Fix \r and \r\n handling in t- and f-string debug texts (#18673)

.gitattributes

@@ -5,6 +5,9 @@ crates/ruff_linter/resources/test/fixtures/pycodestyle/W605_1.py text eol=crlf
 crates/ruff_linter/resources/test/fixtures/pycodestyle/W391_2.py text eol=crlf
 crates/ruff_linter/resources/test/fixtures/pycodestyle/W391_3.py text eol=crlf
 
+crates/ruff_python_formatter/resources/test/fixtures/ruff/f-string-carriage-return-newline.py text eol=crlf
+crates/ruff_python_formatter/tests/snapshots/format@f-string-carriage-return-newline.py.snap text eol=crlf
+
 crates/ruff_python_formatter/resources/test/fixtures/ruff/docstring_code_examples_crlf.py text eol=crlf
 crates/ruff_python_formatter/tests/snapshots/format@docstring_code_examples_crlf.py.snap text eol=crlf
 

crates/ruff_python_formatter/resources/test/fixtures/ruff/.editorconfig

@@ -8,4 +8,8 @@ ij_formatter_enabled = false
 
 [docstring_tab_indentation.py]
 generated_code = true
-ij_formatter_enabled = false
+ij_formatter_enabled = false
+
+[f-string-carriage-return-newline.py]
+generated_code = true
+ij_formatter_enabled = false

crates/ruff_python_formatter/resources/test/fixtures/ruff/f-string-carriage-return-newline.py

@@ -0,0 +1,8 @@
+# Regression test for https://github.com/astral-sh/ruff/issues/18667
+f"{
+1=
+}"
+
+t"{
+1=
+}"

crates/ruff_python_formatter/src/other/interpolated_string_element.rs

@@ -1,6 +1,6 @@
 use std::borrow::Cow;
 
-use ruff_formatter::{Buffer, RemoveSoftLinesBuffer, format_args, write};
+use ruff_formatter::{Buffer, FormatOptions as _, RemoveSoftLinesBuffer, format_args, write};
 use ruff_python_ast::{
     AnyStringFlags, ConversionFlag, Expr, InterpolatedElement, InterpolatedStringElement,
     InterpolatedStringLiteralElement, StringFlags,
@@ -178,9 +178,9 @@ impl Format<PyFormatContext<'_>> for FormatInterpolatedElement<'_> {
             write!(
                 f,
                 [
-                    text(&debug_text.leading),
+                    NormalizedDebugText(&debug_text.leading),
                     verbatim_text(&**expression),
-                    text(&debug_text.trailing),
+                    NormalizedDebugText(&debug_text.trailing),
                 ]
             )?;
 
@@ -316,3 +316,18 @@ fn needs_bracket_spacing(expr: &Expr, context: &PyFormatContext) -> bool {
         Expr::Dict(_) | Expr::DictComp(_) | Expr::Set(_) | Expr::SetComp(_)
     )
 }
+
+struct NormalizedDebugText<'a>(&'a str);
+
+impl Format<PyFormatContext<'_>> for NormalizedDebugText<'_> {
+    fn fmt(&self, f: &mut PyFormatter) -> FormatResult<()> {
+        let normalized = normalize_newlines(self.0, ['\r']);
+
+        f.write_element(FormatElement::Text {
+            text_width: TextWidth::from_text(&normalized, f.options().indent_width()),
+            text: normalized.into_owned().into_boxed_str(),
+        });
+
+        Ok(())
+    }
+}

crates/ruff_python_formatter/tests/normalizer.rs

@@ -196,6 +196,24 @@ impl Transformer for Normalizer {
         transformer::walk_expr(self, expr);
     }
 
+    fn visit_interpolated_string_element(
+        &self,
+        interpolated_string_element: &mut InterpolatedStringElement,
+    ) {
+        let InterpolatedStringElement::Interpolation(interpolation) = interpolated_string_element
+        else {
+            return;
+        };
+
+        let Some(debug) = &mut interpolation.debug_text else {
+            return;
+        };
+
+        // Changing the newlines to the configured newline is okay because Python normalizes all newlines to `\n`
+        debug.leading = debug.leading.replace("\r\n", "\n").replace('\r', "\n");
+        debug.trailing = debug.trailing.replace("\r\n", "\n").replace('\r', "\n");
+    }
+
     fn visit_string_literal(&self, string_literal: &mut ast::StringLiteral) {
         static STRIP_DOC_TESTS: LazyLock<Regex> = LazyLock::new(|| {
             Regex::new(

crates/ruff_python_formatter/tests/snapshots/format@f-string-carriage-return-newline.py.snap

@@ -0,0 +1,27 @@
+---
+source: crates/ruff_python_formatter/tests/fixtures.rs
+input_file: crates/ruff_python_formatter/resources/test/fixtures/ruff/f-string-carriage-return-newline.py
+---
+## Input
+```python
+# Regression test for https://github.com/astral-sh/ruff/issues/18667
+f"{
+1=
+}"
+
+t"{
+1=
+}"
+```
+
+## Output
+```python
+# Regression test for https://github.com/astral-sh/ruff/issues/18667
+f"{
+1=
+}"
+
+t"{
+1=
+}"
+```