Threading.CancellationToken)"/>
+        public static async Task<string[]> ReadAllLinesAsync(this IFileInfo file, CancellationToken cancellationToken = default)
+        {
+            return await file.FileSystem.File.ReadAllLinesAsync(file.FullName, cancellationToken);
+        }
+        
+        /// <inheritdoc cref="IFile.ReadAllTextAsync(string,System.Threading.CancellationToken)" />
+        public static async Task<string> ReadAllTextAsync(this IFileInfo file, CancellationToken cancellationToken = default)
+        {
+            return await file.FileSystem.File.ReadAllTextAsync(file.FullName, cancellationToken);
+        }
+        
+        /// <inheritdoc cref="IFile.WriteAllBytesAsync(string,byte[],System.Threading.CancellationToken)" />
+        public static async Task WriteAllBytesAsync(this IFileInfo file, byte[] bytes, CancellationToken cancellationToken = default)
+        {
+            await file.FileSystem.File.WriteAllBytesAsync(file.FullName, bytes, cancellationToken);
+        }
+
+        /// <inheritdoc cref="IFile.WriteAllLinesAsync(string,System.Collections.Generic.IEnumerable{string},System.Threading.CancellationToken)" />
+        public static async Task WriteAllLinesAsync(this IFileInfo file, IEnumerable<string> contents, CancellationToken cancellationToken = default)
+        {
+            await file.FileSystem.File.WriteAllLinesAsync(file.FullName, contents, cancellationToken);
+        }
+
+        /// <inheritdoc cref="IFile.WriteAllTextAsync(string,string?,System.Threading.CancellationToken)" />
+        public static async Task WriteAllTextAsync(this IFileInfo file, string? contents, CancellationToken cancellationToken = default)
+        {
+            await file.FileSystem.File.WriteAllTextAsync(file.FullName, contents, cancellationToken);
+        }
+
+        /// <summary>
+        /// Creates an <see cref="IAsyncEnumerable{String}"/> that can enumerate asynchronously the lines of text in the specified <paramref name="file"/>
+        /// </summary>
+        /// <param name="file">File to enumerate content</param>
+        /// <param name="cancellationToken"></param>
+        /// <returns>Returns an <see cref="IAsyncEnumerable{String}"/> to enumerate the content of the file</returns>
+        public static IAsyncEnumerable<string> EnumerateLinesAsync(this IFileInfo file, CancellationToken cancellationToken)
+        {
+            return EnumerateLinesAsync(file, null, cancellationToken);
+        }
+
+        /// <summary>
+        /// Creates an <see cref="IAsyncEnumerable{String}"/> that can enumerate asynchronously the lines of text in the specified <paramref name="file"/>
+        /// using the specified <paramref name="encoding"/>
+        /// </summary>
+        /// <param name="file">File to enumerate content</param>
+        /// <param name="encoding">Encoding to use to read the file</param>
+        /// <param name="cancellationToken"></param>
+        /// <returns>Returns an <see cref="IAsyncEnumerable{String}"/> to enumerate the content of the file</returns>
+        public static async IAsyncEnumerable<string> EnumerateLinesAsync(this IFileInfo file, Encoding? encoding, [EnumeratorCancellation] CancellationToken cancellationToken)
+        {
+            await using var stream = file.OpenRead();
+            using var reader = encoding == null
+                ? new StreamReader(stream)
+                : new StreamReader(stream, encoding);
+
+            var line = await reader.ReadLineAsync();
+            while (line != null)
+            {
+                yield return line;
+                cancellationToken.ThrowIfCancellationRequested();                
+                line = await reader.ReadLineAsync();
+            }
+        }
+    }
+}
+#endif

src/System.IO.Abstractions.Extensions/IFileInfoExtensions.cs

@@ -31,6 +31,7 @@ public static IEnumerable<string> EnumerateLines(this IFileInfo file)
         /// using the specified <paramref name="encoding"/>
         /// </summary>
         /// <param name="file">File to enumerate content</param>
+        /// <param name="encoding">Encoding to use to read the file</param>
         /// <returns>Returns an <see cref="IEnumerable{String}"/> to enumerate the content of the file</returns>
         public static IEnumerable<string> EnumerateLines(this IFileInfo file, Encoding encoding)
         {