fix: support comments at end of raw go expressions (#871)

Co-authored-by: Adrian Hesketh <adrianhesketh@hushmail.com>

Author: knudtty

.version

@@ -1 +1 @@
-0.2.759
+0.2.763

parser/v2/gocodeparser_test.go

@@ -91,6 +91,32 @@ func TestGoCodeParser(t *testing.T) {
 				Multiline: true,
 			},
 		},
+		{
+			name: "comments in expression",
+			input: `{{
+	one := "one"
+	two := "two"
+	// Comment in middle of expression.
+	four := "four"
+	// Comment at end of expression.
+}}`,
+			expected: GoCode{
+				Expression: Expression{
+					Value: `
+	one := "one"
+	two := "two"
+	// Comment in middle of expression.
+	four := "four"
+	// Comment at end of expression.`,
+					Range: Range{
+						From: Position{Index: 2, Line: 0, Col: 2},
+						To:   Position{Index: 117, Line: 5, Col: 33},
+					},
+				},
+				TrailingSpace: SpaceNone,
+				Multiline:     true,
+			},
+		},
 	}
 	for _, tt := range tests {
 		tt := tt

parser/v2/goexpression/parse.go

@@ -112,7 +112,7 @@ func TemplExpression(src string) (start, end int, err error) {
 	errorHandler := func(pos token.Position, msg string) {
 		err = fmt.Errorf("error parsing expression: %v", msg)
 	}
-	s.Init(file, []byte(src), errorHandler, 0)
+	s.Init(file, []byte(src), errorHandler, scanner.ScanComments)
 
 	// Read chains of identifiers, e.g.:
 	// components.Variable
@@ -140,7 +140,7 @@ func Expression(src string) (start, end int, err error) {
 	errorHandler := func(pos token.Position, msg string) {
 		err = fmt.Errorf("error parsing expression: %v", msg)
 	}
-	s.Init(file, []byte(src), errorHandler, 0)
+	s.Init(file, []byte(src), errorHandler, scanner.ScanComments)
 
 	// Read chains of identifiers and constants up until RBRACE, e.g.:
 	// true
@@ -183,6 +183,8 @@ loop:
 			end = int(pos) + len(lit) - 1
 		case token.SEMICOLON:
 			continue
+		case token.COMMENT:
+			end = int(pos) + len(lit) - 1
 		case token.ILLEGAL:
 			return 0, 0, fmt.Errorf("illegal token: %v", lit)
 		default: