update error message, refactor disallowed_method

Author: Frank

clippy_lints/src/disallowed_method.rs

@@ -27,7 +27,7 @@ declare_clippy_lint! {
     /// ```
     pub DISALLOWED_METHOD,
     nursery,
-    "used disallowed method call"
+    "use of a disallowed method call"
 }
 
 #[derive(Clone, Debug)]
@@ -55,18 +55,17 @@ impl<'tcx> LateLintPass<'tcx> for DisallowedMethod {
 
             let method_call = cx.get_def_path(def_id);
             if self.disallowed.contains(&method_call) {
+                let method = method_call
+                    .iter()
+                    .map(|s| s.to_ident_string())
+                    .collect::<Vec<_>>()
+                    .join("::");
+
                 span_lint(
                     cx,
                     DISALLOWED_METHOD,
                     expr.span,
-                    &format!(
-                        "Use of a disallowed method `{}`",
-                        method_call
-                            .iter()
-                            .map(|s| s.to_ident_string())
-                            .collect::<Vec<_>>()
-                            .join("::"),
-                    ),
+                    &format!("use of a disallowed method `{}`", method),
                 );
             }
         }

tests/ui-toml/toml_disallowed_method/conf_disallowed_method.stderr

@@ -1,12 +1,12 @@
-error: Use of a disallowed method `regex::re_unicode::Regex::is_match`
+error: use of a disallowed method `regex::re_unicode::Regex::is_match`
   --> $DIR/conf_disallowed_method.rs:10:5
    |
 LL |     re.is_match("abc");
    |     ^^^^^^^^^^^^^^^^^^
    |
    = note: `-D clippy::disallowed-method` implied by `-D warnings`
 
-error: Use of a disallowed method `core::iter::traits::iterator::Iterator::sum`
+error: use of a disallowed method `core::iter::traits::iterator::Iterator::sum`
   --> $DIR/conf_disallowed_method.rs:12:5
    |
 LL |     a.iter().sum::<i32>();

tests/ui/disallowed_method.stderr

@@ -1,18 +1,18 @@
-error: Use of a disallowed method `disallowed_method::Baz::bad_method`
+error: use of a disallowed method `disallowed_method::Baz::bad_method`
   --> $DIR/disallowed_method.rs:48:5
    |
 LL |     b.bad_method();
    |     ^^^^^^^^^^^^^^
    |
    = note: `-D clippy::disallowed-method` implied by `-D warnings`
 
-error: Use of a disallowed method `disallowed_method::Baz::bad_method`
+error: use of a disallowed method `disallowed_method::Baz::bad_method`
   --> $DIR/disallowed_method.rs:49:5
    |
 LL |     c.bad_method();
    |     ^^^^^^^^^^^^^^
 
-error: Use of a disallowed method `disallowed_method::Foo::bad_method`
+error: use of a disallowed method `disallowed_method::Foo::bad_method`
   --> $DIR/disallowed_method.rs:50:5
    |
 LL |     f.bad_method();