Unify line size settings between ruff and the formatter

crates/flake8_to_ruff/src/black.rs

@@ -1,12 +1,13 @@
 //! Extract Black configuration settings from a pyproject.toml.
 
+use ruff::line_width::LineLength;
 use ruff::settings::types::PythonVersion;
 use serde::{Deserialize, Serialize};
 
 #[derive(Debug, PartialEq, Eq, Serialize, Deserialize, Default)]
 pub(crate) struct Black {
     #[serde(alias = "line-length", alias = "line_length")]
-    pub(crate) line_length: Option<usize>,
+    pub(crate) line_length: Option<LineLength>,
     #[serde(alias = "target-version", alias = "target_version")]
     pub(crate) target_version: Option<Vec<PythonVersion>>,
 }

crates/flake8_to_ruff/src/converter.rs

@@ -1,4 +1,5 @@
 use std::collections::{HashMap, HashSet};
+use std::str::FromStr;
 
 use itertools::Itertools;
 
@@ -119,10 +120,8 @@ pub(crate) fn convert(
                 "builtins" => {
                     options.builtins = Some(parser::parse_strings(value.as_ref()));
                 }
-                "max-line-length" | "max_line_length" => match value.parse::<usize>() {
-                    Ok(line_length) => {
-                        options.line_length = Some(LineLength::from(line_length));
-                    }
+                "max-line-length" | "max_line_length" => match LineLength::from_str(value) {
+                    Ok(line_length) => options.line_length = Some(line_length),
                     Err(e) => {
                         warn_user!("Unable to parse '{key}' property: {e}");
                     }
@@ -405,7 +404,7 @@ pub(crate) fn convert(
     // Extract any settings from the existing `pyproject.toml`.
     if let Some(black) = &external_config.black {
         if let Some(line_length) = &black.line_length {
-            options.line_length = Some(LineLength::from(*line_length));
+            options.line_length = Some(*line_length);
         }
 
         if let Some(target_version) = &black.target_version {
@@ -512,7 +511,7 @@ mod tests {
             Some(vec![]),
         );
         let expected = Pyproject::new(Options {
-            line_length: Some(LineLength::from(100)),
+            line_length: Some(LineLength::try_from(100).unwrap()),
             ..default_options([])
         });
         assert_eq!(actual, expected);
@@ -529,7 +528,7 @@ mod tests {
             Some(vec![]),
         );
         let expected = Pyproject::new(Options {
-            line_length: Some(LineLength::from(100)),
+            line_length: Some(LineLength::try_from(100).unwrap()),
             ..default_options([])
         });
         assert_eq!(actual, expected);

crates/ruff/src/checkers/physical_lines.rs

@@ -1,10 +1,9 @@
 //! Lint rules based on checking physical lines.
-use ruff_text_size::TextSize;
-
 use ruff_diagnostics::Diagnostic;
 use ruff_python_codegen::Stylist;
 use ruff_python_index::Indexer;
 use ruff_source_file::{Locator, UniversalNewlines};
+use ruff_text_size::TextSize;
 
 use crate::registry::Rule;
 use crate::rules::flake8_copyright::rules::missing_copyright_notice;
@@ -99,11 +98,10 @@ pub(crate) fn check_physical_lines(
 
 #[cfg(test)]
 mod tests {
-    use ruff_python_parser::lexer::lex;
-    use ruff_python_parser::Mode;
-
     use ruff_python_codegen::Stylist;
     use ruff_python_index::Indexer;
+    use ruff_python_parser::lexer::lex;
+    use ruff_python_parser::Mode;
     use ruff_source_file::Locator;
 
     use crate::line_width::LineLength;
@@ -132,7 +130,7 @@ mod tests {
                 },
             )
         };
-        let line_length = LineLength::from(8);
+        let line_length = LineLength::try_from(8).unwrap();
         assert_eq!(check_with_max_line_length(line_length), vec![]);
         assert_eq!(check_with_max_line_length(line_length), vec![]);
     }

crates/ruff/src/line_width.rs

@@ -1,30 +1,111 @@
+use ruff_cache::{CacheKey, CacheKeyHasher};
 use serde::{Deserialize, Serialize};
-use std::num::NonZeroU8;
+use std::error::Error;
+use std::hash::Hasher;
+use std::num::{NonZeroU16, NonZeroU8, ParseIntError};
+use std::str::FromStr;
 use unicode_width::UnicodeWidthChar;
 
 use ruff_macros::CacheKey;
 
 /// The length of a line of text that is considered too long.
-#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize, CacheKey)]
+///
+/// The allowed range of values is 1..=320
+#[derive(Clone, Copy, Debug, Eq, PartialEq, serde::Serialize, serde::Deserialize)]
 #[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
-pub struct LineLength(usize);
+pub struct LineLength(NonZeroU16);
+
+impl LineLength {
+    /// Maximum allowed value for a valid [`LineLength`]
+    pub const MAX: u16 = 320;
+
+    /// Return the numeric value for this [`LineLength`]
+    pub fn value(&self) -> u16 {
+        self.0.get()
+    }
+}
 
 impl Default for LineLength {
-    /// The default line length.
     fn default() -> Self {
-        Self(88)
+        Self(NonZeroU16::new(88).unwrap())
     }
 }
 
-impl LineLength {
-    pub const fn get(&self) -> usize {
-        self.0
+impl CacheKey for LineLength {
+    fn cache_key(&self, state: &mut CacheKeyHasher) {
+        state.write_u16(self.0.get());
+    }
+}
+
+/// Error type returned when parsing a [`LineLength`] from a string fails
+pub enum ParseLineWidthError {
+    /// The string could not be parsed as a valid [u16]
+    ParseError(ParseIntError),
+    /// The [u16] value of the string is not a valid [LineLength]
+    TryFromIntError(LineLengthFromIntError),
+}
+
+impl std::fmt::Debug for ParseLineWidthError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        std::fmt::Display::fmt(self, f)
+    }
+}
+
+impl std::fmt::Display for ParseLineWidthError {
+    fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            ParseLineWidthError::ParseError(err) => std::fmt::Display::fmt(err, fmt),
+            ParseLineWidthError::TryFromIntError(err) => std::fmt::Display::fmt(err, fmt),
+        }
+    }
+}
+
+impl Error for ParseLineWidthError {}
+
+impl FromStr for LineLength {
+    type Err = ParseLineWidthError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let value = u16::from_str(s).map_err(ParseLineWidthError::ParseError)?;
+        let value = Self::try_from(value).map_err(ParseLineWidthError::TryFromIntError)?;
+        Ok(value)
+    }
+}
+
+/// Error type returned when converting a u16 to a [`LineLength`] fails
+#[derive(Clone, Copy, Debug)]
+pub struct LineLengthFromIntError(pub u16);
+
+impl TryFrom<u16> for LineLength {
+    type Error = LineLengthFromIntError;
+
+    fn try_from(value: u16) -> Result<Self, Self::Error> {
+        match NonZeroU16::try_from(value) {
+            Ok(value) if value.get() <= Self::MAX => Ok(LineLength(value)),
+            Ok(_) | Err(_) => Err(LineLengthFromIntError(value)),
+        }
+    }
+}
+
+impl std::fmt::Display for LineLengthFromIntError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        writeln!(
+            f,
+            "The line width must be a value between 1 and {}.",
+            LineLength::MAX
+        )
+    }
+}
+
+impl From<LineLength> for u16 {
+    fn from(value: LineLength) -> Self {
+        value.0.get()
     }
 }
 
-impl From<usize> for LineLength {
-    fn from(value: usize) -> Self {
-        Self(value)
+impl From<LineLength> for NonZeroU16 {
+    fn from(value: LineLength) -> Self {
+        value.0
     }
 }
 
@@ -33,7 +114,7 @@ impl From<usize> for LineLength {
 /// This is used to determine if a line is too long.
 /// It should be compared to a [`LineLength`].
 #[derive(Clone, Copy, Debug)]
-pub struct LineWidth {
+pub struct LineWidthBuilder {
     /// The width of the line.
     width: usize,
     /// The column of the line.
@@ -43,40 +124,40 @@ pub struct LineWidth {
     tab_size: TabSize,
 }
 
-impl Default for LineWidth {
+impl Default for LineWidthBuilder {
     fn default() -> Self {
         Self::new(TabSize::default())
     }
 }
 
-impl PartialEq for LineWidth {
+impl PartialEq for LineWidthBuilder {
     fn eq(&self, other: &Self) -> bool {
         self.width == other.width
     }
 }
 
-impl Eq for LineWidth {}
+impl Eq for LineWidthBuilder {}
 
-impl PartialOrd for LineWidth {
+impl PartialOrd for LineWidthBuilder {
     fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
         Some(self.cmp(other))
     }
 }
 
-impl Ord for LineWidth {
+impl Ord for LineWidthBuilder {
     fn cmp(&self, other: &Self) -> std::cmp::Ordering {
         self.width.cmp(&other.width)
     }
 }
 
-impl LineWidth {
+impl LineWidthBuilder {
     pub fn get(&self) -> usize {
         self.width
     }
 
     /// Creates a new `LineWidth` with the given tab size.
     pub fn new(tab_size: TabSize) -> Self {
-        LineWidth {
+        LineWidthBuilder {
             width: 0,
             column: 0,
             tab_size,
@@ -119,7 +200,7 @@ impl LineWidth {
 
     /// Adds the given width to the line width.
     /// Also adds the given width to the column.
-    /// It is generally better to use [`LineWidth::add_str`] or [`LineWidth::add_char`].
+    /// It is generally better to use [`LineWidthBuilder::add_str`] or [`LineWidthBuilder::add_char`].
     /// The width and column should be the same for the corresponding text.
     /// Currently, this is only used to add spaces.
     #[must_use]
@@ -130,15 +211,15 @@ impl LineWidth {
     }
 }
 
-impl PartialEq<LineLength> for LineWidth {
+impl PartialEq<LineLength> for LineWidthBuilder {
     fn eq(&self, other: &LineLength) -> bool {
-        self.width == other.0
+        self.width == (other.value() as usize)
     }
 }
 
-impl PartialOrd<LineLength> for LineWidth {
+impl PartialOrd<LineLength> for LineWidthBuilder {
     fn partial_cmp(&self, other: &LineLength) -> Option<std::cmp::Ordering> {
-        self.width.partial_cmp(&other.0)
+        self.width.partial_cmp(&(other.value() as usize))
     }
 }
 

crates/ruff/src/message/text.rs

@@ -12,7 +12,7 @@ use ruff_text_size::{Ranged, TextRange, TextSize};
 
 use crate::fs::relativize_path;
 use crate::jupyter::{Notebook, NotebookIndex};
-use crate::line_width::{LineWidth, TabSize};
+use crate::line_width::{LineWidthBuilder, TabSize};
 use crate::message::diff::Diff;
 use crate::message::{Emitter, EmitterContext, Message};
 use crate::registry::AsRule;
@@ -292,7 +292,7 @@ fn replace_whitespace(source: &str, annotation_range: TextRange) -> SourceCode {
     let mut result = String::new();
     let mut last_end = 0;
     let mut range = annotation_range;
-    let mut line_width = LineWidth::new(TabSize::default());
+    let mut line_width = LineWidthBuilder::new(TabSize::default());
 
     for (index, c) in source.char_indices() {
         let old_width = line_width.get();

crates/ruff/src/rules/flake8_simplify/rules/ast_if.rs

@@ -15,7 +15,7 @@ use ruff_python_trivia::{SimpleTokenKind, SimpleTokenizer};
 use ruff_source_file::{Locator, UniversalNewlines};
 
 use crate::checkers::ast::Checker;
-use crate::line_width::LineWidth;
+use crate::line_width::LineWidthBuilder;
 use crate::registry::AsRule;
 use crate::rules::flake8_simplify::rules::fix_if;
 
@@ -414,7 +414,7 @@ pub(crate) fn nested_if_statements(
                         .unwrap_or_default()
                         .universal_newlines()
                         .all(|line| {
-                            LineWidth::new(checker.settings.tab_size).add_str(&line)
+                            LineWidthBuilder::new(checker.settings.tab_size).add_str(&line)
                                 <= checker.settings.line_length
                         })
                     {
@@ -660,7 +660,7 @@ pub(crate) fn use_ternary_operator(checker: &mut Checker, stmt: &Stmt) {
 
     // Don't flag if the resulting expression would exceed the maximum line length.
     let line_start = checker.locator().line_start(stmt.start());
-    if LineWidth::new(checker.settings.tab_size)
+    if LineWidthBuilder::new(checker.settings.tab_size)
         .add_str(&checker.locator().contents()[TextRange::new(line_start, stmt.start())])
         .add_str(&contents)
         > checker.settings.line_length
@@ -964,7 +964,7 @@ pub(crate) fn use_dict_get_with_default(checker: &mut Checker, stmt_if: &ast::St
 
     // Don't flag if the resulting expression would exceed the maximum line length.
     let line_start = checker.locator().line_start(stmt_if.start());
-    if LineWidth::new(checker.settings.tab_size)
+    if LineWidthBuilder::new(checker.settings.tab_size)
         .add_str(&checker.locator().contents()[TextRange::new(line_start, stmt_if.start())])
         .add_str(&contents)
         > checker.settings.line_length

crates/ruff/src/rules/flake8_simplify/rules/ast_with.rs

@@ -9,7 +9,7 @@ use ruff_source_file::UniversalNewlines;
 use ruff_text_size::{Ranged, TextRange};
 
 use crate::checkers::ast::Checker;
-use crate::line_width::LineWidth;
+use crate::line_width::LineWidthBuilder;
 use crate::registry::AsRule;
 
 use super::fix_with;
@@ -142,7 +142,7 @@ pub(crate) fn multiple_with_statements(
                             .unwrap_or_default()
                             .universal_newlines()
                             .all(|line| {
-                                LineWidth::new(checker.settings.tab_size).add_str(&line)
+                                LineWidthBuilder::new(checker.settings.tab_size).add_str(&line)
                                     <= checker.settings.line_length
                             })
                         {