Add a test for empty arrays

Author: LukeMathWalker

src/arrayformat.rs

@@ -231,6 +231,14 @@ mod formatting_with_omit {
         println!("Expected output:\n{}\nActual output:\n{}", expected, actual);
     }
 
+    #[test]
+    fn empty_arrays() {
+        let a: Array2<u32> = arr2(&[[], []]);
+        let actual_output = format!("{}", a);
+        let expected_output = String::from("[[]]");
+        assert_eq!(actual_output, expected_output);
+    }
+
     #[test]
     fn dim_0() {
         let element = 12;