From ac022ce0ab9a7004c1a2df25acbac0729dd01aa9 Mon Sep 17 00:00:00 2001
From: Ben Johnson <benbjohnson@yahoo.com>
Date: Tue, 21 Sep 2021 08:29:30 -0600
Subject: [PATCH] CORE-860: Handle SQL comments during scan

---
 sql2/scanner.go      | 12 ++++++++++++
 sql2/scanner_test.go |  3 +++
 2 files changed, 15 insertions(+)

diff --git a/sql2/scanner.go b/sql2/scanner.go
index 552034a83..105f321b1 100644
--- a/sql2/scanner.go
+++ b/sql2/scanner.go
@@ -104,6 +104,11 @@ func (s *Scanner) Scan() (pos Pos, token Token, lit string) {
 		case '+':
 			return pos, PLUS, "+"
 		case '-':
+			if s.peek() == '-' {
+				s.read()
+				s.skipComment()
+				continue
+			}
 			return pos, MINUS, "-"
 		case '*':
 			return pos, STAR, "*"
@@ -117,6 +122,13 @@ func (s *Scanner) Scan() (pos Pos, token Token, lit string) {
 	}
 }
 
+// skipComment reads all characters until the end of the line or EOF.
+func (s *Scanner) skipComment() {
+	for ch := s.peek(); ch != '\n' && ch != -1; ch = s.peek() {
+		s.read()
+	}
+}
+
 func (s *Scanner) scanUnquotedIdent(pos Pos, prefix string) (Pos, Token, string) {
 	assert(isUnquotedIdent(s.peek()))
 
diff --git a/sql2/scanner_test.go b/sql2/scanner_test.go
index 27e33222d..f4a25a0aa 100644
--- a/sql2/scanner_test.go
+++ b/sql2/scanner_test.go
@@ -38,6 +38,9 @@ func TestScanner_Scan(t *testing.T) {
 		t.Run("StartingX", func(t *testing.T) {
 			AssertScan(t, `xyz`, sql.IDENT, `xyz`)
 		})
+		t.Run("WithComment", func(t *testing.T) {
+			AssertScan(t, "-- this is a comment\n\n-- more comments\nfoo", sql.IDENT, `foo`)
+		})
 	})
 
 	t.Run("KEYWORD", func(t *testing.T) {