Merge remote-tracking branch 'upstream/master' into rustup

clippy_lints/src/methods/mod.rs

@@ -72,6 +72,7 @@ mod or_fun_call;
 mod or_then_unwrap;
 mod path_buf_push_overwrite;
 mod range_zip_with_len;
+mod read_line_without_trim;
 mod repeat_once;
 mod search_is_some;
 mod seek_from_current;
@@ -88,6 +89,7 @@ mod suspicious_command_arg_space;
 mod suspicious_map;
 mod suspicious_splitn;
 mod suspicious_to_owned;
+mod type_id_on_box;
 mod uninit_assumed_init;
 mod unit_hash;
 mod unnecessary_filter_map;
@@ -2925,6 +2927,37 @@ declare_clippy_lint! {
     "use of sort() when sort_unstable() is equivalent"
 }
 
+declare_clippy_lint! {
+    /// ### What it does
+    /// Looks for calls to `<Box<dyn Any> as Any>::type_id`.
+    ///
+    /// ### Why is this bad?
+    /// This most certainly does not do what the user expects and is very easy to miss.
+    /// Calling `type_id` on a `Box<dyn Any>` calls `type_id` on the `Box<..>` itself,
+    /// so this will return the `TypeId` of the `Box<dyn Any>` type (not the type id
+    /// of the value referenced by the box!).
+    ///
+    /// ### Example
+    /// ```rust,ignore
+    /// use std::any::{Any, TypeId};
+    ///
+    /// let any_box: Box<dyn Any> = Box::new(42_i32);
+    /// assert_eq!(any_box.type_id(), TypeId::of::<i32>()); // ⚠️ this fails!
+    /// ```
+    /// Use instead:
+    /// ```rust
+    /// use std::any::{Any, TypeId};
+    ///
+    /// let any_box: Box<dyn Any> = Box::new(42_i32);
+    /// assert_eq!((*any_box).type_id(), TypeId::of::<i32>());
+    /// //          ^ dereference first, to call `type_id` on `dyn Any`
+    /// ```
+    #[clippy::version = "1.72.0"]
+    pub TYPE_ID_ON_BOX,
+    suspicious,
+    "calling `.type_id()` on `Box<dyn Any>`"
+}
+
 declare_clippy_lint! {
     /// ### What it does
     /// Detects `().hash(_)`.
@@ -3316,6 +3349,35 @@ declare_clippy_lint! {
     "checks for usage of `Iterator::fold` with a type that implements `Try`"
 }
 
+declare_clippy_lint! {
+    /// Looks for calls to [`Stdin::read_line`] to read a line from the standard input
+    /// into a string, then later attempting to parse this string into a type without first trimming it, which will
+    /// always fail because the string has a trailing newline in it.
+    ///
+    /// ### Why is this bad?
+    /// The `.parse()` call will always fail.
+    ///
+    /// ### Example
+    /// ```rust,ignore
+    /// let mut input = String::new();
+    /// std::io::stdin().read_line(&mut input).expect("Failed to read a line");
+    /// let num: i32 = input.parse().expect("Not a number!");
+    /// assert_eq!(num, 42); // we never even get here!
+    /// ```
+    /// Use instead:
+    /// ```rust,ignore
+    /// let mut input = String::new();
+    /// std::io::stdin().read_line(&mut input).expect("Failed to read a line");
+    /// let num: i32 = input.trim_end().parse().expect("Not a number!");
+    /// //                  ^^^^^^^^^^^ remove the trailing newline
+    /// assert_eq!(num, 42);
+    /// ```
+    #[clippy::version = "1.72.0"]
+    pub READ_LINE_WITHOUT_TRIM,
+    correctness,
+    "calling `Stdin::read_line`, then trying to parse it without first trimming"
+}
+
 pub struct Methods {
     avoid_breaking_exported_api: bool,
     msrv: Msrv,
@@ -3389,6 +3451,7 @@ impl_lint_pass!(Methods => [
     STRING_EXTEND_CHARS,
     ITER_CLONED_COLLECT,
     ITER_WITH_DRAIN,
+    TYPE_ID_ON_BOX,
     USELESS_ASREF,
     UNNECESSARY_FOLD,
     UNNECESSARY_FILTER_MAP,
@@ -3435,6 +3498,7 @@ impl_lint_pass!(Methods => [
     REPEAT_ONCE,
     STABLE_SORT_PRIMITIVE,
     UNIT_HASH,
+    READ_LINE_WITHOUT_TRIM,
     UNNECESSARY_SORT_BY,
     VEC_RESIZE_TO_ZERO,
     VERBOSE_FILE_READS,
@@ -3846,6 +3910,9 @@ impl Methods {
                 ("read_to_string", [_]) => {
                     verbose_file_reads::check(cx, expr, recv, verbose_file_reads::READ_TO_STRING_MSG);
                 },
+                ("read_line", [arg]) => {
+                    read_line_without_trim::check(cx, expr, recv, arg);
+                }
                 ("repeat", [arg]) => {
                     repeat_once::check(cx, expr, recv, arg);
                 },
@@ -3914,6 +3981,9 @@ impl Methods {
                 ("to_os_string" | "to_path_buf" | "to_vec", []) => {
                     implicit_clone::check(cx, name, expr, recv);
                 },
+                ("type_id", []) => {
+                    type_id_on_box::check(cx, recv, expr.span);
+                }
                 ("unwrap", []) => {
                     match method_call(recv) {
                         Some(("get", recv, [get_arg], _, _)) => {
@@ -3949,7 +4019,7 @@ impl Methods {
                     }
                     unnecessary_literal_unwrap::check(cx, expr, recv, name, args);
                 },
-                ("unwrap_or_default", []) => {
+                ("unwrap_or_default" | "unwrap_unchecked" | "unwrap_err_unchecked", []) => {
                     unnecessary_literal_unwrap::check(cx, expr, recv, name, args);
                 }
                 ("unwrap_or_else", [u_arg]) => {
@@ -4134,7 +4204,7 @@ impl SelfKind {
             };
 
             let Some(trait_def_id) = cx.tcx.get_diagnostic_item(trait_sym) else {
-                return false
+                return false;
             };
             implements_trait(cx, ty, trait_def_id, &[parent_ty.into()])
         }