Add tab width option (#6848)

crates/ruff_formatter/src/printer/mod.rs

@@ -732,7 +732,7 @@ impl<'a> Printer<'a> {
 
             #[allow(clippy::cast_possible_truncation)]
             let char_width = if char == '\t' {
-                u32::from(self.options.tab_width)
+                self.options.tab_width.value()
             } else {
                 // SAFETY: A u32 is sufficient to represent the width of a file <= 4GB
                 char.width().unwrap_or(0) as u32
@@ -1283,13 +1283,12 @@ impl<'a, 'print> FitsMeasurer<'a, 'print> {
 
     fn fits_text(&mut self, text: &str, args: PrintElementArgs) -> Fits {
         let indent = std::mem::take(&mut self.state.pending_indent);
-        self.state.line_width += u32::from(indent.level())
-            * u32::from(self.options().indent_width())
-            + u32::from(indent.align());
+        self.state.line_width +=
+            u32::from(indent.level()) * self.options().indent_width() + u32::from(indent.align());
 
         for c in text.chars() {
             let char_width = match c {
-                '\t' => u32::from(self.options().tab_width),
+                '\t' => self.options().tab_width.value(),
                 '\n' => {
                     if self.must_be_flat {
                         return Fits::No;
@@ -1428,7 +1427,9 @@ mod tests {
     use crate::prelude::*;
     use crate::printer::{LineEnding, PrintWidth, Printer, PrinterOptions};
     use crate::source_code::SourceCode;
-    use crate::{format_args, write, Document, FormatState, IndentStyle, Printed, VecBuffer};
+    use crate::{
+        format_args, write, Document, FormatState, IndentStyle, Printed, TabWidth, VecBuffer,
+    };
 
     fn format(root: &dyn Format<SimpleFormatContext>) -> Printed {
         format_with_options(
@@ -1578,7 +1579,7 @@ two lines`,
     fn it_use_the_indent_character_specified_in_the_options() {
         let options = PrinterOptions {
             indent_style: IndentStyle::Tab,
-            tab_width: 4,
+            tab_width: TabWidth::try_from(4).unwrap(),
             print_width: PrintWidth::new(19),
             ..PrinterOptions::default()
         };

crates/ruff_formatter/src/printer/printer_options/mod.rs

@@ -1,10 +1,10 @@
-use crate::{FormatOptions, IndentStyle, LineWidth};
+use crate::{FormatOptions, IndentStyle, LineWidth, TabWidth};
 
 /// Options that affect how the [`crate::Printer`] prints the format tokens
-#[derive(Clone, Debug, Eq, PartialEq)]
+#[derive(Clone, Debug, Eq, PartialEq, Default)]
 pub struct PrinterOptions {
     /// Width of a single tab character (does it equal 2, 4, ... spaces?)
-    pub tab_width: u8,
+    pub tab_width: TabWidth,
 
     /// What's the max width of a line. Defaults to 80
     pub print_width: PrintWidth,
@@ -74,23 +74,31 @@ impl PrinterOptions {
         self
     }
 
+    #[must_use]
+    pub fn with_tab_width(mut self, width: TabWidth) -> Self {
+        self.tab_width = width;
+
+        self
+    }
+
     pub(crate) fn indent_style(&self) -> IndentStyle {
         self.indent_style
     }
 
     /// Width of an indent in characters.
-    pub(super) const fn indent_width(&self) -> u8 {
+    pub(super) const fn indent_width(&self) -> u32 {
         match self.indent_style {
-            IndentStyle::Tab => self.tab_width,
-            IndentStyle::Space(count) => count,
+            IndentStyle::Tab => self.tab_width.value(),
+            IndentStyle::Space(count) => count as u32,
         }
     }
 }
 
 #[allow(dead_code)]
-#[derive(Clone, Debug, Eq, PartialEq)]
+#[derive(Clone, Debug, Eq, PartialEq, Default)]
 pub enum LineEnding {
     ///  Line Feed only (\n), common on Linux and macOS as well as inside git repos
+    #[default]
     LineFeed,
 
     /// Carriage Return + Line Feed characters (\r\n), common on Windows
@@ -110,14 +118,3 @@ impl LineEnding {
         }
     }
 }
-
-impl Default for PrinterOptions {
-    fn default() -> Self {
-        PrinterOptions {
-            tab_width: 2,
-            print_width: PrintWidth::default(),
-            indent_style: IndentStyle::default(),
-            line_ending: LineEnding::LineFeed,
-        }
-    }
-}