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

2 files changed, 12 insertions, 13 deletions

diff --git a/routers/api/v1/misc/markup.go b/routers/api/v1/misc/markup.go
index 9699c79368..868ed92519 100644
--- a/routers/api/v1/misc/markup.go
+++ b/routers/api/v1/misc/markup.go
@@ -9,6 +9,7 @@ import (
 	"code.gitea.io/gitea/modules/markup"
 	"code.gitea.io/gitea/modules/markup/markdown"
 	api "code.gitea.io/gitea/modules/structs"
+	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/modules/web"
 	"code.gitea.io/gitea/routers/common"
 	"code.gitea.io/gitea/services/context"
@@ -41,7 +42,8 @@ func Markup(ctx *context.APIContext) {
 		return
 	}
 
-	common.RenderMarkup(ctx.Base, ctx.Repo, form.Mode, form.Text, form.Context, form.FilePath, form.Wiki)
+	mode := util.Iif(form.Wiki, "wiki", form.Mode) //nolint:staticcheck
+	common.RenderMarkup(ctx.Base, ctx.Repo, mode, form.Text, form.Context, form.FilePath)
 }
 
 // Markdown render markdown document to HTML
@@ -71,12 +73,8 @@ func Markdown(ctx *context.APIContext) {
 		return
 	}
 
-	mode := "markdown"
-	if form.Mode == "comment" || form.Mode == "gfm" {
-		mode = form.Mode
-	}
-
-	common.RenderMarkup(ctx.Base, ctx.Repo, mode, form.Text, form.Context, "", form.Wiki)
+	mode := util.Iif(form.Wiki, "wiki", form.Mode) //nolint:staticcheck
+	common.RenderMarkup(ctx.Base, ctx.Repo, mode, form.Text, form.Context, "")
 }
 
 // MarkdownRaw render raw markdown HTML
diff --git a/routers/api/v1/misc/markup_test.go b/routers/api/v1/misc/markup_test.go
index abffdf3516..6b8c09034a 100644
--- a/routers/api/v1/misc/markup_test.go
+++ b/routers/api/v1/misc/markup_test.go
@@ -14,6 +14,7 @@ import (
 	"code.gitea.io/gitea/modules/markup"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
+	"code.gitea.io/gitea/modules/test"
 	"code.gitea.io/gitea/modules/web"
 	"code.gitea.io/gitea/services/contexttest"
 
@@ -24,6 +25,7 @@ const AppURL = "http://localhost:3000/"
 
 func testRenderMarkup(t *testing.T, mode string, wiki bool, filePath, text, expectedBody string, expectedCode int) {
 	setting.AppURL = AppURL
+	defer test.MockVariableValue(&markup.RenderBehaviorForTesting.DisableInternalAttributes, true)()
 	context := "/gogits/gogs"
 	if !wiki {
 		context += path.Join("/src/branch/main", path.Dir(filePath))
@@ -38,13 +40,13 @@ func testRenderMarkup(t *testing.T, mode string, wiki bool, filePath, text, expe
 	ctx, resp := contexttest.MockAPIContext(t, "POST /api/v1/markup")
 	web.SetForm(ctx, &options)
 	Markup(ctx)
-	actual := strings.ReplaceAll(resp.Body.String(), ` data-markdown-generated-content=""`, "")
-	assert.Equal(t, expectedBody, actual)
+	assert.Equal(t, expectedBody, resp.Body.String())
 	assert.Equal(t, expectedCode, resp.Code)
 	resp.Body.Reset()
 }
 
 func testRenderMarkdown(t *testing.T, mode string, wiki bool, text, responseBody string, responseCode int) {
+	defer test.MockVariableValue(&markup.RenderBehaviorForTesting.DisableInternalAttributes, true)()
 	setting.AppURL = AppURL
 	context := "/gogits/gogs"
 	if !wiki {
@@ -59,8 +61,7 @@ func testRenderMarkdown(t *testing.T, mode string, wiki bool, text, responseBody
 	ctx, resp := contexttest.MockAPIContext(t, "POST /api/v1/markdown")
 	web.SetForm(ctx, &options)
 	Markdown(ctx)
-	actual := strings.ReplaceAll(resp.Body.String(), ` data-markdown-generated-content=""`, "")
-	assert.Equal(t, responseBody, actual)
+	assert.Equal(t, responseBody, resp.Body.String())
 	assert.Equal(t, responseCode, resp.Code)
 	resp.Body.Reset()
 }
@@ -158,8 +159,8 @@ Here are some links to the most important topics. You can find the full list of
 <a href="http://localhost:3000/gogits/gogs/media/branch/main/path/image.png" target="_blank" rel="nofollow noopener"><img src="http://localhost:3000/gogits/gogs/media/branch/main/path/image.png" alt="Image"/></a></p>
 `, http.StatusOK)
 
-	testRenderMarkup(t, "file", true, "path/test.unknown", "## Test", "Unsupported render extension: .unknown\n", http.StatusUnprocessableEntity)
-	testRenderMarkup(t, "unknown", true, "", "## Test", "Unknown mode: unknown\n", http.StatusUnprocessableEntity)
+	testRenderMarkup(t, "file", false, "path/test.unknown", "## Test", "unsupported file to render: \"path/test.unknown\"\n", http.StatusUnprocessableEntity)
+	testRenderMarkup(t, "unknown", false, "", "## Test", "Unknown mode: unknown\n", http.StatusUnprocessableEntity)
 }
 
 var simpleCases = []string{