tests: Markdown alert block test cases

This adds a few test cases to exercise the alert block feature of the
markdown renderer, both the legacy GitHub style, and the modern one.

Signed-off-by: Gergely Nagy <forgejo@gergo.csillger.hu>

tests/integration/markup_test.go

@@ -0,0 +1,72 @@
+// Copyright 2024 The Forgejo Authors c/o Codeberg e.V.. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package integration
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+	"testing"
+
+	auth_model "code.gitea.io/gitea/models/auth"
+	api "code.gitea.io/gitea/modules/structs"
+	"code.gitea.io/gitea/tests"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRenderAlertBlocks(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	session := loginUser(t, "user1")
+	token := getTokenForLoggedInUser(t, session, auth_model.AccessTokenScopeWriteMisc)
+
+	assertAlertBlock := func(t *testing.T, input, alertType, alertIcon string) {
+		t.Helper()
+
+		blockquoteAttr := fmt.Sprintf(`<blockquote class="gt-py-3 attention attention-%s"`, strings.ToLower(alertType))
+		classAttr := fmt.Sprintf(`class="attention-%s"`, strings.ToLower(alertType))
+		iconAttr := fmt.Sprintf(`class="svg octicon-%s"`, alertIcon)
+
+		req := NewRequestWithJSON(t, "POST", "/api/v1/markdown", &api.MarkdownOption{
+			Text: input,
+			Mode: "markdown",
+		}).AddTokenAuth(token)
+		resp := MakeRequest(t, req, http.StatusOK)
+		body := resp.Body.String()
+		assert.Contains(t, body, blockquoteAttr)
+		assert.Contains(t, body, classAttr)
+		assert.Contains(t, body, iconAttr)
+	}
+
+	t.Run("legacy style", func(t *testing.T) {
+		for alertType, alertIcon := range map[string]string{"Note": "info", "Warning": "alert"} {
+			t.Run(alertType, func(t *testing.T) {
+				input := fmt.Sprintf(`> **%s**
+>
+> This is a %s.`, alertType, alertType)
+
+				assertAlertBlock(t, input, alertType, alertIcon)
+			})
+		}
+	})
+
+	t.Run("modern style", func(t *testing.T) {
+		for alertType, alertIcon := range map[string]string{
+			"NOTE":      "info",
+			"TIP":       "light-bulb",
+			"IMPORTANT": "report",
+			"WARNING":   "alert",
+			"CAUTION":   "stop",
+		} {
+			t.Run(alertType, func(t *testing.T) {
+				input := fmt.Sprintf(`> [!%s]
+>
+> This is a %s.`, alertType, alertType)
+
+				assertAlertBlock(t, input, alertType, alertIcon)
+			})
+		}
+	})
+}