Split sanitizer functions and fine-tune some tests (#31192)

modules/markup/sanitizer_description.go

@@ -0,0 +1,37 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markup
+
+import (
+	"regexp"
+
+	"github.com/microcosm-cc/bluemonday"
+)
+
+// createRepoDescriptionPolicy returns a minimal more strict policy that is used for
+// repository descriptions.
+func (st *Sanitizer) createRepoDescriptionPolicy() *bluemonday.Policy {
+	policy := bluemonday.NewPolicy()
+	policy.AllowStandardURLs()
+
+	// Allow italics and bold.
+	policy.AllowElements("i", "b", "em", "strong")
+
+	// Allow code.
+	policy.AllowElements("code")
+
+	// Allow links
+	policy.AllowAttrs("href", "target", "rel").OnElements("a")
+
+	// Allow classes for emojis
+	policy.AllowAttrs("class").Matching(regexp.MustCompile(`^emoji$`)).OnElements("img", "span")
+	policy.AllowAttrs("aria-label").OnElements("span")
+
+	return policy
+}
+
+// SanitizeDescription sanitizes the HTML generated for a repository description.
+func SanitizeDescription(s string) string {
+	return GetDefaultSanitizer().descriptionPolicy.Sanitize(s)
+}