perf(formatter): optimize formatting literal string (#15380)

Author: Dunqing

crates/oxc_formatter/src/formatter/builders.rs

@@ -1,4 +1,4 @@
-use std::{backtrace, borrow::Cow, cell::Cell, num::NonZeroU8};
+use std::{backtrace, cell::Cell, num::NonZeroU8};
 
 use Tag::{
     EndAlign, EndConditionalContent, EndDedent, EndEntry, EndFill, EndGroup, EndIndent,
@@ -302,6 +302,23 @@ pub fn text(text: &str) -> Text<'_> {
     Text { text, width: None }
 }
 
+/// Creates a text from a dynamic string and a known width, for example,
+/// identifiers or numbers that do not contain line breaks.
+pub fn text_with_width(text: &str, width: TextWidth) -> Text<'_> {
+    if width.is_multiline() {
+        debug_assert!(
+            text.as_bytes().iter().any(|&b| matches!(b, b'\n' | b'\t')),
+            "Text with a known multiline width must contain at least one whitespace character. Found invalid content: '{text}'"
+        );
+    } else {
+        debug_assert!(
+            !text.as_bytes().iter().any(|&b| matches!(b, b'\n' | b'\t')),
+            "Text with a known width must not contain whitespace characters when the width is single line. Found invalid content: '{text}'"
+        );
+    }
+    Text { text, width: Some(width) }
+}
+
 #[derive(Eq, PartialEq)]
 pub struct Text<'a> {
     text: &'a str,
@@ -325,49 +342,6 @@ impl std::fmt::Debug for Text<'_> {
     }
 }
 
-/// String that is the same as in the input source text if `text` is [`Cow::Borrowed`] or
-/// some replaced content if `text` is [`Cow::Owned`].
-pub fn syntax_token_cow_slice(text: Cow<'_, str>, span: Span) -> SyntaxTokenCowSlice<'_> {
-    debug_assert_no_newlines(&text);
-    SyntaxTokenCowSlice { text, span }
-}
-
-pub struct SyntaxTokenCowSlice<'a> {
-    text: Cow<'a, str>,
-    span: Span,
-}
-
-impl<'a> Format<'a> for SyntaxTokenCowSlice<'a> {
-    fn fmt(&self, f: &mut Formatter<'_, 'a>) -> FormatResult<()> {
-        match &self.text {
-            Cow::Borrowed(content) => {
-                // let range = TextRange::at(self.start, text.text_len());
-                // debug_assert_eq!(
-                // *text,
-                // &self.token.token()[range - self.token.text_range().start()],
-                // "The borrowed string doesn't match the specified token substring. Does the borrowed string belong to this token and range?"
-                // );
-
-                // let relative_range = range - self.token.text_range().start();
-                // let slice = self.token.token_text().slice(relative_range);
-
-                text(f.source_text().text_for(&self.span)).fmt(f)
-            }
-            Cow::Owned(text) => f.write_element(FormatElement::Text {
-                // TODO: Should use arena String to replace Cow::Owned.
-                text: f.context().allocator().alloc_str(text),
-                width: TextWidth::from_text(text, f.options().indent_width),
-            }),
-        }
-    }
-}
-
-impl std::fmt::Debug for SyntaxTokenCowSlice<'_> {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        std::write!(f, "SyntaxTokenCowSlice({})", self.text)
-    }
-}
-
 #[track_caller]
 fn debug_assert_no_newlines(text: &str) {
     debug_assert!(

crates/oxc_formatter/src/formatter/format_element/mod.rs

@@ -420,6 +420,11 @@ impl TextWidth {
         Self::Width(Width::new(width))
     }
 
+    pub fn from_len(len: usize) -> TextWidth {
+        #[expect(clippy::cast_possible_truncation)]
+        TextWidth::Width(Width::new(len as u32))
+    }
+
     pub const fn width(self) -> Option<Width> {
         match self {
             TextWidth::Width(width) => Some(width),

crates/oxc_formatter/src/formatter/token/number.rs

@@ -40,7 +40,9 @@ pub struct CleanedNumberLiteralText<'a> {
 
 impl<'a> Format<'a> for CleanedNumberLiteralText<'a> {
     fn fmt(&self, f: &mut Formatter<'_, 'a>) -> FormatResult<()> {
-        syntax_token_cow_slice(format_trimmed_number(self.text, self.options), self.span).fmt(f)
+        let text = format_trimmed_number(self.text, self.options);
+        let width = TextWidth::from_len(text.len());
+        text_with_width(f.context().allocator().alloc_str(&text), width).fmt(f)
     }
 }
 

crates/oxc_formatter/src/utils/assignment_like.rs

@@ -27,7 +27,7 @@ use crate::{
     },
 };
 
-use super::string_utils::{FormatLiteralStringToken, StringLiteralParentKind};
+use super::string::{FormatLiteralStringToken, StringLiteralParentKind};
 
 #[derive(Clone, Copy)]
 pub enum AssignmentLike<'a, 'b> {

crates/oxc_formatter/src/utils/mod.rs

@@ -8,7 +8,7 @@ pub mod jsx;
 pub mod member_chain;
 pub mod object;
 pub mod statement_body;
-pub mod string_utils;
+pub mod string;
 pub mod suppressed;
 pub mod typecast;
 pub mod typescript;

crates/oxc_formatter/src/utils/object.rs

@@ -6,7 +6,7 @@ use crate::{
     Buffer, Format, FormatResult,
     ast_nodes::{AstNode, AstNodes},
     formatter::Formatter,
-    utils::string_utils::{FormatLiteralStringToken, StringLiteralParentKind},
+    utils::string::{FormatLiteralStringToken, StringLiteralParentKind},
     write,
 };