mod bind_instead_of_map;
+mod bytecount;
+mod bytes_count_to_len;
mod bytes_nth;
+mod case_sensitive_file_extension_comparisons;
mod chars_cmp;
mod chars_cmp_with_unwrap;
mod chars_last_cmp;
mod flat_map_identity;
mod flat_map_option;
mod from_iter_instead_of_collect;
+mod get_first;
mod get_last_with_len;
mod get_unwrap;
mod implicit_clone;
mod iter_next_slice;
mod iter_nth;
mod iter_nth_zero;
+mod iter_on_single_or_empty_collections;
mod iter_overeager_cloned;
mod iter_skip_next;
mod iter_with_drain;
mod iterator_step_by_zero;
+mod manual_ok_or;
mod manual_saturating_arithmetic;
mod manual_str_repeat;
+mod map_clone;
mod map_collect_result_unit;
+mod map_err_ignore;
mod map_flatten;
mod map_identity;
mod map_unwrap_or;
+mod mut_mutex_lock;
mod needless_option_as_deref;
mod needless_option_take;
mod no_effect_replace;
mod obfuscated_if_else;
mod ok_expect;
+mod open_options;
mod option_as_ref_deref;
mod option_map_or_none;
mod option_map_unwrap_or;
mod or_fun_call;
mod or_then_unwrap;
+mod path_buf_push_overwrite;
+mod range_zip_with_len;
+mod repeat_once;
mod search_is_some;
mod single_char_add_str;
mod single_char_insert_string;
mod single_char_pattern;
mod single_char_push_string;
mod skip_while_next;
+mod stable_sort_primitive;
mod str_splitn;
mod string_extend_chars;
mod suspicious_map;
mod suspicious_splitn;
mod uninit_assumed_init;
+mod unit_hash;
mod unnecessary_filter_map;
mod unnecessary_fold;
mod unnecessary_iter_cloned;
mod unnecessary_join;
mod unnecessary_lazy_eval;
+mod unnecessary_sort_by;
mod unnecessary_to_owned;
mod unwrap_or_else_default;
mod unwrap_used;
mod useless_asref;
mod utils;
+mod vec_resize_to_zero;
+mod verbose_file_reads;
mod wrong_self_convention;
mod zst_offset;
use clippy_utils::consts::{constant, Constant};
use clippy_utils::diagnostics::{span_lint, span_lint_and_help};
use clippy_utils::ty::{contains_adt_constructor, contains_ty, implements_trait, is_copy, is_type_diagnostic_item};
-use clippy_utils::{contains_return, get_trait_def_id, iter_input_pats, meets_msrv, msrvs, paths, return_ty};
+use clippy_utils::{
+ contains_return, get_trait_def_id, is_trait_method, iter_input_pats, meets_msrv, msrvs, paths, return_ty,
+};
use if_chain::if_chain;
use rustc_hir as hir;
use rustc_hir::def::Res;
declare_clippy_lint! {
/// ### What it does
- /// Checks for `.unwrap()` calls on `Option`s and on `Result`s.
+ /// Checks for `.unwrap()` or `.unwrap_err()` calls on `Result`s and `.unwrap()` call on `Option`s.
///
/// ### Why is this bad?
/// It is better to handle the `None` or `Err` case,
/// option.expect("more helpful message");
/// result.expect("more helpful message");
/// ```
+ ///
+ /// If [expect_used](#expect_used) is enabled, instead:
+ /// ```rust,ignore
+ /// # let option = Some(1);
+ /// # let result: Result<usize, ()> = Ok(1);
+ /// option?;
+ ///
+ /// // or
+ ///
+ /// result?;
+ /// ```
#[clippy::version = "1.45.0"]
pub UNWRAP_USED,
restriction,
declare_clippy_lint! {
/// ### What it does
- /// Checks for `.expect()` calls on `Option`s and `Result`s.
+ /// Checks for `.expect()` or `.expect_err()` calls on `Result`s and `.expect()` call on `Option`s.
///
/// ### Why is this bad?
/// Usually it is better to handle the `None` or `Err` case.
/// "1234".replace("12", "12");
/// "1234".replacen("12", "12", 1);
/// ```
- #[clippy::version = "1.62.0"]
+ #[clippy::version = "1.63.0"]
pub NO_EFFECT_REPLACE,
suspicious,
"replace with no effect"
more clearly with `if .. else ..`"
}
+declare_clippy_lint! {
+ /// ### What it does
+ ///
+ /// Checks for calls to `iter`, `iter_mut` or `into_iter` on collections containing a single item
+ ///
+ /// ### Why is this bad?
+ ///
+ /// It is simpler to use the once function from the standard library:
+ ///
+ /// ### Example
+ ///
+ /// ```rust
+ /// let a = [123].iter();
+ /// let b = Some(123).into_iter();
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// use std::iter;
+ /// let a = iter::once(&123);
+ /// let b = iter::once(123);
+ /// ```
+ ///
+ /// ### Known problems
+ ///
+ /// The type of the resulting iterator might become incompatible with its usage
+ #[clippy::version = "1.64.0"]
+ pub ITER_ON_SINGLE_ITEMS,
+ nursery,
+ "Iterator for array of length 1"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ ///
+ /// Checks for calls to `iter`, `iter_mut` or `into_iter` on empty collections
+ ///
+ /// ### Why is this bad?
+ ///
+ /// It is simpler to use the empty function from the standard library:
+ ///
+ /// ### Example
+ ///
+ /// ```rust
+ /// use std::{slice, option};
+ /// let a: slice::Iter<i32> = [].iter();
+ /// let f: option::IntoIter<i32> = None.into_iter();
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// use std::iter;
+ /// let a: iter::Empty<i32> = iter::empty();
+ /// let b: iter::Empty<i32> = iter::empty();
+ /// ```
+ ///
+ /// ### Known problems
+ ///
+ /// The type of the resulting iterator might become incompatible with its usage
+ #[clippy::version = "1.64.0"]
+ pub ITER_ON_EMPTY_COLLECTIONS,
+ nursery,
+ "Iterator for empty array"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for naive byte counts
+ ///
+ /// ### Why is this bad?
+ /// The [`bytecount`](https://crates.io/crates/bytecount)
+ /// crate has methods to count your bytes faster, especially for large slices.
+ ///
+ /// ### Known problems
+ /// If you have predominantly small slices, the
+ /// `bytecount::count(..)` method may actually be slower. However, if you can
+ /// ensure that less than 2³²-1 matches arise, the `naive_count_32(..)` can be
+ /// faster in those cases.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let vec = vec![1_u8];
+ /// let count = vec.iter().filter(|x| **x == 0u8).count();
+ /// ```
+ ///
+ /// Use instead:
+ /// ```rust,ignore
+ /// # let vec = vec![1_u8];
+ /// let count = bytecount::count(&vec, 0u8);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub NAIVE_BYTECOUNT,
+ pedantic,
+ "use of naive `<slice>.filter(|&x| x == y).count()` to count byte values"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// It checks for `str::bytes().count()` and suggests replacing it with
+ /// `str::len()`.
+ ///
+ /// ### Why is this bad?
+ /// `str::bytes().count()` is longer and may not be as performant as using
+ /// `str::len()`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// "hello".bytes().count();
+ /// String::from("hello").bytes().count();
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// "hello".len();
+ /// String::from("hello").len();
+ /// ```
+ #[clippy::version = "1.62.0"]
+ pub BYTES_COUNT_TO_LEN,
+ complexity,
+ "Using `bytes().count()` when `len()` performs the same functionality"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for calls to `ends_with` with possible file extensions
+ /// and suggests to use a case-insensitive approach instead.
+ ///
+ /// ### Why is this bad?
+ /// `ends_with` is case-sensitive and may not detect files with a valid extension.
+ ///
+ /// ### Example
+ /// ```rust
+ /// fn is_rust_file(filename: &str) -> bool {
+ /// filename.ends_with(".rs")
+ /// }
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// fn is_rust_file(filename: &str) -> bool {
+ /// let filename = std::path::Path::new(filename);
+ /// filename.extension()
+ /// .map_or(false, |ext| ext.eq_ignore_ascii_case("rs"))
+ /// }
+ /// ```
+ #[clippy::version = "1.51.0"]
+ pub CASE_SENSITIVE_FILE_EXTENSION_COMPARISONS,
+ pedantic,
+ "Checks for calls to ends_with with case-sensitive file extensions"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for using `x.get(0)` instead of
+ /// `x.first()`.
+ ///
+ /// ### Why is this bad?
+ /// Using `x.first()` is easier to read and has the same
+ /// result.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let x = vec![2, 3, 5];
+ /// let first_element = x.get(0);
+ /// ```
+ ///
+ /// Use instead:
+ /// ```rust
+ /// let x = vec![2, 3, 5];
+ /// let first_element = x.first();
+ /// ```
+ #[clippy::version = "1.63.0"]
+ pub GET_FIRST,
+ style,
+ "Using `x.get(0)` when `x.first()` is simpler"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ ///
+ /// Finds patterns that reimplement `Option::ok_or`.
+ ///
+ /// ### Why is this bad?
+ ///
+ /// Concise code helps focusing on behavior instead of boilerplate.
+ ///
+ /// ### Examples
+ /// ```rust
+ /// let foo: Option<i32> = None;
+ /// foo.map_or(Err("error"), |v| Ok(v));
+ /// ```
+ ///
+ /// Use instead:
+ /// ```rust
+ /// let foo: Option<i32> = None;
+ /// foo.ok_or("error");
+ /// ```
+ #[clippy::version = "1.49.0"]
+ pub MANUAL_OK_OR,
+ pedantic,
+ "finds patterns that can be encoded more concisely with `Option::ok_or`"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `map(|x| x.clone())` or
+ /// dereferencing closures for `Copy` types, on `Iterator` or `Option`,
+ /// and suggests `cloned()` or `copied()` instead
+ ///
+ /// ### Why is this bad?
+ /// Readability, this can be written more concisely
+ ///
+ /// ### Example
+ /// ```rust
+ /// let x = vec![42, 43];
+ /// let y = x.iter();
+ /// let z = y.map(|i| *i);
+ /// ```
+ ///
+ /// The correct use would be:
+ ///
+ /// ```rust
+ /// let x = vec![42, 43];
+ /// let y = x.iter();
+ /// let z = y.cloned();
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub MAP_CLONE,
+ style,
+ "using `iterator.map(|x| x.clone())`, or dereferencing closures for `Copy` types"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for instances of `map_err(|_| Some::Enum)`
+ ///
+ /// ### Why is this bad?
+ /// This `map_err` throws away the original error rather than allowing the enum to contain and report the cause of the error
+ ///
+ /// ### Example
+ /// Before:
+ /// ```rust
+ /// use std::fmt;
+ ///
+ /// #[derive(Debug)]
+ /// enum Error {
+ /// Indivisible,
+ /// Remainder(u8),
+ /// }
+ ///
+ /// impl fmt::Display for Error {
+ /// fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ /// match self {
+ /// Error::Indivisible => write!(f, "could not divide input by three"),
+ /// Error::Remainder(remainder) => write!(
+ /// f,
+ /// "input is not divisible by three, remainder = {}",
+ /// remainder
+ /// ),
+ /// }
+ /// }
+ /// }
+ ///
+ /// impl std::error::Error for Error {}
+ ///
+ /// fn divisible_by_3(input: &str) -> Result<(), Error> {
+ /// input
+ /// .parse::<i32>()
+ /// .map_err(|_| Error::Indivisible)
+ /// .map(|v| v % 3)
+ /// .and_then(|remainder| {
+ /// if remainder == 0 {
+ /// Ok(())
+ /// } else {
+ /// Err(Error::Remainder(remainder as u8))
+ /// }
+ /// })
+ /// }
+ /// ```
+ ///
+ /// After:
+ /// ```rust
+ /// use std::{fmt, num::ParseIntError};
+ ///
+ /// #[derive(Debug)]
+ /// enum Error {
+ /// Indivisible(ParseIntError),
+ /// Remainder(u8),
+ /// }
+ ///
+ /// impl fmt::Display for Error {
+ /// fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ /// match self {
+ /// Error::Indivisible(_) => write!(f, "could not divide input by three"),
+ /// Error::Remainder(remainder) => write!(
+ /// f,
+ /// "input is not divisible by three, remainder = {}",
+ /// remainder
+ /// ),
+ /// }
+ /// }
+ /// }
+ ///
+ /// impl std::error::Error for Error {
+ /// fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+ /// match self {
+ /// Error::Indivisible(source) => Some(source),
+ /// _ => None,
+ /// }
+ /// }
+ /// }
+ ///
+ /// fn divisible_by_3(input: &str) -> Result<(), Error> {
+ /// input
+ /// .parse::<i32>()
+ /// .map_err(Error::Indivisible)
+ /// .map(|v| v % 3)
+ /// .and_then(|remainder| {
+ /// if remainder == 0 {
+ /// Ok(())
+ /// } else {
+ /// Err(Error::Remainder(remainder as u8))
+ /// }
+ /// })
+ /// }
+ /// ```
+ #[clippy::version = "1.48.0"]
+ pub MAP_ERR_IGNORE,
+ restriction,
+ "`map_err` should not ignore the original error"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `&mut Mutex::lock` calls
+ ///
+ /// ### Why is this bad?
+ /// `Mutex::lock` is less efficient than
+ /// calling `Mutex::get_mut`. In addition you also have a statically
+ /// guarantee that the mutex isn't locked, instead of just a runtime
+ /// guarantee.
+ ///
+ /// ### Example
+ /// ```rust
+ /// use std::sync::{Arc, Mutex};
+ ///
+ /// let mut value_rc = Arc::new(Mutex::new(42_u8));
+ /// let value_mutex = Arc::get_mut(&mut value_rc).unwrap();
+ ///
+ /// let mut value = value_mutex.lock().unwrap();
+ /// *value += 1;
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// use std::sync::{Arc, Mutex};
+ ///
+ /// let mut value_rc = Arc::new(Mutex::new(42_u8));
+ /// let value_mutex = Arc::get_mut(&mut value_rc).unwrap();
+ ///
+ /// let value = value_mutex.get_mut().unwrap();
+ /// *value += 1;
+ /// ```
+ #[clippy::version = "1.49.0"]
+ pub MUT_MUTEX_LOCK,
+ style,
+ "`&mut Mutex::lock` does unnecessary locking"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for duplicate open options as well as combinations
+ /// that make no sense.
+ ///
+ /// ### Why is this bad?
+ /// In the best case, the code will be harder to read than
+ /// necessary. I don't know the worst case.
+ ///
+ /// ### Example
+ /// ```rust
+ /// use std::fs::OpenOptions;
+ ///
+ /// OpenOptions::new().read(true).truncate(true);
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub NONSENSICAL_OPEN_OPTIONS,
+ correctness,
+ "nonsensical combination of options for opening a file"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ ///* Checks for [push](https://doc.rust-lang.org/std/path/struct.PathBuf.html#method.push)
+ /// calls on `PathBuf` that can cause overwrites.
+ ///
+ /// ### Why is this bad?
+ /// Calling `push` with a root path at the start can overwrite the
+ /// previous defined path.
+ ///
+ /// ### Example
+ /// ```rust
+ /// use std::path::PathBuf;
+ ///
+ /// let mut x = PathBuf::from("/foo");
+ /// x.push("/bar");
+ /// assert_eq!(x, PathBuf::from("/bar"));
+ /// ```
+ /// Could be written:
+ ///
+ /// ```rust
+ /// use std::path::PathBuf;
+ ///
+ /// let mut x = PathBuf::from("/foo");
+ /// x.push("bar");
+ /// assert_eq!(x, PathBuf::from("/foo/bar"));
+ /// ```
+ #[clippy::version = "1.36.0"]
+ pub PATH_BUF_PUSH_OVERWRITE,
+ nursery,
+ "calling `push` with file system root on `PathBuf` can overwrite it"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for zipping a collection with the range of
+ /// `0.._.len()`.
+ ///
+ /// ### Why is this bad?
+ /// The code is better expressed with `.enumerate()`.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # let x = vec![1];
+ /// let _ = x.iter().zip(0..x.len());
+ /// ```
+ ///
+ /// Use instead:
+ /// ```rust
+ /// # let x = vec![1];
+ /// let _ = x.iter().enumerate();
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
+ pub RANGE_ZIP_WITH_LEN,
+ complexity,
+ "zipping iterator with a range when `enumerate()` would do"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for usage of `.repeat(1)` and suggest the following method for each types.
+ /// - `.to_string()` for `str`
+ /// - `.clone()` for `String`
+ /// - `.to_vec()` for `slice`
+ ///
+ /// The lint will evaluate constant expressions and values as arguments of `.repeat(..)` and emit a message if
+ /// they are equivalent to `1`. (Related discussion in [rust-clippy#7306](https://github.com/rust-lang/rust-clippy/issues/7306))
+ ///
+ /// ### Why is this bad?
+ /// For example, `String.repeat(1)` is equivalent to `.clone()`. If cloning
+ /// the string is the intention behind this, `clone()` should be used.
+ ///
+ /// ### Example
+ /// ```rust
+ /// fn main() {
+ /// let x = String::from("hello world").repeat(1);
+ /// }
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// fn main() {
+ /// let x = String::from("hello world").clone();
+ /// }
+ /// ```
+ #[clippy::version = "1.47.0"]
+ pub REPEAT_ONCE,
+ complexity,
+ "using `.repeat(1)` instead of `String.clone()`, `str.to_string()` or `slice.to_vec()` "
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// When sorting primitive values (integers, bools, chars, as well
+ /// as arrays, slices, and tuples of such items), it is typically better to
+ /// use an unstable sort than a stable sort.
+ ///
+ /// ### Why is this bad?
+ /// Typically, using a stable sort consumes more memory and cpu cycles.
+ /// Because values which compare equal are identical, preserving their
+ /// relative order (the guarantee that a stable sort provides) means
+ /// nothing, while the extra costs still apply.
+ ///
+ /// ### Known problems
+ ///
+ /// As pointed out in
+ /// [issue #8241](https://github.com/rust-lang/rust-clippy/issues/8241),
+ /// a stable sort can instead be significantly faster for certain scenarios
+ /// (eg. when a sorted vector is extended with new data and resorted).
+ ///
+ /// For more information and benchmarking results, please refer to the
+ /// issue linked above.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let mut vec = vec![2, 1, 3];
+ /// vec.sort();
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// let mut vec = vec![2, 1, 3];
+ /// vec.sort_unstable();
+ /// ```
+ #[clippy::version = "1.47.0"]
+ pub STABLE_SORT_PRIMITIVE,
+ pedantic,
+ "use of sort() when sort_unstable() is equivalent"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Detects `().hash(_)`.
+ ///
+ /// ### Why is this bad?
+ /// Hashing a unit value doesn't do anything as the implementation of `Hash` for `()` is a no-op.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # use std::hash::Hash;
+ /// # use std::collections::hash_map::DefaultHasher;
+ /// # enum Foo { Empty, WithValue(u8) }
+ /// # use Foo::*;
+ /// # let mut state = DefaultHasher::new();
+ /// # let my_enum = Foo::Empty;
+ /// match my_enum {
+ /// Empty => ().hash(&mut state),
+ /// WithValue(x) => x.hash(&mut state),
+ /// }
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// # use std::hash::Hash;
+ /// # use std::collections::hash_map::DefaultHasher;
+ /// # enum Foo { Empty, WithValue(u8) }
+ /// # use Foo::*;
+ /// # let mut state = DefaultHasher::new();
+ /// # let my_enum = Foo::Empty;
+ /// match my_enum {
+ /// Empty => 0_u8.hash(&mut state),
+ /// WithValue(x) => x.hash(&mut state),
+ /// }
+ /// ```
+ #[clippy::version = "1.58.0"]
+ pub UNIT_HASH,
+ correctness,
+ "hashing a unit value, which does nothing"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Detects uses of `Vec::sort_by` passing in a closure
+ /// which compares the two arguments, either directly or indirectly.
+ ///
+ /// ### Why is this bad?
+ /// It is more clear to use `Vec::sort_by_key` (or `Vec::sort` if
+ /// possible) than to use `Vec::sort_by` and a more complicated
+ /// closure.
+ ///
+ /// ### Known problems
+ /// If the suggested `Vec::sort_by_key` uses Reverse and it isn't already
+ /// imported by a use statement, then it will need to be added manually.
+ ///
+ /// ### Example
+ /// ```rust
+ /// # struct A;
+ /// # impl A { fn foo(&self) {} }
+ /// # let mut vec: Vec<A> = Vec::new();
+ /// vec.sort_by(|a, b| a.foo().cmp(&b.foo()));
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// # struct A;
+ /// # impl A { fn foo(&self) {} }
+ /// # let mut vec: Vec<A> = Vec::new();
+ /// vec.sort_by_key(|a| a.foo());
+ /// ```
+ #[clippy::version = "1.46.0"]
+ pub UNNECESSARY_SORT_BY,
+ complexity,
+ "Use of `Vec::sort_by` when `Vec::sort_by_key` or `Vec::sort` would be clearer"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Finds occurrences of `Vec::resize(0, an_int)`
+ ///
+ /// ### Why is this bad?
+ /// This is probably an argument inversion mistake.
+ ///
+ /// ### Example
+ /// ```rust
+ /// vec!(1, 2, 3, 4, 5).resize(0, 5)
+ /// ```
+ ///
+ /// Use instead:
+ /// ```rust
+ /// vec!(1, 2, 3, 4, 5).clear()
+ /// ```
+ #[clippy::version = "1.46.0"]
+ pub VEC_RESIZE_TO_ZERO,
+ correctness,
+ "emptying a vector with `resize(0, an_int)` instead of `clear()` is probably an argument inversion mistake"
+}
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for use of File::read_to_end and File::read_to_string.
+ ///
+ /// ### Why is this bad?
+ /// `fs::{read, read_to_string}` provide the same functionality when `buf` is empty with fewer imports and no intermediate values.
+ /// See also: [fs::read docs](https://doc.rust-lang.org/std/fs/fn.read.html), [fs::read_to_string docs](https://doc.rust-lang.org/std/fs/fn.read_to_string.html)
+ ///
+ /// ### Example
+ /// ```rust,no_run
+ /// # use std::io::Read;
+ /// # use std::fs::File;
+ /// let mut f = File::open("foo.txt").unwrap();
+ /// let mut bytes = Vec::new();
+ /// f.read_to_end(&mut bytes).unwrap();
+ /// ```
+ /// Can be written more concisely as
+ /// ```rust,no_run
+ /// # use std::fs;
+ /// let mut bytes = fs::read("foo.txt").unwrap();
+ /// ```
+ #[clippy::version = "1.44.0"]
+ pub VERBOSE_FILE_READS,
+ restriction,
+ "use of `File::read_to_end` or `File::read_to_string`"
+}
+
pub struct Methods {
avoid_breaking_exported_api: bool,
msrv: Option<RustcVersion>,
NEEDLESS_OPTION_TAKE,
NO_EFFECT_REPLACE,
OBFUSCATED_IF_ELSE,
+ ITER_ON_SINGLE_ITEMS,
+ ITER_ON_EMPTY_COLLECTIONS,
+ NAIVE_BYTECOUNT,
+ BYTES_COUNT_TO_LEN,
+ CASE_SENSITIVE_FILE_EXTENSION_COMPARISONS,
+ GET_FIRST,
+ MANUAL_OK_OR,
+ MAP_CLONE,
+ MAP_ERR_IGNORE,
+ MUT_MUTEX_LOCK,
+ NONSENSICAL_OPEN_OPTIONS,
+ PATH_BUF_PUSH_OVERWRITE,
+ RANGE_ZIP_WITH_LEN,
+ REPEAT_ONCE,
+ STABLE_SORT_PRIMITIVE,
+ UNIT_HASH,
+ UNNECESSARY_SORT_BY,
+ VEC_RESIZE_TO_ZERO,
+ VERBOSE_FILE_READS,
]);
/// Extracts a method call name, args, and `Span` of the method name.
},
_ => {},
},
- ("count", []) => match method_call(recv) {
+ ("count", []) if is_trait_method(cx, expr, sym::Iterator) => match method_call(recv) {
Some(("cloned", [recv2], _)) => iter_overeager_cloned::check(cx, expr, recv, recv2, true, false),
Some((name2 @ ("into_iter" | "iter" | "iter_mut"), [recv2], _)) => {
iter_count::check(cx, expr, recv2, name2);
},
Some(("map", [_, arg], _)) => suspicious_map::check(cx, expr, recv, arg),
+ Some(("filter", [recv2, arg], _)) => bytecount::check(cx, expr, recv2, arg),
+ Some(("bytes", [recv2], _)) => bytes_count_to_len::check(cx, expr, recv, recv2),
_ => {},
},
("drain", [arg]) => {
iter_with_drain::check(cx, expr, recv, span, arg);
},
+ ("ends_with", [arg]) => {
+ if let ExprKind::MethodCall(_, _, span) = expr.kind {
+ case_sensitive_file_extension_comparisons::check(cx, expr, span, recv, arg);
+ }
+ },
("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, self.msrv, span, err_span),
- _ => expect_used::check(cx, expr, recv, self.allow_expect_in_tests),
+ _ => expect_used::check(cx, expr, recv, false, self.allow_expect_in_tests),
},
+ ("expect_err", [_]) => expect_used::check(cx, expr, recv, true, self.allow_expect_in_tests),
("extend", [arg]) => {
string_extend_chars::check(cx, expr, recv, arg);
extend_with_drain::check(cx, expr, recv, arg);
inspect_for_each::check(cx, expr, span2);
}
},
- ("get", [arg]) => get_last_with_len::check(cx, expr, recv, arg),
+ ("get", [arg]) => {
+ get_first::check(cx, expr, recv, arg);
+ get_last_with_len::check(cx, expr, recv, arg);
+ },
("get_or_insert_with", [arg]) => unnecessary_lazy_eval::check(cx, expr, recv, arg, "get_or_insert"),
+ ("hash", [arg]) => {
+ unit_hash::check(cx, expr, recv, arg);
+ },
("is_file", []) => filetype_is_file::check(cx, expr, recv),
("is_digit", [radix]) => is_digit_ascii_radix::check(cx, expr, recv, radix, self.msrv),
("is_none", []) => check_is_some_is_none(cx, expr, recv, false),
("is_some", []) => check_is_some_is_none(cx, expr, recv, true),
+ ("iter" | "iter_mut" | "into_iter", []) => {
+ iter_on_single_or_empty_collections::check(cx, expr, name, recv);
+ },
("join", [join_arg]) => {
if let Some(("collect", _, span)) = method_call(recv) {
unnecessary_join::check(cx, expr, recv, join_arg, span);
}
}
},
+ ("lock", []) => {
+ mut_mutex_lock::check(cx, expr, recv, span);
+ },
(name @ ("map" | "map_err"), [m_arg]) => {
+ if name == "map" {
+ map_clone::check(cx, expr, recv, m_arg, self.msrv);
+ } else {
+ map_err_ignore::check(cx, expr, 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, self.msrv),
}
map_identity::check(cx, expr, recv, m_arg, name, span);
},
- ("map_or", [def, map]) => option_map_or_none::check(cx, expr, recv, def, map),
+ ("map_or", [def, map]) => {
+ option_map_or_none::check(cx, expr, recv, def, map);
+ manual_ok_or::check(cx, expr, recv, def, map);
+ },
("next", []) => {
if let Some((name2, [recv2, args2 @ ..], _)) = method_call(recv) {
match (name2, args2) {
_ => iter_nth_zero::check(cx, expr, recv, n_arg),
},
("ok_or_else", [arg]) => unnecessary_lazy_eval::check(cx, expr, recv, arg, "ok_or"),
+ ("open", [_]) => {
+ open_options::check(cx, expr, recv);
+ },
("or_else", [arg]) => {
if !bind_instead_of_map::ResultOrElseErrInfo::check(cx, expr, recv, arg) {
unnecessary_lazy_eval::check(cx, expr, recv, arg, "or");
}
},
+ ("push", [arg]) => {
+ path_buf_push_overwrite::check(cx, expr, arg);
+ },
+ ("read_to_end", [_]) => {
+ verbose_file_reads::check(cx, expr, recv, verbose_file_reads::READ_TO_END_MSG);
+ },
+ ("read_to_string", [_]) => {
+ verbose_file_reads::check(cx, expr, recv, verbose_file_reads::READ_TO_STRING_MSG);
+ },
+ ("repeat", [arg]) => {
+ repeat_once::check(cx, expr, recv, arg);
+ },
+ ("resize", [count_arg, default_arg]) => {
+ vec_resize_to_zero::check(cx, expr, count_arg, default_arg, span);
+ },
+ ("sort", []) => {
+ stable_sort_primitive::check(cx, expr, recv);
+ },
+ ("sort_by", [arg]) => {
+ unnecessary_sort_by::check(cx, expr, recv, arg, false);
+ },
+ ("sort_unstable_by", [arg]) => {
+ unnecessary_sort_by::check(cx, expr, recv, arg, true);
+ },
("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);
},
_ => {},
}
- unwrap_used::check(cx, expr, recv, self.allow_unwrap_in_tests);
+ unwrap_used::check(cx, expr, recv, false, self.allow_unwrap_in_tests);
},
+ ("unwrap_err", []) => unwrap_used::check(cx, expr, recv, true, self.allow_unwrap_in_tests),
("unwrap_or", [u_arg]) => match method_call(recv) {
Some((arith @ ("checked_add" | "checked_sub" | "checked_mul"), [lhs, rhs], _)) => {
manual_saturating_arithmetic::check(cx, expr, lhs, rhs, u_arg, &arith["checked_".len()..]);
("replace" | "replacen", [arg1, arg2] | [arg1, arg2, _]) => {
no_effect_replace::check(cx, expr, arg1, arg2);
},
+ ("zip", [arg]) => {
+ if let ExprKind::MethodCall(name, [iter_recv], _) = recv.kind
+ && name.ident.name == sym::iter
+ {
+ range_zip_with_len::check(cx, expr, iter_recv, arg);
+ }
+ },
_ => {},
}
}
projects / rust.git / blobdiff