test: Add Dn type tests

src/dn.rs

@@ -24,6 +24,10 @@ impl Dn {
     pub fn from_dn_str(input: &str) -> Result<Self, LdapError> {
         let mut keys: IndexMap<String, Vec<String>> = IndexMap::new();
 
+        if input == "" {
+            return Ok(Self { keys });
+        }
+
         for query in input.split(',') {
             let mut query_parts = query.split('=');
             // Here we have key=val pairs
@@ -98,3 +102,37 @@ impl Dn {
         self.keys.insert("dc".to_string(), domain_components);
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_basic_dn_str() {
+        let s = "cn=admin,ou=people,dc=example,dc=com";
+        let mut dn = Dn::from_dn_str(s).unwrap();
+
+        assert_eq!(&dn.to_dn_string(), s);
+        assert_eq!(dn.get_hostname().as_deref(), Some("example.com"));
+        dn.set_hostname("a.localhost", false);
+        assert_eq!(dn.get_hostname().as_deref(), Some("a.localhost"));
+        assert_eq!(&dn.to_dn_string(), "cn=admin,ou=people,dc=a,dc=localhost");
+    }
+
+    #[test]
+    fn test_empty_dn_str() {
+        let s = "";
+        let mut dn = Dn::from_dn_str(s).unwrap();
+
+        assert_eq!(&dn.to_dn_string(), s);
+        assert!(dn.get_hostname().is_none());
+
+        dn.set_hostname("a.localhost", false);
+        assert_eq!(dn.get_hostname().as_deref(), None);
+        assert_eq!(&dn.to_dn_string(), s);
+
+        dn.set_hostname("a.localhost", true);
+        assert_eq!(dn.get_hostname().as_deref(), Some("a.localhost"));
+        assert_eq!(&dn.to_dn_string(), "dc=a,dc=localhost");
+    }
+}