Implement Display trait for DidDocument (print as json)

Signed-off-by: Patrik Stas <[email protected]>

did_doc/src/schema/did_doc.rs

@@ -1,4 +1,4 @@
-use std::collections::HashMap;
+use std::{collections::HashMap, fmt::Display};
 
 use did_parser::{Did, DidUrl};
 use serde::{Deserialize, Serialize};
@@ -42,6 +42,13 @@ pub struct DidDocument<E> {
     extra: HashMap<String, Value>,
 }
 
+impl Display for DidDocument<()> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let json = serde_json::to_string(self).unwrap();
+        write!(f, "{}", json)
+    }
+}
+
 impl<E> DidDocument<E> {
     pub fn builder(id: Did) -> DidDocumentBuilder<E> {
         DidDocumentBuilder::new(id)

did_doc/src/schema/service.rs

@@ -170,10 +170,7 @@ mod tests {
         .add_service_type(service_type.clone())
         .unwrap()
         .add_service_type(service_type.clone())
-        .unwrap()
-        .build();
-
-        assert_eq!(service.service_type(), &OneOrList::One(service_type));
+        .unwrap_err();
     }
 
     #[test]