Check parsing is inverse to display

1 files changed, 24 insertions, 0 deletions

diff --git a/rust/src/parser.rs b/rust/src/parser.rs
index b3d76fb..812444d 100644
--- a/rust/src/parser.rs
+++ b/rust/src/parser.rs
@@ -37,6 +37,7 @@ fn parse_number(token: &str) -> Result<Value, String> {
 
 #[cfg(test)]
 mod tests {
+    use super::Value;
     use super::Value::*;
     use super::{parse, tokenize};
     use proptest::prelude::*;
@@ -71,4 +72,27 @@ mod tests {
     fn tokenize_several_values() {
         assert_eq!(vec!["42", "foo", "true"], tokenize("42 foo    \ntrue  "));
     }
+
+    impl Arbitrary for Value {
+        type Parameters = ();
+        type Strategy = BoxedStrategy<Self>;
+
+        fn arbitrary_with(_args: ()) -> Self::Strategy {
+            prop_oneof![
+                any::<i32>().prop_map(Num),
+                any::<bool>().prop_map(Bool),
+                // see https://unicode.org/reports/tr18/#General_Category_Property for one letter unicode categories
+                "\\pL(\\pL|\\pN)*".prop_map(Sym),
+            ]
+            .boxed()
+        }
+    }
+
+    proptest! {
+            #[test]
+            fn parse_is_inverse_to_display(values in any::<Vec<Value>>()) {
+                let result : Vec<String> = values.iter().map(|v:&Value| v.to_string()).collect();
+                assert_eq!(values, result.iter().map(|s| parse(s)).collect::<Vec<Value>>());
+            }
+    }
 }