new_ret_no_self added test cases

Author: JoshMcguigan

clippy_lints/src/types.rs

@@ -1920,7 +1920,6 @@ enum ImplicitHasherType<'tcx> {
 
 impl<'tcx> ImplicitHasherType<'tcx> {
     /// Checks that `ty` is a target type without a BuildHasher.
-    #[allow(clippy::new_ret_no_self)]
     fn new<'a>(cx: &LateContext<'a, 'tcx>, hir_ty: &hir::Ty) -> Option<Self> {
         if let TyKind::Path(QPath::Resolved(None, ref path)) = hir_ty.node {
             let params: Vec<_> = path.segments.last().as_ref()?.args.as_ref()?

tests/ui/new_ret_no_self.rs

@@ -140,3 +140,24 @@ impl MutPointerReturnerBad {
     // should trigger lint
     pub fn new() -> *mut V { unimplemented!(); }
 }
+
+struct GenericReturnerOk;
+
+impl GenericReturnerOk {
+    // should not trigger lint
+    pub fn new() -> Option<Self> { unimplemented!(); }
+}
+
+struct GenericReturnerBad;
+
+impl GenericReturnerBad {
+    // should trigger lint
+    pub fn new() -> Option<u32> { unimplemented!(); }
+}
+
+struct NestedReturnerOk;
+
+impl NestedReturnerOk {
+    // should trigger lint
+    pub fn new() -> (Option<Self>, u32) { unimplemented!(); }
+}

tests/ui/new_ret_no_self.stderr

@@ -36,5 +36,11 @@ error: methods called `new` usually return `Self`
 141 |     pub fn new() -> *mut V { unimplemented!(); }
     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 5 previous errors
+error: methods called `new` usually return `Self`
+   --> $DIR/new_ret_no_self.rs:155:5
+    |
+155 |     pub fn new() -> Option<u32> { unimplemented!(); }
+    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 6 previous errors