refactor<*>: rewrite all codes...

src/Commands/IsBinaryFile.cs

@@ -0,0 +1,18 @@
+using System.Text.RegularExpressions;
+
+namespace SourceGit.Commands {
+    /// <summary>
+    ///     查询指定版本下的某文件是否是二进制文件
+    /// </summary>
+    public class IsBinaryFile : Command {
+        private static readonly Regex REG_TEST = new Regex(@"^\-\s+\-\s+.*$");
+        public IsBinaryFile(string repo, string commit, string path) {
+            Cwd = repo;
+            Args = $"diff 4b825dc642cb6eb9a060e54bf8d69288fbee4904 {commit} --numstat -- \"{path}\"";
+        }
+
+        public bool Result() {
+            return REG_TEST.IsMatch(ReadToEnd().Output);
+        }
+    }
+}