Fix linting problems

Author: b-NC

CHANGELOG.md

@@ -3273,7 +3273,6 @@ Released 2018-09-13
 [`exhaustive_enums`]: https://rust-lang.github.io/rust-clippy/master/index.html#exhaustive_enums
 [`exhaustive_structs`]: https://rust-lang.github.io/rust-clippy/master/index.html#exhaustive_structs
 [`exit`]: https://rust-lang.github.io/rust-clippy/master/index.html#exit
-[`expect_err`]: https://rust-lang.github.io/rust-clippy/master/index.html#expect_err
 [`expect_fun_call`]: https://rust-lang.github.io/rust-clippy/master/index.html#expect_fun_call
 [`expect_used`]: https://rust-lang.github.io/rust-clippy/master/index.html#expect_used
 [`expl_impl_clone_on_copy`]: https://rust-lang.github.io/rust-clippy/master/index.html#expl_impl_clone_on_copy

clippy_lints/src/methods/expect_err.rs

@@ -4,11 +4,14 @@ use rustc_lint::LateContext;
 use rustc_span::sym;
 
 pub(super) fn check(cx: &LateContext<'_>, expr: &rustc_hir::Expr<'_>, recv: &rustc_hir::Expr<'_>) {
-    if_chain! {
-        if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(recv), sym::Result);
-
-        then {
-            span_lint_and_help(cx, EXPECT_ERR, expr.span, "Called `.err().expect()` on a `Result` value", None, "`.expect_err()` can be called instead")
-        }
+    if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(recv), sym::Result) {
+        span_lint_and_help(
+            cx,
+            EXPECT_ERR,
+            expr.span,
+            "called `.err().expect()` on a `Result` value",
+            None,
+            "`.expect_err()` can be called instead",
+        );
     }
 }

clippy_lints/src/methods/mod.rs

@@ -371,13 +371,13 @@ declare_clippy_lint! {
     /// Because .expect_err() can be called directly.
     ///
     /// ### Example
-    /// ```rust
+    /// ```should_panic
     /// // example code where clippy issues a warning
     /// let x: Result<u32, &str> = Ok(10);
     /// x.err().expect("Testing err().expect()");
     /// ```
     /// Use instead:
-    /// ```rust
+    /// ```should_panic
     /// // example code which does not raise clippy warning
     /// let x: Result<u32, &str> = Ok(10);
     /// x.expect_err("Testing expect_err");
@@ -2191,6 +2191,7 @@ impl_lint_pass!(Methods => [
     NEEDLESS_SPLITN,
     UNNECESSARY_TO_OWNED,
     UNNECESSARY_JOIN,
+    EXPECT_ERR,
 ]);
 
 /// Extracts a method call name, args, and `Span` of the method name.

tests/ui/expect_err.stderr

@@ -1,4 +1,4 @@
-error: Called `.err().expect()` on a `Result` value
+error: called `.err().expect()` on a `Result` value
   --> $DIR/expect_err.rs:3:5
    |
 LL |     x.err().expect("Testing expect_err");