feat: tag parser (#1745)

plugin/gomark/parser/tag.go

+package parser
+
+import "github.com/usememos/memos/plugin/gomark/parser/tokenizer"
+
+type TagParser struct {
+	ContentTokens []*tokenizer.Token
+}
+
+func NewTagParser() *TagParser {
+	return &TagParser{}
+}
+
+func (*TagParser) Match(tokens []*tokenizer.Token) *TagParser {
+	if len(tokens) < 2 {
+		return nil
+	}
+	if tokens[0].Type != tokenizer.Hash {
+		return nil
+	}
+	contentTokens := []*tokenizer.Token{}
+	for _, token := range tokens[1:] {
+		if token.Type == tokenizer.Newline || token.Type == tokenizer.Space || token.Type == tokenizer.Hash {
+			break
+		}
+		contentTokens = append(contentTokens, token)
+	}
+	if len(contentTokens) == 0 {
+		return nil
+	}
+
+	return &TagParser{
+		ContentTokens: contentTokens,
+	}
+}

plugin/gomark/parser/tag_test.go

+package parser
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"github.com/usememos/memos/plugin/gomark/parser/tokenizer"
+)
+
+func TestTagParser(t *testing.T) {
+	tests := []struct {
+		text string
+		tag  *TagParser
+	}{
+		{
+			text: "*Hello world",
+			tag:  nil,
+		},
+		{
+			text: "# Hello World",
+			tag:  nil,
+		},
+		{
+			text: "#tag",
+			tag: &TagParser{
+				ContentTokens: []*tokenizer.Token{
+					{
+						Type:  tokenizer.Text,
+						Value: "tag",
+					},
+				},
+			},
+		},
+		{
+			text: "#tag/subtag",
+			tag: &TagParser{
+				ContentTokens: []*tokenizer.Token{
+					{
+						Type:  tokenizer.Text,
+						Value: "tag/subtag",
+					},
+				},
+			},
+		},
+	}
+
+	for _, test := range tests {
+		tokens := tokenizer.Tokenize(test.text)
+		require.Equal(t, test.tag, NewTagParser().Match(tokens))
+	}
+}