Add API for Label templates (#24602)

This adds API that allows getting the Label templates of the Gitea
Instance

tests/integration/api_label_templates_test.go

@@ -0,0 +1,61 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package integration
+
+import (
+	"fmt"
+	"net/http"
+	"net/url"
+	"strings"
+	"testing"
+
+	repo_module "code.gitea.io/gitea/modules/repository"
+	api "code.gitea.io/gitea/modules/structs"
+	"code.gitea.io/gitea/tests"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestAPIListLabelTemplates(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	req := NewRequest(t, "GET", "/api/v1/label/templates")
+	resp := MakeRequest(t, req, http.StatusOK)
+
+	var templateList []string
+	DecodeJSON(t, resp, &templateList)
+
+	for i := range repo_module.LabelTemplateFiles {
+		assert.Equal(t, repo_module.LabelTemplateFiles[i].DisplayName, templateList[i])
+	}
+}
+
+func TestAPIGetLabelTemplateInfo(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	// If Gitea has for some reason no Label templates, we need to skip this test
+	if len(repo_module.LabelTemplateFiles) == 0 {
+		return
+	}
+
+	// Use the first template for the test
+	templateName := repo_module.LabelTemplateFiles[0].DisplayName
+
+	urlStr := fmt.Sprintf("/api/v1/label/templates/%s", url.PathEscape(templateName))
+	req := NewRequest(t, "GET", urlStr)
+	resp := MakeRequest(t, req, http.StatusOK)
+
+	var templateInfo []api.LabelTemplate
+	DecodeJSON(t, resp, &templateInfo)
+
+	labels, err := repo_module.LoadTemplateLabelsByDisplayName(templateName)
+	assert.NoError(t, err)
+
+	for i := range labels {
+		assert.Equal(t, strings.TrimLeft(labels[i].Color, "#"), templateInfo[i].Color)
+		assert.Equal(t, labels[i].Description, templateInfo[i].Description)
+		assert.Equal(t, labels[i].Exclusive, templateInfo[i].Exclusive)
+		assert.Equal(t, labels[i].Name, templateInfo[i].Name)
+	}
+}