Unify line size settings between ruff and the formatter (#6873)

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);
-
-impl Default for LineLength {
-    /// The default line length.
-    fn default() -> Self {
-        Self(88)
-    }
-}
+pub struct LineLength(NonZeroU16);
 
 impl LineLength {
-    pub const fn get(&self) -> usize {
-        self.0
+    /// 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 From<usize> for LineLength {
-    fn from(value: usize) -> Self {
-        Self(value)
+impl Default for LineLength {
+    fn default() -> Self {
+        Self(NonZeroU16::new(88).unwrap())
+    }
+}
+
+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<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))
     }
 }