fixed test

clippy_lints/src/methods/append_instead_of_extend.rs

@@ -16,10 +16,10 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, recv: &Expr<'_>, arg:
         //check source object
         if let ExprKind::MethodCall(src_method, _, [drain_vec, drain_arg], _) = &arg.kind;
         if src_method.ident.as_str() == "drain";
-        let src_ty = cx.typeck_results().expr_ty(&drain_vec).peel_refs();
+        let src_ty = cx.typeck_results().expr_ty(drain_vec).peel_refs();
         if is_type_diagnostic_item(cx, src_ty, sym::vec_type);
         //check drain range
-        let src_ty_range = cx.typeck_results().expr_ty(&drain_arg).peel_refs();
+        let src_ty_range = cx.typeck_results().expr_ty(drain_arg).peel_refs();
         if is_type_lang_item(cx, src_ty_range, LangItem::RangeFull);
         let mut applicability = Applicability::MachineApplicable;
         then {

clippy_lints/src/methods/mod.rs

@@ -1057,7 +1057,7 @@ declare_clippy_lint! {
 declare_clippy_lint! {
     /// **What it does:** Checks for occurrences where one vector gets extended instead of append
     ///
-    /// **Why is this bad?** Using `append` instead of `extend` is more precise and faster
+    /// **Why is this bad?** Using `append` instead of `extend` is more concise and faster
     ///
     /// **Known problems:** None.
     ///
@@ -1075,7 +1075,7 @@ declare_clippy_lint! {
     /// ```
     pub APPEND_INSTEAD_OF_EXTEND,
     perf,
-    "default lint description"
+    "using vec.append(&mut vec) to move the full range of a vecor to another"
 }
 
 declare_clippy_lint! {

tests/ui/append_instead_of_extend.fixed

@@ -13,6 +13,11 @@ fn main() {
 
     vec4.append(&mut vec3);
 
+    let mut vec10 = return_vector();
+    let mut vec11: std::vec::Vec<u8> = Vec::new();
+
+    vec11.append(&mut vec10);
+
     //won't get linted it dosen't move the entire content of a vec into another
     let mut test1 = vec![0u8, 10];
     let mut test2: std::vec::Vec<u8> = Vec::new();
@@ -24,16 +29,29 @@ fn main() {
 
     vec3.append(&mut vec7);
 
-
-
     let mut vec5 = vec![0u8; 1024];
     let mut vec6: std::vec::Vec<u8> = Vec::new();
 
     vec5.extend(vec6.drain(..4));
 
+    let mut vec8 = return_vector();
+    let mut vec9: std::vec::Vec<u8> = Vec::new();
+
+    vec8.append(&mut vec9);
+
     //won't get linted because it is not a vec
 
     let mut heap = BinaryHeap::from(vec![1, 3]);
     let mut heap2 = BinaryHeap::from(vec![]);
     heap2.extend(heap.drain())
 }
+
+fn return_vector() -> Vec<u8> {
+    let mut new_vector = vec![];
+
+    for i in 1..10 {
+        new_vector.push(i)
+    }
+
+    new_vector
+}

tests/ui/append_instead_of_extend.rs

@@ -13,6 +13,11 @@ fn main() {
 
     vec4.extend(vec3.drain(..));
 
+    let mut vec10 = return_vector();
+    let mut vec11: std::vec::Vec<u8> = Vec::new();
+
+    vec11.extend(vec10.drain(..));
+
     //won't get linted it dosen't move the entire content of a vec into another
     let mut test1 = vec![0u8, 10];
     let mut test2: std::vec::Vec<u8> = Vec::new();
@@ -24,16 +29,29 @@ fn main() {
 
     vec3.append(&mut vec7);
 
-
-
     let mut vec5 = vec![0u8; 1024];
     let mut vec6: std::vec::Vec<u8> = Vec::new();
 
     vec5.extend(vec6.drain(..4));
 
+    let mut vec8 = return_vector();
+    let mut vec9: std::vec::Vec<u8> = Vec::new();
+
+    vec8.append(&mut vec9);
+
     //won't get linted because it is not a vec
 
     let mut heap = BinaryHeap::from(vec![1, 3]);
     let mut heap2 = BinaryHeap::from(vec![]);
     heap2.extend(heap.drain())
 }
+
+fn return_vector() -> Vec<u8> {
+    let mut new_vector = vec![];
+
+    for i in 1..10 {
+        new_vector.push(i)
+    }
+
+    new_vector
+}

tests/ui/append_instead_of_extend.stderr

@@ -12,5 +12,11 @@ error: use of `extend` instead of `append` for adding the full range of a second
 LL |     vec4.extend(vec3.drain(..));
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `vec4.append(&mut vec3)`
 
-error: aborting due to 2 previous errors
+error: use of `extend` instead of `append` for adding the full range of a second vector
+  --> $DIR/append_instead_of_extend.rs:19:5
+   |
+LL |     vec11.extend(vec10.drain(..));
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `vec11.append(&mut vec10)`
+
+error: aborting due to 3 previous errors