finished unit tests and docstrings

MalwareMultiScan.Backends/Interfaces/IScanBackend.cs

@@ -5,11 +5,38 @@ using System.Threading.Tasks;
 
 namespace MalwareMultiScan.Backends.Interfaces
 {
+    /// <summary>
+    /// Scan backend.
+    /// </summary>
     public interface IScanBackend
     {
+        /// <summary>
+        /// Unique backend id.
+        /// </summary>
         public string Id { get; }
+        
+        /// <summary>
+        /// Scan file.
+        /// </summary>
+        /// <param name="path">File path.</param>
+        /// <param name="cancellationToken">Cancellation token.</param>
+        /// <returns>List of detected threats.</returns>
         public Task<string[]> ScanAsync(string path, CancellationToken cancellationToken);
+        
+        /// <summary>
+        /// Scan URL.
+        /// </summary>
+        /// <param name="uri">URL.</param>
+        /// <param name="cancellationToken">Cancellation token.</param>
+        /// <returns>List of detected threats.</returns>
         public Task<string[]> ScanAsync(Uri uri, CancellationToken cancellationToken);
+        
+        /// <summary>
+        /// Scan stream.
+        /// </summary>
+        /// <param name="stream">Stream.</param>
+        /// <param name="cancellationToken">Cancellation token.</param>
+        /// <returns>List of detected threats.</returns>
         public Task<string[]> ScanAsync(Stream stream, CancellationToken cancellationToken);
     }
 }