add arbitrary crate as optional dependency

to avoid converting `Input` in fuzz test for making arbitrary inputs

fuzz/fuzz_targets/edit.rs

@@ -4,77 +4,19 @@ use arbitrary::{Arbitrary, Result, Unstructured};
 use libfuzzer_sys::fuzz_target;
 use std::iter;
 use std::str;
-use tui_textarea::{Input, Key, TextArea};
-
-macro_rules! arbitrary_key_enum {
-    ($($p:ident$(($x:ident))?,)+) => {
-
-        #[derive(Arbitrary)]
-        enum ArbitraryKey {
-            $(
-                $p$(($x))?,
-            )+
-        }
-
-        impl From<ArbitraryKey> for Key {
-            fn from(k: ArbitraryKey) -> Key {
-                match k {
-                    $(
-                        ArbitraryKey::$p$(($x))? => Key::$p$(($x))?,
-                    )+
-                }
-            }
-        }
-    }
-}
-
-arbitrary_key_enum!(
-    Char(char),
-    F(u8),
-    Backspace,
-    Enter,
-    Left,
-    Right,
-    Up,
-    Down,
-    Tab,
-    Delete,
-    Home,
-    End,
-    PageUp,
-    PageDown,
-    Esc,
-    Null,
-);
-
-#[derive(Arbitrary)]
-struct ArbitraryInput {
-    key: ArbitraryKey,
-    ctrl: bool,
-    alt: bool,
-}
-
-impl From<ArbitraryInput> for Input {
-    fn from(i: ArbitraryInput) -> Input {
-        Input {
-            key: i.key.into(),
-            ctrl: i.ctrl,
-            alt: i.alt,
-        }
-    }
-}
+use tui_textarea::{Input, TextArea};
 
 fn fuzz(data: &[u8]) -> Result<()> {
     let mut u = Unstructured::new(data);
-    let inputs: Vec<_> = iter::repeat_with(|| ArbitraryInput::arbitrary(&mut u))
-        .take(10)
+    let inputs: Vec<_> = iter::repeat_with(|| Input::arbitrary(&mut u))
+        .take(100)
         .collect::<Result<_>>()?;
     let text = <&str>::arbitrary(&mut u)?;
     let mut textarea = TextArea::from(text.lines());
     for input in inputs {
         textarea.input(input);
+        let _ = textarea.widget();
     }
-    let _ = textarea.widget();
     Ok(())
 }