Refactor markdown attention render (#29984)

Follow #29833 and add tests

modules/markup/markdown/goldmark.go

@@ -27,7 +27,21 @@ import (
 )
 
 // ASTTransformer is a default transformer of the goldmark tree.
-type ASTTransformer struct{}
+type ASTTransformer struct {
+	AttentionTypes container.Set[string]
+}
+
+func NewASTTransformer() *ASTTransformer {
+	return &ASTTransformer{
+		AttentionTypes: container.SetOf("note", "tip", "important", "warning", "caution"),
+	}
+}
+
+func (g *ASTTransformer) applyElementDir(n ast.Node) {
+	if markup.DefaultProcessorHelper.ElementDir != "" {
+		n.SetAttributeString("dir", []byte(markup.DefaultProcessorHelper.ElementDir))
+	}
+}
 
 // Transform transforms the given AST tree.
 func (g *ASTTransformer) Transform(node *ast.Document, reader text.Reader, pc parser.Context) {
@@ -45,12 +59,6 @@ func (g *ASTTransformer) Transform(node *ast.Document, reader text.Reader, pc pa
 		tocMode = rc.TOC
 	}
 
-	applyElementDir := func(n ast.Node) {
-		if markup.DefaultProcessorHelper.ElementDir != "" {
-			n.SetAttributeString("dir", []byte(markup.DefaultProcessorHelper.ElementDir))
-		}
-	}
-
 	_ = ast.Walk(node, func(n ast.Node, entering bool) (ast.WalkStatus, error) {
 		if !entering {
 			return ast.WalkContinue, nil
@@ -72,9 +80,9 @@ func (g *ASTTransformer) Transform(node *ast.Document, reader text.Reader, pc pa
 				header.ID = util.BytesToReadOnlyString(id.([]byte))
 			}
 			tocList = append(tocList, header)
-			applyElementDir(v)
+			g.applyElementDir(v)
 		case *ast.Paragraph:
-			applyElementDir(v)
+			g.applyElementDir(v)
 		case *ast.Image:
 			// Images need two things:
 			//
@@ -174,7 +182,7 @@ func (g *ASTTransformer) Transform(node *ast.Document, reader text.Reader, pc pa
 					v.AppendChild(v, newChild)
 				}
 			}
-			applyElementDir(v)
+			g.applyElementDir(v)
 		case *ast.Text:
 			if v.SoftLineBreak() && !v.HardLineBreak() {
 				if ctx.Metas["mode"] != "document" {
@@ -189,51 +197,7 @@ func (g *ASTTransformer) Transform(node *ast.Document, reader text.Reader, pc pa
 				v.AppendChild(v, NewColorPreview(colorContent))
 			}
 		case *ast.Blockquote:
-			// We only want attention blockquotes when the AST looks like:
-			// Text: "["
-			// Text: "!TYPE"
-			// Text(SoftLineBreak): "]"
-
-			// grab these nodes and make sure we adhere to the attention blockquote structure
-			firstParagraph := v.FirstChild()
-			if firstParagraph.ChildCount() < 3 {
-				return ast.WalkContinue, nil
-			}
-			firstTextNode, ok := firstParagraph.FirstChild().(*ast.Text)
-			if !ok || string(firstTextNode.Segment.Value(reader.Source())) != "[" {
-				return ast.WalkContinue, nil
-			}
-			secondTextNode, ok := firstTextNode.NextSibling().(*ast.Text)
-			if !ok || !attentionTypeRE.MatchString(string(secondTextNode.Segment.Value(reader.Source()))) {
-				return ast.WalkContinue, nil
-			}
-			thirdTextNode, ok := secondTextNode.NextSibling().(*ast.Text)
-			if !ok || string(thirdTextNode.Segment.Value(reader.Source())) != "]" {
-				return ast.WalkContinue, nil
-			}
-
-			// grab attention type from markdown source
-			attentionType := strings.ToLower(strings.TrimPrefix(string(secondTextNode.Segment.Value(reader.Source())), "!"))
-
-			// color the blockquote
-			v.SetAttributeString("class", []byte("attention-header attention-"+attentionType))
-
-			// create an emphasis to make it bold
-			attentionParagraph := ast.NewParagraph()
-			emphasis := ast.NewEmphasis(2)
-			emphasis.SetAttributeString("class", []byte("attention-"+attentionType))
-
-			// capitalize first letter
-			attentionText := ast.NewString([]byte(strings.ToUpper(string(attentionType[0])) + attentionType[1:]))
-
-			// replace the ![TYPE] with a dedicated paragraph of icon+Type
-			emphasis.AppendChild(emphasis, attentionText)
-			attentionParagraph.AppendChild(attentionParagraph, NewAttention(attentionType))
-			attentionParagraph.AppendChild(attentionParagraph, emphasis)
-			firstParagraph.Parent().InsertBefore(firstParagraph.Parent(), firstParagraph, attentionParagraph)
-			firstParagraph.RemoveChild(firstParagraph, firstTextNode)
-			firstParagraph.RemoveChild(firstParagraph, secondTextNode)
-			firstParagraph.RemoveChild(firstParagraph, thirdTextNode)
+			return g.transformBlockquote(v, reader)
 		}
 		return ast.WalkContinue, nil
 	})
@@ -268,7 +232,7 @@ func (p *prefixedIDs) Generate(value []byte, kind ast.NodeKind) []byte {
 	return p.GenerateWithDefault(value, dft)
 }
 
-// Generate generates a new element id.
+// GenerateWithDefault generates a new element id.
 func (p *prefixedIDs) GenerateWithDefault(value, dft []byte) []byte {
 	result := common.CleanValue(value)
 	if len(result) == 0 {
@@ -303,7 +267,8 @@ func newPrefixedIDs() *prefixedIDs {
 // in the gitea form.
 func NewHTMLRenderer(opts ...html.Option) renderer.NodeRenderer {
 	r := &HTMLRenderer{
-		Config: html.NewConfig(),
+		Config:      html.NewConfig(),
+		reValidName: regexp.MustCompile("^[a-z ]+$"),
 	}
 	for _, opt := range opts {
 		opt.SetHTMLOption(&r.Config)
@@ -315,6 +280,7 @@ func NewHTMLRenderer(opts ...html.Option) renderer.NodeRenderer {
 // renders gitea specific features.
 type HTMLRenderer struct {
 	html.Config
+	reValidName *regexp.Regexp
 }
 
 // RegisterFuncs implements renderer.NodeRenderer.RegisterFuncs.
@@ -442,11 +408,6 @@ func (r *HTMLRenderer) renderSummary(w util.BufWriter, source []byte, node ast.N
 	return ast.WalkContinue, nil
 }
 
-var (
-	validNameRE     = regexp.MustCompile("^[a-z ]+$")
-	attentionTypeRE = regexp.MustCompile("^!(NOTE|TIP|IMPORTANT|WARNING|CAUTION)$")
-)
-
 func (r *HTMLRenderer) renderIcon(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
 	if !entering {
 		return ast.WalkContinue, nil
@@ -461,7 +422,7 @@ func (r *HTMLRenderer) renderIcon(w util.BufWriter, source []byte, node ast.Node
 		return ast.WalkContinue, nil
 	}
 
-	if !validNameRE.MatchString(name) {
+	if !r.reValidName.MatchString(name) {
 		// skip this
 		return ast.WalkContinue, nil
 	}

modules/markup/markdown/markdown.go

@@ -126,7 +126,7 @@ func SpecializedMarkdown() goldmark.Markdown {
 				parser.WithAttribute(),
 				parser.WithAutoHeadingID(),
 				parser.WithASTTransformers(
-					util.Prioritized(&ASTTransformer{}, 10000),
+					util.Prioritized(NewASTTransformer(), 10000),
 				),
 			),
 			goldmark.WithRendererOptions(

modules/markup/markdown/markdown_test.go

@@ -16,9 +16,12 @@ import (
 	"code.gitea.io/gitea/modules/markup"
 	"code.gitea.io/gitea/modules/markup/markdown"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/svg"
 	"code.gitea.io/gitea/modules/util"
 
 	"github.com/stretchr/testify/assert"
+	"golang.org/x/text/cases"
+	"golang.org/x/text/language"
 )
 
 const (
@@ -957,3 +960,36 @@ space</p>
 		assert.Equal(t, template.HTML(c.Expected), result, "Unexpected result in testcase %v", i)
 	}
 }
+
+func TestAttention(t *testing.T) {
+	defer svg.MockIcon("octicon-info")()
+	defer svg.MockIcon("octicon-light-bulb")()
+	defer svg.MockIcon("octicon-report")()
+	defer svg.MockIcon("octicon-alert")()
+	defer svg.MockIcon("octicon-stop")()
+
+	renderAttention := func(attention, icon string) string {
+		tmpl := `<blockquote class="attention-header attention-{attention}"><p><svg class="attention-icon attention-{attention} svg {icon}" width="16" height="16"></svg><strong class="attention-{attention}">{Attention}</strong></p>`
+		tmpl = strings.ReplaceAll(tmpl, "{attention}", attention)
+		tmpl = strings.ReplaceAll(tmpl, "{icon}", icon)
+		tmpl = strings.ReplaceAll(tmpl, "{Attention}", cases.Title(language.English).String(attention))
+		return tmpl
+	}
+
+	test := func(input, expected string) {
+		result, err := markdown.RenderString(&markup.RenderContext{Ctx: context.Background()}, input)
+		assert.NoError(t, err)
+		assert.Equal(t, strings.TrimSpace(expected), strings.TrimSpace(string(result)))
+	}
+
+	test(`
+> [!NOTE]
+> text
+`, renderAttention("note", "octicon-info")+"\n<p>text</p>\n</blockquote>")
+
+	test(`> [!note]`, renderAttention("note", "octicon-info")+"\n</blockquote>")
+	test(`> [!tip]`, renderAttention("tip", "octicon-light-bulb")+"\n</blockquote>")
+	test(`> [!important]`, renderAttention("important", "octicon-report")+"\n</blockquote>")
+	test(`> [!warning]`, renderAttention("warning", "octicon-alert")+"\n</blockquote>")
+	test(`> [!caution]`, renderAttention("caution", "octicon-stop")+"\n</blockquote>")
+}

modules/markup/markdown/transform_blockquote.go

@@ -0,0 +1,67 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markdown
+
+import (
+	"strings"
+
+	"github.com/yuin/goldmark/ast"
+	"github.com/yuin/goldmark/text"
+	"golang.org/x/text/cases"
+	"golang.org/x/text/language"
+)
+
+func (g *ASTTransformer) transformBlockquote(v *ast.Blockquote, reader text.Reader) (ast.WalkStatus, error) {
+	// We only want attention blockquotes when the AST looks like:
+	// > Text("[") Text("!TYPE") Text("]")
+
+	// grab these nodes and make sure we adhere to the attention blockquote structure
+	firstParagraph := v.FirstChild()
+	g.applyElementDir(firstParagraph)
+	if firstParagraph.ChildCount() < 3 {
+		return ast.WalkContinue, nil
+	}
+	node1, ok1 := firstParagraph.FirstChild().(*ast.Text)
+	node2, ok2 := node1.NextSibling().(*ast.Text)
+	node3, ok3 := node2.NextSibling().(*ast.Text)
+	if !ok1 || !ok2 || !ok3 {
+		return ast.WalkContinue, nil
+	}
+	val1 := string(node1.Segment.Value(reader.Source()))
+	val2 := string(node2.Segment.Value(reader.Source()))
+	val3 := string(node3.Segment.Value(reader.Source()))
+	if val1 != "[" || val3 != "]" || !strings.HasPrefix(val2, "!") {
+		return ast.WalkContinue, nil
+	}
+
+	// grab attention type from markdown source
+	attentionType := strings.ToLower(val2[1:])
+	if !g.AttentionTypes.Contains(attentionType) {
+		return ast.WalkContinue, nil
+	}
+
+	// color the blockquote
+	v.SetAttributeString("class", []byte("attention-header attention-"+attentionType))
+
+	// create an emphasis to make it bold
+	attentionParagraph := ast.NewParagraph()
+	g.applyElementDir(attentionParagraph)
+	emphasis := ast.NewEmphasis(2)
+	emphasis.SetAttributeString("class", []byte("attention-"+attentionType))
+
+	attentionAstString := ast.NewString([]byte(cases.Title(language.English).String(attentionType)))
+
+	// replace the ![TYPE] with a dedicated paragraph of icon+Type
+	emphasis.AppendChild(emphasis, attentionAstString)
+	attentionParagraph.AppendChild(attentionParagraph, NewAttention(attentionType))
+	attentionParagraph.AppendChild(attentionParagraph, emphasis)
+	firstParagraph.Parent().InsertBefore(firstParagraph.Parent(), firstParagraph, attentionParagraph)
+	firstParagraph.RemoveChild(firstParagraph, node1)
+	firstParagraph.RemoveChild(firstParagraph, node2)
+	firstParagraph.RemoveChild(firstParagraph, node3)
+	if firstParagraph.ChildCount() == 0 {
+		firstParagraph.Parent().RemoveChild(firstParagraph.Parent(), firstParagraph)
+	}
+	return ast.WalkContinue, nil
+}