Growth spike: Get latest MM version (#19366)

* tools updates

* Revert "tools updates"

This reverts commit 6293297b55803c5a263e200ebd80192899666ae9.

* new endpoint to fetch the latest release information

* adding unit tests

* fixing tests and adding check for github response

* error translations

* fixing translations

* chaning error log

* changing cache size

* empty strings for translations

* changing size to 1

Co-authored-by: Benjamin Cooke <benjamincooke@Benjamins-MacBook-Pro.local>
Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

app/admin_test.go

@@ -0,0 +1,91 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package app
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/mattermost/mattermost-server/v6/model"
+)
+
+func TestGetLatestVersion(t *testing.T) {
+	th := Setup(t).InitBasic()
+	defer th.TearDown()
+
+	version := &model.GithubReleaseInfo{
+		Id:          57117096,
+		TagName:     "v6.3.0",
+		Name:        "v6.3.0",
+		CreatedAt:   "2022-01-13T14:19:44Z",
+		PublishedAt: "2022-01-14T13:45:09Z",
+		Body:        "Mattermost Platform Release v6.3.0",
+		Url:         "https://github.com/mattermost/mattermost-server/releases/tag/v6.3.0",
+	}
+
+	validJSON, jsonErr := json.Marshal(version)
+	require.NoError(t, jsonErr)
+
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Write(validJSON)
+	}))
+	defer ts.Close()
+
+	t.Run("get latest mm version happy path", func(t *testing.T) {
+		_, err := th.App.GetLatestVersion(ts.URL)
+		require.Nil(t, err)
+	})
+
+	t.Run("get latest mm version from cache", func(t *testing.T) {
+		th.App.ClearLatestVersionCache()
+		originalResult, err := th.App.GetLatestVersion(ts.URL)
+		require.Nil(t, err)
+
+		// Call same function but mock the GET request to return a different result.
+		// We are hoping the function will use the cache instead of making the GET request
+		v := &model.GithubReleaseInfo{
+			Id:          57117096,
+			TagName:     "v6.3.1",
+			Name:        "v6.3.1",
+			CreatedAt:   "2022-01-13T14:19:44Z",
+			PublishedAt: "2022-01-14T13:45:09Z",
+			Body:        "Mattermost Platform Release v6.3.0",
+			Url:         "https://github.com/mattermost/mattermost-server/releases/tag/v6.3.0",
+		}
+
+		updatedJSON, jsonErr := json.Marshal(v)
+		require.NoError(t, jsonErr)
+
+		updatedServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.Write(updatedJSON)
+		}))
+		defer ts.Close()
+
+		cachedResult, err := th.App.GetLatestVersion(updatedServer.URL)
+		require.Nil(t, err)
+
+		require.Equal(t, originalResult.TagName, cachedResult.TagName, "did not get cached result")
+	})
+
+	t.Run("get latest mm version error from external", func(t *testing.T) {
+		th.App.ClearLatestVersionCache()
+		errorServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.WriteHeader(http.StatusInternalServerError)
+			w.Write([]byte(`
+				{
+					"message": "internal server error"
+				}
+			`))
+		}))
+		defer ts.Close()
+
+		_, err := th.App.GetLatestVersion(errorServer.URL)
+		require.NotNil(t, err)
+		require.Equal(t, "app.admin.latest_version_external_error.failure", err.Id)
+	})
+}