From 75871774295c8025ee598ecc7fa35490372fbfd2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Medeiros?= <andre@cronolink.com.br>
Date: Thu, 7 May 2026 13:15:12 -0300
Subject: [PATCH] Fix ASI not firing before <template> in class bodies

The upstream JS scanner suppresses automatic semicolon insertion before
`<` because in standard JS it could be a less-than operator. In GJS/GTS,
`<template>` is a valid class body member, which caused field definitions
without a trailing semicolon to not be recognised when followed by a
template tag.

Fix this in scanner.c by intercepting the AUTOMATIC_SEMICOLON case before
delegating to the JS scanner. We call scan_automatic_semicolon directly
(accessible from the included scanner.h), and when it refuses due to `<`,
we peek ahead for `template>` and emit the semicolon ourselves.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 src/scanner.c           | 28 ++++++++++++++++++++++++++++
 test/corpus/glimmer.txt | 25 +++++++++++++++++++++++++
 2 files changed, 53 insertions(+)

diff --git a/src/scanner.c b/src/scanner.c
index feb104e..b40a7a9 100644
--- a/src/scanner.c
+++ b/src/scanner.c
@@ -63,5 +63,33 @@ bool tree_sitter_glimmer_javascript_external_scanner_scan(void *payload, TSLexer
     if (valid_symbols[RAW_TEXT]) {
         return scan_raw_text(payload, lexer);
     }
+
+    // The upstream JS scanner refuses to insert an automatic semicolon before `<`
+    // because in standard JS it could be a less-than operator. In GJS/GTS, `<template>`
+    // is a valid class body member, so we handle the AUTOMATIC_SEMICOLON case ourselves:
+    // we call scan_automatic_semicolon directly (accessible from the included scanner.h),
+    // and when it refuses due to `<`, we check whether `<template>` follows and insert
+    // the semicolon if so.
+    if (valid_symbols[AUTOMATIC_SEMICOLON]) {
+        bool scanned_comment = false;
+        bool result = scan_automatic_semicolon(lexer, !valid_symbols[LOGICAL_OR], &scanned_comment);
+        if (!result && !scanned_comment) {
+            if (lexer->lookahead == '<') {
+                skip(lexer);
+                const char *tag = "template>";
+                for (unsigned i = 0; tag[i] != '\0'; i++) {
+                    if ((char)lexer->lookahead != tag[i]) return false;
+                    skip(lexer);
+                }
+                lexer->result_symbol = AUTOMATIC_SEMICOLON;
+                return true;
+            }
+            if (valid_symbols[TERNARY_QMARK] && lexer->lookahead == '?') {
+                return scan_ternary_qmark(lexer);
+            }
+        }
+        return result;
+    }
+
     return tree_sitter_javascript_external_scanner_scan(payload, lexer, valid_symbols);
 }
diff --git a/test/corpus/glimmer.txt b/test/corpus/glimmer.txt
index 28f2ec3..3895229 100644
--- a/test/corpus/glimmer.txt
+++ b/test/corpus/glimmer.txt
@@ -155,6 +155,31 @@ class InClass {
         (glimmer_closing_tag
           (glimmer_template_tag_name))))))
 
+============================================
+Class Component with Field Without Semicolon
+============================================
+
+class Foo {
+  foo = bar
+  <template>{{this.foo}}</template>
+}
+
+----
+
+(program
+  (class_declaration
+    (identifier)
+    (class_body
+      (field_definition
+        (property_identifier)
+        (identifier))
+      (glimmer_template
+        (glimmer_opening_tag
+          (glimmer_template_tag_name))
+        (raw_text)
+        (glimmer_closing_tag
+          (glimmer_template_tag_name))))))
+
 ============================================
 JS Regex Evasion
 ============================================