1 files changed, 37 insertions, 0 deletions

diff --git a/crates/ide_assists/src/handlers/remove_mut.rs b/crates/ide_assists/src/handlers/remove_mut.rs
new file mode 100644
index 000000000..30d36dacd
--- /dev/null
+++ b/crates/ide_assists/src/handlers/remove_mut.rs
@@ -0,0 +1,37 @@
+use syntax::{SyntaxKind, TextRange, T};
+
+use crate::{AssistContext, AssistId, AssistKind, Assists};
+
+// Assist: remove_mut
+//
+// Removes the `mut` keyword.
+//
+// ```
+// impl Walrus {
+//     fn feed(&mut$0 self, amount: u32) {}
+// }
+// ```
+// ->
+// ```
+// impl Walrus {
+//     fn feed(&self, amount: u32) {}
+// }
+// ```
+pub(crate) fn remove_mut(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
+    let mut_token = ctx.find_token_syntax_at_offset(T![mut])?;
+    let delete_from = mut_token.text_range().start();
+    let delete_to = match mut_token.next_token() {
+        Some(it) if it.kind() == SyntaxKind::WHITESPACE => it.text_range().end(),
+        _ => mut_token.text_range().end(),
+    };
+
+    let target = mut_token.text_range();
+    acc.add(
+        AssistId("remove_mut", AssistKind::Refactor),
+        "Remove `mut` keyword",
+        target,
+        |builder| {
+            builder.delete(TextRange::new(delete_from, delete_to));
+        },
+    )
+}