Merge 7aa59ea into 55e85ad

boa-dev · Feb 7, 2022 · 7f2bf40 · 7f2bf40
2 parents 55e85ad + 7aa59ea
commit 7f2bf40
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Showing 3 changed files with 16 additions and 6 deletions.
diff --git a/boa/src/syntax/parser/cursor/buffered_lexer/mod.rs b/boa/src/syntax/parser/cursor/buffered_lexer/mod.rs
@@ -17,12 +17,12 @@ const MAX_PEEK_SKIP: usize = 3;
 /// The fixed size of the buffer used for storing values that are peeked ahead.
 ///
 /// The size is calculated for a worst case scenario, where we want to peek `MAX_PEEK_SKIP` tokens
-/// skipping line terminators:
+/// skipping line terminators, and the stream ends just after:
 /// ```text
-/// [\n, B, \n, C, \n, D, \n, E, \n, F]
-///   0  0   1  1   2  2   3  3   4  4
+/// [\n, B, \n, C, \n, D, \n, E, \n, F, None]
+///   0  0   1  1   2  2   3  3   4  4  5
 /// ```
-const PEEK_BUF_SIZE: usize = (MAX_PEEK_SKIP + 1) * 2;
+const PEEK_BUF_SIZE: usize = (MAX_PEEK_SKIP + 1) * 2 + 1;
 
 #[derive(Debug)]
 pub(super) struct BufferedLexer<R> {
@@ -49,6 +49,7 @@ where
                 None::<Token>,
                 None::<Token>,
                 None::<Token>,
+                None::<Token>,
             ],
             read_index: 0,
             write_index: 0,

diff --git a/boa/src/syntax/parser/cursor/buffered_lexer/tests.rs b/boa/src/syntax/parser/cursor/buffered_lexer/tests.rs
@@ -278,3 +278,11 @@ fn skip_peeked_terminators() {
     // End of stream
     assert!(cur.peek(2, true, &mut interner).unwrap().is_none());
 }
+
+#[test]
+fn issue_1768() {
+    let mut cur = BufferedLexer::from(&b"\n(\nx\n)\n"[..]);
+    let mut interner = Interner::default();
+
+    assert!(cur.peek(3, true, &mut interner).unwrap().is_none());
+}
diff --git a/boa/src/syntax/parser/expression/assignment/mod.rs b/boa/src/syntax/parser/expression/assignment/mod.rs
@@ -153,8 +153,9 @@ where
                                         .map(Node::ArrowFunctionDecl);
                                     }
                                     TokenKind::Punctuator(Punctuator::CloseParen) => {
-                                        // Need to check if the token after the close paren is an arrow, if so then this is an ArrowFunction
-                                        // otherwise it is an expression of the form (b).
+                                        // Need to check if the token after the close paren is an
+                                        // arrow, if so then this is an ArrowFunction otherwise it
+                                        // is an expression of the form (b).
                                         if let Some(t) = cursor.peek(3, interner)? {
                                             if t.kind() == &TokenKind::Punctuator(Punctuator::Arrow)
                                             {