1 files changed, 4 insertions, 1 deletions
diff --git a/src/lib.rs b/src/lib.rs
index a4fa227..a19cbfa 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -17,6 +17,10 @@ extern {
 
 #[wasm_bindgen]
 pub fn generate(len: usize, lower: bool, upper: bool, number: bool, special: bool) -> String {
+    if len == 0 ||!lower && !upper && !number && !special  {
+        return "".to_string();
+    }
+
     let mut upper_charset: Vec<char> = String::from("ABCDEFGHIJKLMNOPQRSTUVWXYZ").chars().collect();
     let mut lower_charset: Vec<char> = String::from("abcdefghijklmnopqrstuvwxyz").chars().collect();
     let mut number_charset: Vec<char> = String::from("1234567890").chars().collect();
@@ -41,7 +45,6 @@ pub fn generate(len: usize, lower: bool, upper: bool, number: bool, special: boo
         result.append(&mut special_charset);
     }
 
-
     (0..len)
         .map(|_| {
             let idx = rng.gen_range(0..result.len());