chore: handle newline in block parsers

plugin/gomark/parser/heading.go

@@ -36,11 +36,11 @@ func (*HeadingParser) Match(tokens []*tokenizer.Token) (int, bool) {
 	cursor++
 	contentTokens := []*tokenizer.Token{}
 	for _, token := range tokens[cursor:] {
+		contentTokens = append(contentTokens, token)
+		cursor++
 		if token.Type == tokenizer.Newline {
 			break
 		}
-		contentTokens = append(contentTokens, token)
-		cursor++
 	}
 	if len(contentTokens) == 0 {
 		return 0, false

plugin/gomark/parser/heading_test.go

@@ -53,6 +53,7 @@ Hello World`,
 					&ast.Text{
 						Content: "123 ",
 					},
+					&ast.LineBreak{},
 				},
 			},
 		},

plugin/gomark/parser/horizontal_rule.go

@@ -26,8 +26,11 @@ func (*HorizontalRuleParser) Match(tokens []*tokenizer.Token) (int, bool) {
 	if len(tokens) > 3 && tokens[3].Type != tokenizer.Newline {
 		return 0, false
 	}
+	if len(tokens) == 3 {
 		return 3, true
 	}
+	return 4, true
+}
 
 func (p *HorizontalRuleParser) Parse(tokens []*tokenizer.Token) (ast.Node, error) {
 	size, ok := p.Match(tokens)

plugin/gomark/parser/horizontal_rule_test.go

@@ -20,6 +20,12 @@ func TestHorizontalRuleParser(t *testing.T) {
 				Symbol: "-",
 			},
 		},
+		{
+			text: "---\naaa",
+			horizontalRule: &ast.HorizontalRule{
+				Symbol: "-",
+			},
+		},
 		{
 			text:           "****",
 			horizontalRule: nil,