Add test for {:#?} format of Value

tests/debug.rs

@@ -49,3 +49,24 @@ fn error() {
     let expected = "Error(\"key must be a string\", line: 1, column: 2)";
     assert_eq!(format!("{:?}", err), expected);
 }
+
+const INDENTED_EXPECTED: &str = r#"Object(
+    {
+        "array": Array(
+            [
+                Number(
+                    0,
+                ),
+                Number(
+                    1,
+                ),
+            ],
+        ),
+    },
+)"#;
+
+#[test]
+fn indented() {
+    let j = json!({ "array": [0, 1] });
+    assert_eq!(format!("{:#?}", j), INDENTED_EXPECTED);
+}