mod clone_on_copy;
mod clone_on_ref_ptr;
mod cloned_instead_of_copied;
+mod err_expect;
mod expect_fun_call;
mod expect_used;
mod extend_with_drain;
mod map_flatten;
mod map_identity;
mod map_unwrap_or;
+mod needless_option_as_deref;
mod ok_expect;
mod option_as_ref_deref;
mod option_map_or_none;
mod option_map_unwrap_or;
mod or_fun_call;
+mod or_then_unwrap;
mod search_is_some;
mod single_char_add_str;
mod single_char_insert_string;
mod unnecessary_filter_map;
mod unnecessary_fold;
mod unnecessary_iter_cloned;
+mod unnecessary_join;
mod unnecessary_lazy_eval;
mod unnecessary_to_owned;
mod unwrap_or_else_default;
"using `ok().expect()`, which gives worse error messages than calling `expect` directly on the Result"
}
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `.err().expect()` calls on the `Result` type.
+ ///
+ /// ### Why is this bad?
+ /// `.expect_err()` can be called directly to avoid the extra type conversion from `err()`.
+ ///
+ /// ### Example
+ /// ```should_panic
+ /// let x: Result<u32, &str> = Ok(10);
+ /// x.err().expect("Testing err().expect()");
+ /// ```
+ /// Use instead:
+ /// ```should_panic
+ /// let x: Result<u32, &str> = Ok(10);
+ /// x.expect_err("Testing expect_err");
+ /// ```
+ #[clippy::version = "1.61.0"]
+ pub ERR_EXPECT,
+ style,
+ r#"using `.err().expect("")` when `.expect_err("")` can be used"#
+}
+
declare_clippy_lint! {
/// ### What it does
/// Checks for usages of `_.unwrap_or_else(Default::default)` on `Option` and
"using any `*or` method with a function call, which suggests `*or_else`"
}
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `.or(…).unwrap()` calls to Options and Results.
+ ///
+ /// ### Why is this bad?
+ /// You should use `.unwrap_or(…)` instead for clarity.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let fallback = "fallback";
+ /// // Result
+ /// # type Error = &'static str;
+ /// # let result: Result<&str, Error> = Err("error");
+ /// let value = result.or::<Error>(Ok(fallback)).unwrap();
+ ///
+ /// // Option
+ /// # let option: Option<&str> = None;
+ /// let value = option.or(Some(fallback)).unwrap();
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// # let fallback = "fallback";
+ /// // Result
+ /// # let result: Result<&str, &str> = Err("error");
+ /// let value = result.unwrap_or(fallback);
+ ///
+ /// // Option
+ /// # let option: Option<&str> = None;
+ /// let value = option.unwrap_or(fallback);
+ /// ```
+ #[clippy::version = "1.61.0"]
+ pub OR_THEN_UNWRAP,
+ complexity,
+ "checks for `.or(…).unwrap()` calls to Options and Results."
+}
+
declare_clippy_lint! {
/// ### What it does
/// Checks for calls to `.expect(&format!(...))`, `.expect(foo(..))`,
/// ```
#[clippy::version = "1.61.0"]
pub ITER_WITH_DRAIN,
- perf,
+ nursery,
"replace `.drain(..)` with `.into_iter()`"
}
"unnecessary calls to `to_owned`-like functions"
}
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for use of `.collect::<Vec<String>>().join("")` on iterators.
+ ///
+ /// ### Why is this bad?
+ /// `.collect::<String>()` is more concise and might be more performant
+ ///
+ /// ### Example
+ /// ```rust
+ /// let vector = vec!["hello", "world"];
+ /// let output = vector.iter().map(|item| item.to_uppercase()).collect::<Vec<String>>().join("");
+ /// println!("{}", output);
+ /// ```
+ /// The correct use would be:
+ /// ```rust
+ /// let vector = vec!["hello", "world"];
+ /// let output = vector.iter().map(|item| item.to_uppercase()).collect::<String>();
+ /// println!("{}", output);
+ /// ```
+ /// ### Known problems
+ /// While `.collect::<String>()` is sometimes more performant, there are cases where
+ /// using `.collect::<String>()` over `.collect::<Vec<String>>().join("")`
+ /// will prevent loop unrolling and will result in a negative performance impact.
+ ///
+ /// Additionlly, differences have been observed between aarch64 and x86_64 assembly output,
+ /// with aarch64 tending to producing faster assembly in more cases when using `.collect::<String>()`
+ #[clippy::version = "1.61.0"]
+ pub UNNECESSARY_JOIN,
+ pedantic,
+ "using `.collect::<Vec<String>>().join(\"\")` on an iterator"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for no-op uses of `Option::{as_deref, as_deref_mut}`,
+ /// for example, `Option<&T>::as_deref()` returns the same type.
+ ///
+ /// ### Why is this bad?
+ /// Redundant code and improving readability.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let a = Some(&1);
+ /// let b = a.as_deref(); // goes from Option<&i32> to Option<&i32>
+ /// ```
+ /// Could be written as:
+ /// ```rust
+ /// let a = Some(&1);
+ /// let b = a;
+ /// ```
+ #[clippy::version = "1.57.0"]
+ pub NEEDLESS_OPTION_AS_DEREF,
+ complexity,
+ "no-op use of `deref` or `deref_mut` method to `Option`."
+}
+
pub struct Methods {
avoid_breaking_exported_api: bool,
msrv: Option<RustcVersion>,
OPTION_MAP_OR_NONE,
BIND_INSTEAD_OF_MAP,
OR_FUN_CALL,
+ OR_THEN_UNWRAP,
EXPECT_FUN_CALL,
CHARS_NEXT_CMP,
CHARS_LAST_CMP,
MANUAL_SPLIT_ONCE,
NEEDLESS_SPLITN,
UNNECESSARY_TO_OWNED,
+ UNNECESSARY_JOIN,
+ ERR_EXPECT,
+ NEEDLESS_OPTION_AS_DEREF,
]);
/// Extracts a method call name, args, and `Span` of the method name.
unnecessary_lazy_eval::check(cx, expr, recv, arg, "and");
}
},
+ ("as_deref" | "as_deref_mut", []) => {
+ needless_option_as_deref::check(cx, expr, recv, name);
+ },
("as_mut", []) => useless_asref::check(cx, expr, "as_mut", recv),
("as_ref", []) => useless_asref::check(cx, expr, "as_ref", recv),
("assume_init", []) => uninit_assumed_init::check(cx, expr, recv),
},
("expect", [_]) => match method_call(recv) {
Some(("ok", [recv], _)) => ok_expect::check(cx, expr, recv),
+ Some(("err", [recv], err_span)) => err_expect::check(cx, expr, recv, msrv, span, err_span),
_ => expect_used::check(cx, expr, recv),
},
("extend", [arg]) => {
flat_map_option::check(cx, expr, arg, span);
},
(name @ "flatten", args @ []) => match method_call(recv) {
- Some(("map", [recv, map_arg], _)) => map_flatten::check(cx, expr, recv, map_arg),
+ Some(("map", [recv, map_arg], map_span)) => map_flatten::check(cx, expr, recv, map_arg, map_span),
Some(("cloned", [recv2], _)) => iter_overeager_cloned::check(cx, expr, recv2, name, args),
_ => {},
},
("is_file", []) => filetype_is_file::check(cx, expr, recv),
("is_none", []) => check_is_some_is_none(cx, expr, recv, false),
("is_some", []) => check_is_some_is_none(cx, expr, recv, true),
+ ("join", [join_arg]) => {
+ if let Some(("collect", _, span)) = method_call(recv) {
+ unnecessary_join::check(cx, expr, recv, join_arg, span);
+ }
+ },
("last", args @ []) | ("skip", args @ [_]) => {
if let Some((name2, [recv2, args2 @ ..], _span2)) = method_call(recv) {
if let ("cloned", []) = (name2, args2) {
}
}
},
- ("map", [m_arg]) => {
+ (name @ ("map" | "map_err"), [m_arg]) => {
if let Some((name, [recv2, args @ ..], span2)) = method_call(recv) {
match (name, args) {
("as_mut", []) => option_as_ref_deref::check(cx, expr, recv2, m_arg, true, msrv),
_ => {},
}
}
- map_identity::check(cx, expr, recv, m_arg, span);
+ map_identity::check(cx, expr, recv, m_arg, name, span);
},
("map_or", [def, map]) => option_map_or_none::check(cx, expr, recv, def, map),
(name @ "next", args @ []) => {
("splitn" | "rsplitn", [count_arg, pat_arg]) => {
if let Some((Constant::Int(count), _)) = constant(cx, cx.typeck_results(), count_arg) {
suspicious_splitn::check(cx, name, expr, recv, count);
- if count == 2 && meets_msrv(msrv, &msrvs::STR_SPLIT_ONCE) {
- str_splitn::check_manual_split_once(cx, name, expr, recv, pat_arg);
- }
- if count >= 2 {
- str_splitn::check_needless_splitn(cx, name, expr, recv, pat_arg, count);
- }
+ str_splitn::check(cx, name, expr, recv, pat_arg, count, msrv);
}
},
("splitn_mut" | "rsplitn_mut", [count_arg, _]) => {
Some(("get_mut", [recv, get_arg], _)) => {
get_unwrap::check(cx, expr, recv, get_arg, true);
},
+ Some(("or", [recv, or_arg], or_span)) => {
+ or_then_unwrap::check(cx, expr, recv, or_arg, or_span);
+ },
_ => {},
}
unwrap_used::check(cx, expr, recv);
projects / rust.git / blobdiff