Add API for License templates (#23009)

This adds a API for getting License templates. This tries to be as close
to the [GitHub
API](https://docs.github.com/en/rest/licenses?apiVersion=2022-11-28) as
possible, but Gitea does not support all features that GitHub has. I
think they should been added, but this out f the scope of this PR. You
should merge #23006 before this PR for security reasons.

1 files changed, 55 insertions, 0 deletions

diff --git a/tests/integration/api_license_templates_test.go b/tests/integration/api_license_templates_test.go
new file mode 100644
index 0000000000..e12aab7c2c
--- /dev/null
+++ b/tests/integration/api_license_templates_test.go
@@ -0,0 +1,55 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package integration
+
+import (
+	"fmt"
+	"net/http"
+	"net/url"
+	"testing"
+
+	"code.gitea.io/gitea/modules/options"
+	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 TestAPIListLicenseTemplates(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	req := NewRequest(t, "GET", "/api/v1/licenses")
+	resp := MakeRequest(t, req, http.StatusOK)
+
+	// This tests if the API returns a list of strings
+	var licenseList []api.LicensesTemplateListEntry
+	DecodeJSON(t, resp, &licenseList)
+}
+
+func TestAPIGetLicenseTemplateInfo(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	// If Gitea has for some reason no License templates, we need to skip this test
+	if len(repo_module.Licenses) == 0 {
+		return
+	}
+
+	// Use the first template for the test
+	licenseName := repo_module.Licenses[0]
+
+	urlStr := fmt.Sprintf("/api/v1/licenses/%s", url.PathEscape(licenseName))
+	req := NewRequest(t, "GET", urlStr)
+	resp := MakeRequest(t, req, http.StatusOK)
+
+	var licenseInfo api.LicenseTemplateInfo
+	DecodeJSON(t, resp, &licenseInfo)
+
+	// We get the text of the template here
+	text, _ := options.License(licenseName)
+
+	assert.Equal(t, licenseInfo.Key, licenseName)
+	assert.Equal(t, licenseInfo.Name, licenseName)
+	assert.Equal(t, licenseInfo.Body, string(text))
+}