diff --git a/server/texture-sync-server/src/persistency/search/query_filter.rs b/server/texture-sync-server/src/persistency/search/query_filter.rs
index fae15e4..22bcf98 100644
--- a/server/texture-sync-server/src/persistency/search/query_filter.rs
+++ b/server/texture-sync-server/src/persistency/search/query_filter.rs
@@ -1,6 +1,7 @@
 use crate::model::*;
 use std::str::FromStr;
 
+#[derive(Debug, PartialEq, Eq, Clone)]
 pub enum QueryFilter {
     Not(Box<QueryFilter>),
     Tag(String),
@@ -10,15 +11,19 @@ pub enum QueryFilter {
     SpecialMinResolution(u64),
 }
 
+#[derive(Debug, PartialEq, Eq, Clone)]
 pub enum Score {
     RequiredMatch(bool),
     Match(bool),
 }
 
+#[derive(Debug, PartialEq, Eq, Clone)]
 pub enum QueryFilterSyntaxError {
     UnknownSpecialFilter,
     ResolutionArgumentInvalid,
     DateArgumentInvalid,
+    NameArgumentInvalid,
+    ArgumentInvalid,
 }
 
 use std::ops::Not;
@@ -84,7 +89,9 @@ impl FromStr for QueryFilter {
         const NEGATION_CHAR: char = '!';
         const SPLIT_CHAR: char = ':';
 
-        if input.starts_with(NEGATION_CHAR) {
+        if input.is_empty() {
+            return Err(QueryFilterSyntaxError::ArgumentInvalid);
+        } else if input.starts_with(NEGATION_CHAR) {
             // A Not.
             let inner = Self::from_str(&input[1..])?;
             return Ok(QueryFilter::Not(Box::new(inner)));
@@ -95,7 +102,12 @@ impl FromStr for QueryFilter {
             let filter_arg = parts.next().unwrap();
 
             match filter_name.as_str() {
-                "n" | "name" => Ok(QueryFilter::SpecialInName(filter_name.to_string())),
+                "n" | "name" => {
+                    if filter_arg.is_empty() {
+                        return Err(QueryFilterSyntaxError::NameArgumentInvalid);
+                    }
+                    Ok(QueryFilter::SpecialInName(filter_arg.to_string()))
+                }
                 "r" | "res" | "resolution" => {
                     let num: u64;
 
@@ -133,3 +145,63 @@ impl FromStr for QueryFilter {
         }
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn parsing() {
+        assert!(QueryFilter::from_str("cats:meep").is_err());
+        assert!(QueryFilter::from_str("name:").is_err());
+        assert!(QueryFilter::from_str("res:-400k").is_err());
+        assert!(QueryFilter::from_str("res:4647846846846864864846868446864846844684784k").is_err());
+        assert!(QueryFilter::from_str("!!!!a:80-50-50").is_err());
+
+        assert_eq!(
+            QueryFilter::from_str("n:hello"),
+            Ok(QueryFilter::SpecialInName("hello".to_string()))
+        );
+
+        assert_eq!(
+            QueryFilter::from_str("NaMe:hello"),
+            Ok(QueryFilter::SpecialInName("hello".to_string()))
+        );
+
+        assert_eq!(
+            QueryFilter::from_str("res:4k"),
+            Ok(QueryFilter::SpecialMinResolution(4096))
+        );
+
+        assert_eq!(
+            QueryFilter::from_str("res:4096"),
+            Ok(QueryFilter::SpecialMinResolution(4096))
+        );
+
+        assert_eq!(
+            QueryFilter::from_str("a:2019-10-10"),
+            Ok(QueryFilter::SpecialAfterDate(Date::new(2019, 10, 10)))
+        );
+
+        assert_eq!(
+            QueryFilter::from_str("!before:2019-10-10"),
+            Ok(QueryFilter::Not(
+                QueryFilter::SpecialBeforeDate(Date::new(2019, 10, 10)).into()
+            ))
+        );
+
+        assert_eq!(
+            QueryFilter::from_str("!before:2019-10-10"),
+            Ok(QueryFilter::Not(
+                QueryFilter::SpecialBeforeDate(Date::new(2019, 10, 10)).into()
+            ))
+        );
+
+        assert_eq!(
+            QueryFilter::from_str("!Wood"),
+            Ok(QueryFilter::Not(
+                QueryFilter::Tag("Wood".to_string()).into()
+            ))
+        );
+    }
+}