Added GraphQL query function.

src/lib.rs

@@ -5,4 +5,26 @@ impl Database {
     pub fn new() -> Self {
         Self {}
     }
+
+    pub async fn query(&self, _qry: &str) -> String {
+        "{data{}}".to_string()
+    }
+}
+
+#[cfg(test)]
+mod queries {
+    use super::*;
+
+    #[async_std::test]
+    async fn empty_table_query() {
+        let expected = "{data{}}";
+        let testdb = Database::new();
+        let output = testdb.query("{tables{name}}").await;
+        assert!(
+            output == expected,
+            "Got '{}' expected '{}'.",
+            output,
+            expected
+        );
+    }
 }