markdown: allow any character to be used as heading IDs (#84)

internal/store/markdown.go

@@ -6,6 +6,7 @@ package store
 
 import (
 	"bytes"
+	"fmt"
 	"net/url"
 	"os"
 	"path"
@@ -21,6 +22,7 @@ import (
 	"github.com/yuin/goldmark/parser"
 	goldmarkhtml "github.com/yuin/goldmark/renderer/html"
 	"github.com/yuin/goldmark/text"
+	"github.com/yuin/goldmark/util"
 )
 
 func convertFile(pathPrefix, file string) (content []byte, meta map[string]any, headings goldmarktoc.Items, err error) {
@@ -50,7 +52,11 @@ func convertFile(pathPrefix, file string) (content []byte, meta map[string]any,
 		),
 	)
 
-	ctx := parser.NewContext()
+	ctx := parser.NewContext(
+		func(cfg *parser.ContextConfig) {
+			cfg.IDs = newIDs()
+		},
+	)
 	doc := md.Parser().Parse(text.NewReader(body), parser.WithContext(ctx))
 
 	// Headings
@@ -135,3 +141,43 @@ func inspectLinks(pathPrefix string, doc ast.Node) error {
 		return ast.WalkSkipChildren, nil
 	})
 }
+
+// ids is a modified version to allow any non-whitespace characters instead of
+// just alphabets or numerics from
+// https://github.com/yuin/goldmark/blob/113ae87dd9e662b54012a596671cb38f311a8e9c/parser/parser.go#L65.
+type ids struct {
+	values map[string]bool
+}
+
+func newIDs() parser.IDs {
+	return &ids{
+		values: map[string]bool{},
+	}
+}
+
+func (s *ids) Generate(value []byte, kind ast.NodeKind) []byte {
+	value = util.TrimLeftSpace(value)
+	value = util.TrimRightSpace(value)
+	if len(value) == 0 {
+		if kind == ast.KindHeading {
+			value = []byte("heading")
+		} else {
+			value = []byte("id")
+		}
+	}
+	if _, ok := s.values[util.BytesToReadOnlyString(value)]; !ok {
+		s.values[util.BytesToReadOnlyString(value)] = true
+		return value
+	}
+	for i := 1; ; i++ {
+		newResult := fmt.Sprintf("%s-%d", value, i)
+		if _, ok := s.values[newResult]; !ok {
+			s.values[newResult] = true
+			return []byte(newResult)
+		}
+	}
+}
+
+func (s *ids) Put(value []byte) {
+	s.values[util.BytesToReadOnlyString(value)] = true
+}

internal/store/markdown_test.go

@@ -0,0 +1,55 @@
+// Copyright 2022 ASoulDocs. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package store
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/yuin/goldmark/ast"
+)
+
+func TestIDs_Generate(t *testing.T) {
+	ids := newIDs()
+
+	tests := []struct {
+		name  string
+		value string
+		kind  ast.NodeKind
+		want  string
+	}{
+		{
+			name:  "normal",
+			value: "Hello, 世界",
+			kind:  ast.KindHeading,
+			want:  "Hello, 世界",
+		},
+		{
+			name:  "empty heading",
+			value: "",
+			kind:  ast.KindHeading,
+			want:  "heading",
+		},
+		{
+			name:  "empty id",
+			value: "",
+			kind:  ast.KindImage,
+			want:  "id",
+		},
+
+		{
+			name:  "duplicated heading",
+			value: "",
+			kind:  ast.KindHeading,
+			want:  "heading-1",
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			got := ids.Generate([]byte(test.value), test.kind)
+			assert.Equal(t, test.want, string(got))
+		})
+	}
+}