allow LenientError to be serializable too

query-grammar/src/infallible.rs

@@ -1,7 +1,7 @@
 //! nom combinators for infallible operations
 
 use std::convert::Infallible;
-
+use serde::Serialize;
 use nom::{AsChar, IResult, InputLength, InputTakeAtPosition};
 
 pub(crate) type ErrorList = Vec<LenientErrorInternal>;
@@ -15,7 +15,7 @@ pub(crate) struct LenientErrorInternal {
 }
 
 /// A recoverable error and the position it happened at
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Serialize)]
 pub struct LenientError {
     pub pos: usize,
     pub message: String,

query-grammar/src/lib.rs

@@ -47,5 +47,7 @@ mod tests {
     fn test_parse_query_lenient_wrong_query() {
         let (_, errors) = parse_query_lenient("title:");
         assert!(errors.len() == 1);
+        let json = serde_json::to_string(&errors).unwrap();
+        assert_eq!(json, r#"[{"pos":6,"message":"expected word"}]"#);
     }
 }