Ignore quote escapes in expression part of f-string

crates/ruff_python_formatter/src/expression/string.rs

@@ -138,16 +138,8 @@ impl<'a> FormatString<'a> {
 
 impl<'a> Format<PyFormatContext<'_>> for FormatString<'a> {
     fn fmt(&self, f: &mut PyFormatter) -> FormatResult<()> {
-        // TODO(dhruvmanila): With PEP 701, comments can be inside f-strings.
-        // This is to mark all of those comments as formatted but we need to
-        // figure out how to handle them.
-        if matches!(self.string, AnyString::FString(_)) {
-            f.context()
-                .comments()
-                .mark_verbatim_node_comments_formatted(self.string.into());
-        }
         let locator = f.context().locator();
-        match self.layout {
+        let result = match self.layout {
             StringLayout::Default => {
                 if self.string.is_implicit_concatenated() {
                     in_parentheses_only_group(&FormatStringContinuation::new(self.string)).fmt(f)
@@ -170,7 +162,18 @@ impl<'a> Format<PyFormatContext<'_>> for FormatString<'a> {
             StringLayout::ImplicitConcatenatedStringInBinaryLike => {
                 FormatStringContinuation::new(self.string).fmt(f)
             }
+        };
+        // TODO(dhruvmanila): With PEP 701, comments can be inside f-strings.
+        // This is to mark all of those comments as formatted but we need to
+        // figure out how to handle them. Note that this needs to be done only
+        // after the f-string is formatted, so only for all the non-formatted
+        // comments.
+        if matches!(self.string, AnyString::FString(_)) {
+            f.context()
+                .comments()
+                .mark_verbatim_node_comments_formatted(self.string.into());
         }
+        result
     }
 }
 
@@ -430,7 +433,7 @@ impl StringPart {
         let normalized = normalize_string(
             locator.slice(self.content_range),
             preferred_quotes,
-            self.prefix.is_raw_string(),
+            self.prefix,
         );
 
         NormalizedString {
@@ -523,6 +526,10 @@ impl StringPrefix {
     pub(super) const fn is_raw_string(self) -> bool {
         self.contains(StringPrefix::RAW) || self.contains(StringPrefix::RAW_UPPER)
     }
+
+    pub(super) const fn is_fstring(self) -> bool {
+        self.contains(StringPrefix::F_STRING)
+    }
 }
 
 impl Format<PyFormatContext<'_>> for StringPrefix {
@@ -760,7 +767,7 @@ impl Format<PyFormatContext<'_>> for StringQuotes {
 /// with the provided `style`.
 ///
 /// Returns the normalized string and whether it contains new lines.
-fn normalize_string(input: &str, quotes: StringQuotes, is_raw: bool) -> Cow<str> {
+fn normalize_string(input: &str, quotes: StringQuotes, prefix: StringPrefix) -> Cow<str> {
     // The normalized string if `input` is not yet normalized.
     // `output` must remain empty if `input` is already normalized.
     let mut output = String::new();
@@ -774,7 +781,22 @@ fn normalize_string(input: &str, quotes: StringQuotes, is_raw: bool) -> Cow<str>
 
     let mut chars = input.char_indices();
 
+    let is_raw = prefix.is_raw_string();
+    let is_fstring = prefix.is_fstring();
+    let mut in_formatted_value = false;
+
     while let Some((index, c)) = chars.next() {
+        if is_fstring && matches!(c, '{' | '}') {
+            if let Some(next) = input.as_bytes().get(index + 1).copied().map(char::from) {
+                if next == c {
+                    // Skip over the second character of the double braces
+                    chars.next();
+                } else {
+                    in_formatted_value = c == '{';
+                }
+            }
+            continue;
+        }
         if c == '\r' {
             output.push_str(&input[last_index..index]);
 
@@ -792,7 +814,7 @@ fn normalize_string(input: &str, quotes: StringQuotes, is_raw: bool) -> Cow<str>
             if c == '\\' {
                 if let Some(next) = input.as_bytes().get(index + 1).copied().map(char::from) {
                     #[allow(clippy::if_same_then_else)]
-                    if next == opposite_quote {
+                    if next == opposite_quote && !in_formatted_value {
                         // Remove the escape by ending before the backslash and starting again with the quote
                         chars.next();
                         output.push_str(&input[last_index..index]);
@@ -805,7 +827,7 @@ fn normalize_string(input: &str, quotes: StringQuotes, is_raw: bool) -> Cow<str>
                         chars.next();
                     }
                 }
-            } else if c == preferred_quote {
+            } else if c == preferred_quote && !in_formatted_value {
                 // Escape the quote
                 output.push_str(&input[last_index..index]);
                 output.push('\\');

scripts/formatter_ecosystem_checks.sh

@@ -64,7 +64,7 @@ git -C "$dir/cpython" checkout 1a1bfc28912a39b500c578e9f10a8a222638d411
 
 time cargo run --bin ruff_dev -- format-dev --stability-check \
   --error-file "$target/progress_projects_errors.txt" --log-file "$target/progress_projects_log.txt" --stats-file "$target/progress_projects_stats.txt" \
-  --files-with-errors 16 --multi-project "$dir" || (
+  --files-with-errors 15 --multi-project "$dir" || (
   echo "Ecosystem check failed"
   cat "$target/progress_projects_log.txt"
   exit 1