refactor(formatter_core): remove JS-only method (#28099)

Just inlined in `oxc_formatter`.

crates/oxc_formatter/src/utils/assignment_like.rs

@@ -200,7 +200,7 @@ impl<'a, 'b> AssignmentLike<'a, 'b> {
                 // Handle computed properties
                 if property.computed {
                     write!(f, ["[", property.key(), "]"]);
-                    f.source_text().span_width(property.key.span()) + 2 < text_width_for_break
+                    f.source_text().text_for(&property.key).width() + 2 < text_width_for_break
                 } else if property.shorthand {
                     let PropertyKey::StaticIdentifier(ident) = &property.key else {
                         unreachable!("Expected static identifier for shorthand property");
@@ -230,7 +230,7 @@ impl<'a, 'b> AssignmentLike<'a, 'b> {
                 // Handle computed properties
                 if property.computed {
                     write!(f, ["[", property.key(), "]"]);
-                    f.source_text().span_width(property.key.span()) + 2 < text_width_for_break
+                    f.source_text().text_for(&property.key).width() + 2 < text_width_for_break
                 } else {
                     let width = write_member_name(&property.key(), f);
 
@@ -243,7 +243,7 @@ impl<'a, 'b> AssignmentLike<'a, 'b> {
 
                 if property.computed {
                     write!(f, ["[", property.name(), "]"]);
-                    f.source_text().span_width(property.name.span()) + 2 < text_width_for_break
+                    f.source_text().text_for(&property.name).width() + 2 < text_width_for_break
                 } else {
                     let width = write_member_name(&property.name(), f);
 

crates/oxc_formatter/src/utils/object.rs

@@ -1,5 +1,6 @@
+use unicode_width::UnicodeWidthStr;
+
 use oxc_ast::ast::*;
-use oxc_span::GetSpan;
 use oxc_syntax::identifier::is_identifier_name_patched;
 
 use crate::{
@@ -87,7 +88,7 @@ pub fn write_member_name<'a>(
     } else {
         write!(f, key);
 
-        f.source_text().span_width(key.span())
+        f.source_text().text_for(key).width()
     }
 }
 

crates/oxc_formatter_core/src/source/text.rs

@@ -1,8 +1,6 @@
 use std::ops::Deref;
 
-use unicode_width::UnicodeWidthStr;
-
-use oxc_span::{GetSpan, Span};
+use oxc_span::GetSpan;
 
 /// Source text wrapper providing mechanical byte/offset access for the formatter.
 ///
@@ -110,10 +108,4 @@ impl<'a> SourceText<'a> {
     pub fn text_for<T: GetSpan>(&self, obj: &T) -> &'a str {
         obj.span().source_text(self.text)
     }
-
-    // Utility methods
-    /// Get the display width of span, the same measure as a printed string's width (wide characters count as 2)
-    pub fn span_width(&self, span: Span) -> usize {
-        self.text_for(&span).width()
-    }
 }