Refactor render system (#32492)

There were too many patches to the Render system, it's really difficult
to make further improvements.

This PR clears the legacy problems and fix TODOs.

1. Rename `RenderContext.Type` to `RenderContext.MarkupType` to clarify
its usage.
2. Use `ContentMode` to replace `meta["mode"]` and `IsWiki`, to clarify
the rendering behaviors.
3. Use "wiki" mode instead of "mode=gfm + wiki=true"
4. Merge `renderByType` and `renderByFile`
5. Add more comments

----

The problem of "mode=document": in many cases it is not set, so many
non-comment places use comment's hard line break incorrectly

modules/markup/markdown/goldmark.go

@@ -72,7 +72,12 @@ func (g *ASTTransformer) Transform(node *ast.Document, reader text.Reader, pc pa
 			g.transformList(ctx, v, rc)
 		case *ast.Text:
 			if v.SoftLineBreak() && !v.HardLineBreak() {
-				if ctx.Metas["mode"] != "document" {
+				// TODO: this was a quite unclear part, old code: `if metas["mode"] != "document" { use comment link break setting }`
+				// many places render non-comment contents with no mode=document, then these contents also use comment's hard line break setting
+				// especially in many tests.
+				if markup.RenderBehaviorForTesting.ForceHardLineBreak {
+					v.SetHardLineBreak(true)
+				} else if ctx.ContentMode == markup.RenderContentAsComment {
 					v.SetHardLineBreak(setting.Markdown.EnableHardLineBreakInComments)
 				} else {
 					v.SetHardLineBreak(setting.Markdown.EnableHardLineBreakInDocuments)

modules/markup/markdown/markdown.go

@@ -257,9 +257,7 @@ func (Renderer) Render(ctx *markup.RenderContext, input io.Reader, output io.Wri
 
 // Render renders Markdown to HTML with all specific handling stuff.
 func Render(ctx *markup.RenderContext, input io.Reader, output io.Writer) error {
-	if ctx.Type == "" {
-		ctx.Type = MarkupName
-	}
+	ctx.MarkupType = MarkupName
 	return markup.Render(ctx, input, output)
 }
 

modules/markup/markdown/markdown_test.go

@@ -16,6 +16,7 @@ import (
 	"code.gitea.io/gitea/modules/markup/markdown"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/svg"
+	"code.gitea.io/gitea/modules/test"
 	"code.gitea.io/gitea/modules/util"
 
 	"github.com/stretchr/testify/assert"
@@ -74,7 +75,7 @@ func TestRender_StandardLinks(t *testing.T) {
 			Links: markup.Links{
 				Base: FullURL,
 			},
-			IsWiki: true,
+			ContentMode: markup.RenderContentAsWiki,
 		}, input)
 		assert.NoError(t, err)
 		assert.Equal(t, strings.TrimSpace(expectedWiki), strings.TrimSpace(string(buffer)))
@@ -296,23 +297,22 @@ This PR has been generated by [Renovate Bot](https://github.com/renovatebot/reno
 }
 
 func TestTotal_RenderWiki(t *testing.T) {
+	defer test.MockVariableValue(&markup.RenderBehaviorForTesting.ForceHardLineBreak, true)()
+	defer test.MockVariableValue(&markup.RenderBehaviorForTesting.DisableInternalAttributes, true)()
 	setting.AppURL = AppURL
-
 	answers := testAnswers(util.URLJoin(FullURL, "wiki"), util.URLJoin(FullURL, "wiki", "raw"))
-
 	for i := 0; i < len(sameCases); i++ {
 		line, err := markdown.RenderString(&markup.RenderContext{
 			Ctx: git.DefaultContext,
 			Links: markup.Links{
 				Base: FullURL,
 			},
-			Repo:   newMockRepo(testRepoOwnerName, testRepoName),
-			Metas:  localMetas,
-			IsWiki: true,
+			Repo:        newMockRepo(testRepoOwnerName, testRepoName),
+			Metas:       localMetas,
+			ContentMode: markup.RenderContentAsWiki,
 		}, sameCases[i])
 		assert.NoError(t, err)
-		actual := strings.ReplaceAll(string(line), ` data-markdown-generated-content=""`, "")
-		assert.Equal(t, answers[i], actual)
+		assert.Equal(t, answers[i], string(line))
 	}
 
 	testCases := []string{
@@ -334,19 +334,18 @@ func TestTotal_RenderWiki(t *testing.T) {
 			Links: markup.Links{
 				Base: FullURL,
 			},
-			IsWiki: true,
+			ContentMode: markup.RenderContentAsWiki,
 		}, testCases[i])
 		assert.NoError(t, err)
-		actual := strings.ReplaceAll(string(line), ` data-markdown-generated-content=""`, "")
-		assert.EqualValues(t, testCases[i+1], actual)
+		assert.EqualValues(t, testCases[i+1], string(line))
 	}
 }
 
 func TestTotal_RenderString(t *testing.T) {
+	defer test.MockVariableValue(&markup.RenderBehaviorForTesting.ForceHardLineBreak, true)()
+	defer test.MockVariableValue(&markup.RenderBehaviorForTesting.DisableInternalAttributes, true)()
 	setting.AppURL = AppURL
-
 	answers := testAnswers(util.URLJoin(FullURL, "src", "master"), util.URLJoin(FullURL, "media", "master"))
-
 	for i := 0; i < len(sameCases); i++ {
 		line, err := markdown.RenderString(&markup.RenderContext{
 			Ctx: git.DefaultContext,
@@ -358,8 +357,7 @@ func TestTotal_RenderString(t *testing.T) {
 			Metas: localMetas,
 		}, sameCases[i])
 		assert.NoError(t, err)
-		actual := strings.ReplaceAll(string(line), ` data-markdown-generated-content=""`, "")
-		assert.Equal(t, answers[i], actual)
+		assert.Equal(t, answers[i], string(line))
 	}
 
 	testCases := []string{}
@@ -428,6 +426,7 @@ func TestRenderSiblingImages_Issue12925(t *testing.T) {
 	expected := `<p><a href="/image1" target="_blank" rel="nofollow noopener"><img src="/image1" alt="image1"></a><br>
 <a href="/image2" target="_blank" rel="nofollow noopener"><img src="/image2" alt="image2"></a></p>
 `
+	defer test.MockVariableValue(&markup.RenderBehaviorForTesting.ForceHardLineBreak, true)()
 	res, err := markdown.RenderRawString(&markup.RenderContext{Ctx: git.DefaultContext}, testcase)
 	assert.NoError(t, err)
 	assert.Equal(t, expected, res)
@@ -996,11 +995,16 @@ space</p>
 		},
 	}
 
+	defer test.MockVariableValue(&markup.RenderBehaviorForTesting.ForceHardLineBreak, true)()
+	defer test.MockVariableValue(&markup.RenderBehaviorForTesting.DisableInternalAttributes, true)()
 	for i, c := range cases {
-		result, err := markdown.RenderString(&markup.RenderContext{Ctx: context.Background(), Links: c.Links, IsWiki: c.IsWiki}, input)
+		result, err := markdown.RenderString(&markup.RenderContext{
+			Ctx:         context.Background(),
+			Links:       c.Links,
+			ContentMode: util.Iif(c.IsWiki, markup.RenderContentAsWiki, markup.RenderContentAsDefault),
+		}, input)
 		assert.NoError(t, err, "Unexpected error in testcase: %v", i)
-		actual := strings.ReplaceAll(string(result), ` data-markdown-generated-content=""`, "")
-		assert.Equal(t, c.Expected, actual, "Unexpected result in testcase %v", i)
+		assert.Equal(t, c.Expected, string(result), "Unexpected result in testcase %v", i)
 	}
 }
 

modules/markup/markdown/transform_image.go

@@ -21,7 +21,7 @@ func (g *ASTTransformer) transformImage(ctx *markup.RenderContext, v *ast.Image)
 	// Check if the destination is a real link
 	if len(v.Destination) > 0 && !markup.IsFullURLBytes(v.Destination) {
 		v.Destination = []byte(giteautil.URLJoin(
-			ctx.Links.ResolveMediaLink(ctx.IsWiki),
+			ctx.Links.ResolveMediaLink(ctx.ContentMode == markup.RenderContentAsWiki),
 			strings.TrimLeft(string(v.Destination), "/"),
 		))
 	}