Integration tests for single-line files

tests/examples/single-line.txt

@@ -0,0 +1 @@
+Single Line

tests/integration_tests.rs

@@ -128,6 +128,27 @@ fn concatenate_empty_first_and_last() {
         .stdout("hello world\n");
 }
 
+#[test]
+fn concatenate_single_line() {
+    bat()
+        .arg("single-line.txt")
+        .arg("single-line.txt")
+        .assert()
+        .success()
+        .stdout("Single LineSingle Line");
+}
+
+#[test]
+fn concatenate_single_line_empty() {
+    bat()
+        .arg("single-line.txt")
+        .arg("empty.txt")
+        .arg("single-line.txt")
+        .assert()
+        .success()
+        .stdout("Single LineSingle Line");
+}
+
 #[test]
 fn line_numbers() {
     bat()