New type replacement HttpResponse actix

NEWS.md

@@ -1,5 +1,9 @@
 # cargo-mutants changelog
 
+## Unreleased
+
+- Generate `HttpResponse::Ok().finish()` as a mutation of an Actix `HttpResponse`.
+
 ## 23.6.0
 
 - Generate `Box::leak(Box::new(...))` as a mutation of functions returning

book/src/mutants.md

@@ -32,6 +32,7 @@ More mutation genres and patterns will be added in future releases.
 | `Arc<T>`          | `Arc::new(...)`                                            |
 | `[T; L]`          | `[r; L]` for all replacements of T                         |
 | `&T`              | `&...` (all replacements for T)                            |
+| `HttpResponse`    | `HttpResponse::Ok().finish`                                |
 | (any other)       | `Default::default()`                                       |
 
 `...` in the mutation patterns indicates that the type is recursively mutated.

src/visit.rs

@@ -360,6 +360,8 @@ fn type_replacements(type_: &Type, error_exprs: &[Expr]) -> Vec<TokenStream> {
                 reps.extend(error_exprs.iter().map(|error_expr| {
                     quote! { Err(#error_expr) }
                 }));
+            } else if path_ends_with(path, "HttpResponse") {
+                reps.push(quote! { HttpResponse::Ok().finish() });
             } else if let Some(boxed_type) = match_first_type_arg(path, "Box") {
                 reps.extend(
                     type_replacements(boxed_type, error_exprs)
@@ -801,6 +803,14 @@ mod test {
         );
     }
 
+    #[test]
+    fn http_response_replacement() {
+        assert_eq!(
+            replace(&parse_quote! { -> HttpResponse }, &[]),
+            &["HttpResponse::Ok().finish()"]
+        );
+    }
+
     #[test]
     fn option_usize_replacement() {
         let reps = return_type_replacements(&parse_quote! { -> Option<usize> }, &[]);