lint!: upgrade perfectionist

.github/copilot-instructions.md

@@ -12,7 +12,6 @@ Read and follow the CONTRIBUTING.md file in this repository for all code style c
 - Use descriptive names for variables and closure parameters. Single letters are permitted only in these cases: (1) conventional names like `n` for count or `f` for formatter; (2) comparison closures like `|a, b|`; (3) trivial single-expression closures; (4) fold accumulators; (5) index variables `i`/`j`/`k` in short closures or index-based loops; and (6) test fixtures with identical roles. Single letters are never permitted in multi-line functions or closures.
 - Use `pipe-trait` to chain through unary functions such as constructors, `Some`, `Ok`, and free functions. Use it to flatten nested calls and to continue method chains. Do not use it for simple standalone calls; prefer `foo(value)` over `value.pipe(foo)`.
 - Prefer `where` clauses when a type has multiple trait bounds.
-- Derive order: standard traits, then comparison traits, then `Hash`, then `derive_more`, then feature-gated derives.
 - For error types, only derive `Display` and `Error` from `derive_more` when each is actually needed. Not all displayable types are errors.
 - Minimize `unwrap()` in non-test code. Use proper error handling instead.
 - Prefer `#[cfg_attr(..., ignore = "reason")]` over `#[cfg(...)]` when skipping tests. Use `#[cfg]` on tests only when the code cannot compile under the condition, such as when it references types or functions that do not exist on other platforms.

AGENTS.md

@@ -12,7 +12,6 @@ Read and follow the CONTRIBUTING.md file in this repository for all code style c
 - Use descriptive names for variables and closure parameters. Single letters are permitted only in these cases: (1) conventional names like `n` for count or `f` for formatter; (2) comparison closures like `|a, b|`; (3) trivial single-expression closures; (4) fold accumulators; (5) index variables `i`/`j`/`k` in short closures or index-based loops; and (6) test fixtures with identical roles. Single letters are never permitted in multi-line functions or closures.
 - Use `pipe-trait` to chain through unary functions such as constructors, `Some`, `Ok`, and free functions. Use it to flatten nested calls and to continue method chains. Do not use it for simple standalone calls; prefer `foo(value)` over `value.pipe(foo)`.
 - Prefer `where` clauses when a type has multiple trait bounds.
-- Derive order: standard traits, then comparison traits, then `Hash`, then `derive_more`, then feature-gated derives.
 - For error types, only derive `Display` and `Error` from `derive_more` when each is actually needed. Not all displayable types are errors.
 - Minimize `unwrap()` in non-test code. Use proper error handling instead.
 - Prefer `#[cfg_attr(..., ignore = "reason")]` over `#[cfg(...)]` when skipping tests. Use `#[cfg]` on tests only when the code cannot compile under the condition, such as when it references types or functions that do not exist on other platforms.

CLAUDE.md

@@ -12,7 +12,6 @@ Read and follow the CONTRIBUTING.md file in this repository for all code style c
 - Use descriptive names for variables and closure parameters. Single letters are permitted only in these cases: (1) conventional names like `n` for count or `f` for formatter; (2) comparison closures like `|a, b|`; (3) trivial single-expression closures; (4) fold accumulators; (5) index variables `i`/`j`/`k` in short closures or index-based loops; and (6) test fixtures with identical roles. Single letters are never permitted in multi-line functions or closures.
 - Use `pipe-trait` to chain through unary functions such as constructors, `Some`, `Ok`, and free functions. Use it to flatten nested calls and to continue method chains. Do not use it for simple standalone calls; prefer `foo(value)` over `value.pipe(foo)`.
 - Prefer `where` clauses when a type has multiple trait bounds.
-- Derive order: standard traits, then comparison traits, then `Hash`, then `derive_more`, then feature-gated derives.
 - For error types, only derive `Display` and `Error` from `derive_more` when each is actually needed. Not all displayable types are errors.
 - Minimize `unwrap()` in non-test code. Use proper error handling instead.
 - Prefer `#[cfg_attr(..., ignore = "reason")]` over `#[cfg(...)]` when skipping tests. Use `#[cfg]` on tests only when the code cannot compile under the condition, such as when it references types or functions that do not exist on other platforms.

CONTRIBUTING.md

@@ -71,16 +71,12 @@ pub use event::Event;
 
 ### Derive Macro Ordering
 
-When deriving multiple traits, use this order and split across multiple `#[derive(...)]` lines for readability:
+The order of trait names within each `#[derive(...)]` attribute is enforced automatically by the `perfectionist::derive_ordering` rule, configured for the `prefix_then_alphabetical` style. The configured `prefix` in `dylint.toml` lists the trait families in their project-preferred order: `Debug`, formatting / error derives (`Display`, `Error`), defaults (`Default`, `SmartDefault`), `Clone` / `Copy`, comparison and `Hash`, reference wrappers (`AsRef`, `AsMut`, `Deref`, `DerefMut`), conversions (`From`, `Into`, `TryFrom`, `TryInto`, `FromStr`), iteration, arithmetic operator pairs and folds, and integer-format derives. Any trait that is not in the `prefix` (project-specific derives such as `Setters` and `Parser`) falls in ASCII-case-insensitive alphabetical order after the prefix entries.
 
-1. **Standard traits:** `Debug`, `Default`, `Clone`, `Copy`
-2. **Comparison traits:** `PartialEq`, `Eq`, `PartialOrd`, `Ord`
-3. **Hash**
-4. **`derive_more` traits:** `Display`, `From`, `Into`, `Add`, `AddAssign`, etc.
-5. **Feature-gated derives** on a separate `#[cfg_attr(...)]` line
+The remaining conventions are not enforced by the rule and must be applied by hand. When a type derives many traits, split them across multiple `#[derive(...)]` lines for readability, and place feature-gated derives on a separate `#[cfg_attr(...)]` line.
 
 ```rust
-#[derive(Debug, Default, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+#[derive(Debug, Display, Default, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
 #[derive(From, Into, Add, AddAssign, Sub, SubAssign, Sum)]
 #[cfg_attr(feature = "json", derive(Deserialize, Serialize))]
 pub struct Bytes(u64);

Cargo.toml

@@ -88,6 +88,9 @@ terminal_size = "0.4.4"
 text-block-macros = "0.2.0"
 zero-copy-pads = "0.2.0"
 
+[lints.rust]
+unexpected_cfgs = { level = "warn", check-cfg = ['cfg(dylint_lib, values("perfectionist"))'] }
+
 [dev-dependencies]
 build-fs-tree = "0.8.1"
 command-extra = "1.0.0"

dylint.toml

@@ -1,4 +1,27 @@
 [workspace.metadata.dylint]
 libraries = [
-    { git = "https://github.com/KSXGitHub/perfectionist", tag = "0.0.0-rc.7" },
+    { git = "https://github.com/KSXGitHub/perfectionist", rev = "892533129e44ef48f7be468a9804ff36325f70fa" },
 ]
+
+["perfectionist::derive_ordering"]
+style = "prefix_then_alphabetical"
+prefix = [
+    "Debug", "Display", "Error",
+    "Default", "SmartDefault",
+    "Clone", "Copy",
+    "PartialEq", "Eq", "PartialOrd", "Ord",
+    "Hash",
+    "AsRef", "AsMut", "Deref", "DerefMut",
+    "From", "Into", "TryFrom", "TryInto", "FromStr",
+    "IntoIterator",
+    "Add", "AddAssign", "Sub", "SubAssign", "Mul", "MulAssign", "Div", "DivAssign",
+    "Sum", "Product",
+    "LowerHex", "UpperHex", "Octal",
+]
+
+["perfectionist::macro_argument_binding"]
+deny_extra = ["debug_assert_op", "debug_assert_op_expr"]
+allow_extra = ["bump", "link", "symlink", "test_case", "visualize"]
+
+["perfectionist::single_letter_closure_param"]
+comparison_methods = ["sort_by", "sort_unstable_by", "sort_by_key", "sort_unstable_by_key", "min_by", "max_by", "min_by_key", "max_by_key", "binary_search_by", "binary_search_by_key", "cmp_by", "partial_cmp_by", "eq_by", "fold", "sort_reflection_by", "into_sorted_by"]

src/app/overlapping_arguments.rs

@@ -14,7 +14,7 @@ pub trait Api {
     type RealPathError;
     fn canonicalize(path: &Self::Argument) -> Result<Self::RealPath, Self::RealPathError>;
     fn is_real_dir(path: &Self::Argument) -> bool;
-    fn starts_with(a: &Self::RealPath, b: &Self::RealPath) -> bool;
+    fn starts_with(path: &Self::RealPath, prefix: &Self::RealPath) -> bool;
 }
 
 /// Implementation of [`Api`] that interacts with the real system.
@@ -36,8 +36,8 @@ impl Api for RealApi {
     }
 
     #[inline]
-    fn starts_with(a: &Self::RealPath, b: &Self::RealPath) -> bool {
-        a.starts_with(b)
+    fn starts_with(path: &Self::RealPath, prefix: &Self::RealPath) -> bool {
+        path.starts_with(prefix)
     }
 }
 

src/app/overlapping_arguments/test_remove_overlapping_paths.rs

@@ -64,8 +64,8 @@ impl Api for MockedApi {
             .all(|(link, _)| PathBuf::from(link).normalize() != path)
     }
 
-    fn starts_with(a: &Self::RealPath, b: &Self::RealPath) -> bool {
-        a.starts_with(b)
+    fn starts_with(path: &Self::RealPath, prefix: &Self::RealPath) -> bool {
+        path.starts_with(prefix)
     }
 }
 

src/args.rs

@@ -1,3 +1,11 @@
+#![cfg_attr(
+    dylint_lib = "perfectionist",
+    allow(
+        perfectionist::single_letter_let_binding,
+        reason = "the `let s` bindings flagged by this lint originate in `clap_derive` macro expansion of `default_value_t` and are outside our control",
+    )
+)]
+
 pub mod depth;
 pub mod fraction;
 pub mod quantity;
@@ -17,7 +25,7 @@ use terminal_size::{Width, terminal_size};
 use text_block_macros::text_block;
 
 /// The CLI arguments.
-#[derive(Debug, SmartDefault, Setters, Clone, Parser)]
+#[derive(Debug, SmartDefault, Clone, Parser, Setters)]
 #[clap(
     name = "pdu",
 

src/args/depth.rs

@@ -7,7 +7,7 @@ use std::{
 const INFINITE: &str = "inf";
 
 /// Maximum depth of the tree.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Display)]
+#[derive(Debug, Display, Clone, Copy, PartialEq, Eq)]
 pub enum Depth {
     #[display("{INFINITE}")]
     Infinite,
@@ -25,7 +25,7 @@ impl Depth {
 }
 
 /// Error that occurs when parsing a string as [`Depth`].
-#[derive(Debug, Display, Clone, PartialEq, Eq, Error)]
+#[derive(Debug, Display, Error, Clone, PartialEq, Eq)]
 #[non_exhaustive]
 pub enum FromStrError {
     #[display("Value is neither {INFINITE:?} nor a positive integer: {_0}")]

src/args/fraction.rs

@@ -6,11 +6,18 @@ use std::{
 };
 
 /// Floating-point value that is greater than or equal to 0 and less than 1.
-#[derive(Debug, Default, Clone, Copy, PartialEq, PartialOrd, AsRef, Deref, Display, Into)]
+#[derive(Debug, Display, Default, Clone, Copy, PartialEq, PartialOrd, AsRef, Deref, Into)]
 pub struct Fraction(f32);
 
 /// Error that occurs when calling [`Fraction::new`].
-#[derive(Debug, Display, Clone, Copy, PartialEq, Eq, Error)]
+#[derive(Debug, Display, Error, Clone, Copy, PartialEq, Eq)]
+#[cfg_attr(
+    dylint_lib = "perfectionist",
+    expect(
+        perfectionist::non_exhaustive_error,
+        reason = "this error type is explicitly exhaustive: `Fraction::new` can only fail in the two ways enumerated below, and any future failure mode would be a `Fraction::new` API change worth a SemVer-major bump",
+    )
+)]
 pub enum ConversionError {
     /// Provided value is greater than or equal to 1.
     #[display("greater than or equal to 1")]
@@ -42,7 +49,14 @@ impl TryFrom<f32> for Fraction {
 }
 
 /// Error that occurs when parsing a string as [`Fraction`].
-#[derive(Debug, Display, Clone, PartialEq, Eq, Error)]
+#[derive(Debug, Display, Error, Clone, PartialEq, Eq)]
+#[cfg_attr(
+    dylint_lib = "perfectionist",
+    expect(
+        perfectionist::non_exhaustive_error,
+        reason = "this error type is explicitly exhaustive: `Fraction::from_str` can only fail in the two ways enumerated below, and any future failure mode would be a `Fraction::from_str` API change worth a SemVer-major bump",
+    )
+)]
 pub enum FromStrError {
     ParseFloatError(ParseFloatError),
     Conversion(ConversionError),

src/args/threads.rs

@@ -8,7 +8,7 @@ const AUTO: &str = "auto";
 const MAX: &str = "max";
 
 /// Number of rayon threads.
-#[derive(Debug, Default, Clone, Copy, PartialEq, Eq, Display)]
+#[derive(Debug, Display, Default, Clone, Copy, PartialEq, Eq)]
 pub enum Threads {
     #[default]
     #[display("{AUTO}")]
@@ -19,7 +19,7 @@ pub enum Threads {
 }
 
 /// Error that occurs when parsing a string as [`Threads`].
-#[derive(Debug, Display, Clone, PartialEq, Eq, Error)]
+#[derive(Debug, Display, Error, Clone, PartialEq, Eq)]
 #[non_exhaustive]
 pub enum FromStrError {
     #[display("Value is neither {AUTO:?}, {MAX:?}, nor a number: {_0}")]

src/bytes_format/parsed_value.rs

@@ -1,7 +1,7 @@
-use derive_more::{Display, Error};
+use derive_more::Display;
 
 /// Return value of [`Formatter::parse_value`](super::Formatter::parse_value).
-#[derive(Debug, Display, Clone, Copy, Error)]
+#[derive(Debug, Display, Clone, Copy)]
 pub enum ParsedValue {
     /// When input value is less than `scale_base`.
     #[display("{value}   ")]

src/device.rs

@@ -23,7 +23,7 @@ impl DeviceBoundary {
 
 /// The device number of a filesystem.
 #[derive(
-    Debug, Display, LowerHex, UpperHex, Octal, Clone, Copy, PartialEq, Eq, Hash, From, Into,
+    Debug, Display, Clone, Copy, PartialEq, Eq, Hash, From, Into, LowerHex, UpperHex, Octal,
 )]
 #[cfg_attr(feature = "json", derive(Deserialize, Serialize))]
 pub struct DeviceNumber(u64);

src/hardlink/hardlink_list.rs

@@ -21,7 +21,7 @@ use pipe_trait::Pipe;
 use std::path::Path;
 
 /// Internal key used to uniquely identify an inode across all filesystems.
-#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 struct InodeKey {
     /// Inode number within the device.
     ino: InodeNumber,

src/hardlink/hardlink_list/summary.rs

@@ -11,7 +11,7 @@ use std::{
 use serde::{Deserialize, Serialize};
 
 /// Summary from [`HardlinkList`] or [`Reflection`].
-#[derive(Debug, Default, Setters, Clone, Copy, PartialEq, Eq, Add, AddAssign, Sum)]
+#[derive(Debug, Default, Clone, Copy, PartialEq, Eq, Add, AddAssign, Sum, Setters)]
 #[cfg_attr(feature = "json", derive(Deserialize, Serialize))]
 #[setters(prefix = "with_")]
 #[non_exhaustive]

src/inode.rs

@@ -5,7 +5,7 @@ use serde::{Deserialize, Serialize};
 
 /// The inode number of a file or directory.
 #[derive(
-    Debug, Display, LowerHex, UpperHex, Octal, Clone, Copy, PartialEq, Eq, Hash, From, Into,
+    Debug, Display, Clone, Copy, PartialEq, Eq, Hash, From, Into, LowerHex, UpperHex, Octal,
 )]
 #[cfg_attr(feature = "json", derive(Deserialize, Serialize))]
 pub struct InodeNumber(u64);

src/json_data/binary_version.rs

@@ -7,7 +7,7 @@ use serde::{Deserialize, Serialize};
 pub const CURRENT_VERSION: &str = env!("CARGO_PKG_VERSION");
 
 /// Version of the `pdu` program that created the input JSON.
-#[derive(Debug, Clone, PartialEq, Eq, AsMut, AsRef, From, FromStr, Into)]
+#[derive(Debug, Clone, PartialEq, Eq, AsRef, AsMut, From, Into, FromStr)]
 #[cfg_attr(feature = "json", derive(Deserialize, Serialize))]
 pub struct BinaryVersion(String);
 

src/lib.rs

@@ -4,6 +4,12 @@
 //! [`tree_builder::TreeBuilder`], [`data_tree::DataTree`], or [`visualizer::Visualizer`].
 
 #![deny(warnings)]
+#![cfg_attr(dylint_lib = "perfectionist", feature(register_tool))]
+#![cfg_attr(dylint_lib = "perfectionist", register_tool(perfectionist))]
+#![cfg_attr(
+    dylint_lib = "perfectionist",
+    deny(perfectionist::non_exhaustive_error)
+)]
 
 #[cfg(feature = "json")]
 pub use serde;

src/os_string_display.rs

@@ -20,8 +20,8 @@ use serde::{Deserialize, Serialize};
     Eq,
     PartialOrd,
     Ord,
-    AsMut,
     AsRef,
+    AsMut,
     Deref,
     DerefMut,
     From,

src/reporter/error_report/text_report.rs

@@ -42,6 +42,6 @@ fn test() {
         ),
     };
     let actual = TextReport(report).to_string();
-    let expected = "[error] read_dir \"path/to/a/directory\": Something goes wrong (os error 420)";
+    let expected = r#"[error] read_dir "path/to/a/directory": Something goes wrong (os error 420)"#;
     assert_eq!(actual, expected);
 }

src/reporter/progress_and_error_reporter.rs

@@ -47,7 +47,7 @@ where
         ReportProgress: Fn(ProgressReport<Size>) + Send + Sync + 'static,
     {
         let progress = Arc::new(ProgressReportState::default());
-        let progress_thread = progress.clone();
+        let progress_thread = Arc::clone(&progress);
         let progress_reporter_handle = spawn(move || {
             loop {
                 sleep(progress_report_interval);

src/reporter/progress_report.rs

@@ -3,7 +3,7 @@ use derive_setters::Setters;
 use std::fmt::Write;
 
 /// Scan progress.
-#[derive(Debug, Default, Setters, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+#[derive(Debug, Default, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Setters)]
 #[setters(prefix = "with_")]
 pub struct ProgressReport<Size: size::Size> {
     /// Number of scanned items.

src/usage_md.rs

@@ -85,7 +85,7 @@ fn render_argument(out: &mut String, arg: &Arg) {
         .unwrap_or_else(|| arg.get_id().as_str());
     let is_multiple = arg
         .get_num_args()
-        .map(|r| r.max_values() > 1)
+        .map(|range| range.max_values() > 1)
         .unwrap_or(false);
     let display_name = if arg.is_required_set() {
         if is_multiple {

src/visualizer/proportion_bar.rs

@@ -4,20 +4,14 @@ use fmt_iter::repeat;
 use std::fmt::{Display, Error, Formatter};
 
 /// Block of proportion bar.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, AsRef, Deref, Display, Into)]
+#[derive(Debug, Display, Clone, Copy, PartialEq, Eq, AsRef, Deref, Into)]
 pub struct ProportionBarBlock(char);
 
-macro_rules! make_const {
-    ($name:ident = $content:literal) => {
-        pub const $name: ProportionBarBlock = ProportionBarBlock($content);
-    };
-}
-
-make_const!(LEVEL0_BLOCK = '█');
-make_const!(LEVEL1_BLOCK = '▓');
-make_const!(LEVEL2_BLOCK = '▒');
-make_const!(LEVEL3_BLOCK = '░');
-make_const!(LEVEL4_BLOCK = ' ');
+pub const LEVEL0_BLOCK: ProportionBarBlock = ProportionBarBlock('█');
+pub const LEVEL1_BLOCK: ProportionBarBlock = ProportionBarBlock('▓');
+pub const LEVEL2_BLOCK: ProportionBarBlock = ProportionBarBlock('▒');
+pub const LEVEL3_BLOCK: ProportionBarBlock = ProportionBarBlock('░');
+pub const LEVEL4_BLOCK: ProportionBarBlock = ProportionBarBlock(' ');
 
 /// Proportion bar.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, From, Into)]

src/visualizer/tree.rs

@@ -18,7 +18,7 @@ pub struct TreeSkeletalComponent {
 }
 
 /// String made by calling [`TreeSkeletalComponent::visualize`](TreeSkeletalComponent).
-#[derive(Debug, Clone, Copy, PartialEq, Eq, AsRef, Deref, Display, Into)]
+#[derive(Debug, Display, Clone, Copy, PartialEq, Eq, AsRef, Deref, Into)]
 pub struct TreeSkeletalComponentVisualization(&'static str);
 
 impl TreeSkeletalComponent {

template/ai-instructions/shared.md

@@ -12,7 +12,6 @@ Read and follow the CONTRIBUTING.md file in this repository for all code style c
 - Use descriptive names for variables and closure parameters. Single letters are permitted only in these cases: (1) conventional names like `n` for count or `f` for formatter; (2) comparison closures like `|a, b|`; (3) trivial single-expression closures; (4) fold accumulators; (5) index variables `i`/`j`/`k` in short closures or index-based loops; and (6) test fixtures with identical roles. Single letters are never permitted in multi-line functions or closures.
 - Use `pipe-trait` to chain through unary functions such as constructors, `Some`, `Ok`, and free functions. Use it to flatten nested calls and to continue method chains. Do not use it for simple standalone calls; prefer `foo(value)` over `value.pipe(foo)`.
 - Prefer `where` clauses when a type has multiple trait bounds.
-- Derive order: standard traits, then comparison traits, then `Hash`, then `derive_more`, then feature-gated derives.
 - For error types, only derive `Display` and `Error` from `derive_more` when each is actually needed. Not all displayable types are errors.
 - Minimize `unwrap()` in non-test code. Use proper error handling instead.
 - Prefer `#[cfg_attr(..., ignore = "reason")]` over `#[cfg(...)]` when skipping tests. Use `#[cfg]` on tests only when the code cannot compile under the condition, such as when it references types or functions that do not exist on other platforms.

tests/_utils.rs

@@ -466,7 +466,7 @@ impl<'a> Default for CommandList<'a> {
     /// Initialize a list with one `pdu` command.
     fn default() -> Self {
         CommandRepresentation::default()
-            .pipe(|x| vec![x])
+            .pipe(|command| vec![command])
             .pipe(CommandList)
     }
 }

tests/cli_errors.rs

@@ -168,8 +168,8 @@ fn fs_errors() {
         .map(|line| line.trim_start_matches('\r'))
         .collect();
     let expected_stderr_lines = btreeset! {
-        "[error] read_dir \"./nested/0\": Permission denied (os error 13)",
-        "[error] read_dir \"./empty-dir\": Permission denied (os error 13)",
+        r#"[error] read_dir "./nested/0": Permission denied (os error 13)"#,
+        r#"[error] read_dir "./empty-dir": Permission denied (os error 13)"#,
     };
     assert_eq!(actual_stderr_lines, expected_stderr_lines);