fix(es/parser): Improve error message for template literals (#10690)

Author: bvanjoi

crates/swc_ecma_lexer/src/common/parser/mod.rs

@@ -513,6 +513,8 @@ pub fn parse_shebang<'a>(p: &mut impl Parser<'a>) -> PResult<Option<Atom>> {
  })
 }
 
+#[cold]
+#[inline(never)]
 pub fn eof_error<'a, P: Parser<'a>>(p: &mut P) -> crate::error::Error {
  debug_assert!(
  p.input_mut().cur().is_none(),

crates/swc_ecma_parser/src/parser/macros.rs

@@ -1,25 +1,3 @@
-macro_rules! cur {
- ($p:expr, true) => {{
- match $p.input_mut().cur() {
- Some(c) => {
- if *c == Token::Error {
- let c = $p.input_mut().bump();
- let err = c.take_error($p.input_mut());
- return Err(err);
- } else {
- c
- }
- }
- None => {
- let pos = $p.input().end_pos();
- let span = Span::new(pos, pos);
- let err = crate::error::Error::new(span, crate::error::SyntaxError::Eof);
- return Err(err);
- }
- }
- }};
-}
-
 macro_rules! trace_cur {
  ($p:expr, $name:ident) => {{
  if cfg!(feature = "debug") {

crates/swc_ecma_parser/src/parser/tpl.rs

@@ -3,7 +3,9 @@ use swc_ecma_ast::*;
 use swc_ecma_lexer::{
  common::{
  lexer::token::TokenFactory,
- parser::{buffer::Buffer, typescript::parse_ts_type, PResult, Parser as ParserTrait},
+ parser::{
+ buffer::Buffer, eof_error, typescript::parse_ts_type, PResult, Parser as ParserTrait,
+ },
  },
  error::SyntaxError,
 };
@@ -132,50 +134,56 @@ impl<I: Tokens> Parser<I> {
  self.input_mut().rescan_template_token(false);
  }
  let start = self.cur_pos();
- let (raw, cooked, tail, span) = match *cur!(self, true) {
- Token::TemplateMiddle => match self.bump() {
- t @ Token::TemplateMiddle => {
- let (cooked, raw) = t.take_template(self.input_mut());
- let pos = self.input.prev_span().hi;
- debug_assert!(start.0 <= pos.0 - 2);
- // case: ___${
- // `pos.0 - 2` means skip '${'
- let span = Span::new(start, BytePos::from_u32(pos.0 - 2));
- match cooked {
- Ok(cooked) => (raw, Some(cooked), false, span),
- Err(err) => {
- if is_tagged_tpl {
- (raw, None, false, span)
- } else {
- return Err(err);
- }
+ let Some(cur) = self.input_mut().cur() else {
+ return Err(eof_error(self));
+ };
+ let (raw, cooked, tail, span) = match *cur {
+ Token::TemplateMiddle => {
+ let t = self.bump();
+ let (cooked, raw) = t.take_template(self.input_mut());
+ let pos = self.input.prev_span().hi;
+ debug_assert!(start.0 <= pos.0 - 2);
+ // case: ___${
+ // `pos.0 - 2` means skip '${'
+ let span = Span::new(start, BytePos::from_u32(pos.0 - 2));
+ match cooked {
+ Ok(cooked) => (raw, Some(cooked), false, span),
+ Err(err) => {
+ if is_tagged_tpl {
+ (raw, None, false, span)
+ } else {
+ return Err(err);
  }
  }
  }
- _ => unreachable!(),
- },
- Token::TemplateTail => match self.bump() {
- t @ Token::TemplateTail => {
- let (cooked, raw) = t.take_template(self.input_mut());
- let pos = self.input.prev_span().hi;
- debug_assert!(start.0 < pos.0);
- // case: ____`
- // `pos.0 - 1` means skip '`'
- let span = Span::new(start, BytePos::from_u32(pos.0 - 1));
- match cooked {
- Ok(cooked) => (raw, Some(cooked), true, span),
- Err(err) => {
- if is_tagged_tpl {
- (raw, None, true, span)
- } else {
- return Err(err);
- }
+ }
+ Token::TemplateTail => {
+ let t = self.bump();
+ let (cooked, raw) = t.take_template(self.input_mut());
+ let pos = self.input.prev_span().hi;
+ debug_assert!(start.0 < pos.0);
+ // case: ____`
+ // `pos.0 - 1` means skip '`'
+ let span = Span::new(start, BytePos::from_u32(pos.0 - 1));
+ match cooked {
+ Ok(cooked) => (raw, Some(cooked), true, span),
+ Err(err) => {
+ if is_tagged_tpl {
+ (raw, None, true, span)
+ } else {
+ return Err(err);
  }
  }
  }
- _ => unreachable!(),
- },
- _ => unexpected!(self, "TemplateMiddle or TemplateTail"),
+ }
+ Token::Error => {
+ let t = self.input_mut().bump();
+ let err = t.take_error(self.input_mut());
+ return Err(err);
+ }
+ _ => {
+ unexpected!(self, "`}`")
+ }
  };
 
  Ok(TplElement {

crates/swc_ecma_parser/tests/test262-error-references/fail/1acada3c651821cf.js.swc-stderr

@@ -1,4 +1,4 @@
- x Unexpected token `;`. Expected TemplateMiddle or TemplateTail
+ x Unexpected token `;`. Expected `}`
  ,-[$DIR/tests/test262-parser/fail/1acada3c651821cf.js:1:1]
  1 | `hello ${10;test`
  : ^