Добавлен флаг --snapshot для команды diff для просмотра изменений в конкретном снимке

source/app.d

@@ -39,7 +39,15 @@ int main(string[] args)
 			)
 		)
 		.add(new Command("status", "Checking the status of tracked files"))
-		.add(new Command("diff", "Show changed data"))
+		.add(new Command("diff", "Show changed data")
+			.add(new Option("s", "snapshot", "Specify snapshot hash")
+				.optional
+				.validateEachWith(
+					opt => opt.isValidHash,
+					"must contain snapshot hash provided"
+				)
+			)
+		)
 		.add(new Command("size", "Size of snapshots"))
 		.add(new Command("import", "Import snapshot from a tar.gz archive")
 			.add(new Argument("archive", "The path to the tar.gz archive file").required)
@@ -167,7 +175,9 @@ int main(string[] args)
 				snag.initialize(init.flag("force"))
 			)
 			.on("diff", diff =>
-				snag.diff()
+				snag.diff(
+					diff.option("snapshot", "")
+				)
 			)
 			.on("size", size =>
 				snag.size()