Add arrays to all helpers tests.

src/bin.rs

@@ -212,6 +212,7 @@ impl CompareContextElement for serde_json::Value {
                         serde_json::Value::String(self_string),
                         serde_json::Value::String(other_string),
                     ) => self_string.partial_cmp(other_string),
+                    // TODO: Non-scalar types
                     _ => None,
                 };
             }