add insert_delete fuzzing target

CONTRIBUTING.md

@@ -72,6 +72,10 @@ tail -F debug.txt
 To run fuzzing tests, [cargo-fuzz][] and Rust nightly toolchain are necessary.
 
 ```sh
+# Show list of fuzzing targets
+cargo +nightly fuzz list
+
+# Run 'edit' fuzzing test case
 cargo +nightly fuzz run edit
 ```
 

fuzz/Cargo.lock

@@ -363,7 +363,7 @@ dependencies = [
 
 [[package]]
 name = "tui-textarea"
-version = "0.2.4"
+version = "0.3.0"
 dependencies = [
  "arbitrary",
  "crossterm",

fuzz/Cargo.toml

@@ -23,3 +23,9 @@ name = "edit"
 path = "fuzz_targets/edit.rs"
 test = false
 doc = false
+
+[[bin]]
+name = "insert_delete"
+path = "fuzz_targets/insert_delete.rs"
+test = false
+doc = false

fuzz/fuzz_targets/insert_delete.rs

@@ -0,0 +1,26 @@
+#![no_main]
+
+use arbitrary::{Arbitrary as _, Result, Unstructured};
+use libfuzzer_sys::fuzz_target;
+use tui_textarea::{CursorMove, TextArea};
+use tui_textarea_bench::{dummy_terminal, TerminalExt};
+
+fn fuzz(data: &[u8]) -> Result<()> {
+    let mut term = dummy_terminal();
+    let mut textarea = TextArea::default();
+    let mut data = Unstructured::new(data);
+    for i in 0..100 {
+        textarea.move_cursor(CursorMove::arbitrary(&mut data)?);
+        if i % 2 == 0 {
+            textarea.insert_str(String::arbitrary(&mut data)?);
+        } else {
+            textarea.delete_str(usize::arbitrary(&mut data)?);
+        }
+        term.draw_textarea(&mut textarea);
+    }
+    Ok(())
+}
+
+fuzz_target!(|data: &[u8]| {
+    fuzz(data).unwrap();
+});