feat: add tests

internal/server/backendinfo/service_test.go

@@ -0,0 +1,193 @@
+package backendinfo
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+	"github.com/x1unix/go-playground/pkg/goplay"
+	"github.com/x1unix/go-playground/pkg/testutil"
+)
+
+func TestBackendVersionService_ServerVersion(t *testing.T) {
+	want := strings.TrimPrefix(runtime.Version(), "go")
+
+	svc := NewBackendVersionService(nil, nil, ServiceConfig{})
+	got := svc.ServerVersion()
+	require.Equal(t, got, want)
+}
+
+func TestBackendVersionService_GetRemoteVersions(t *testing.T) {
+	cases := map[string]struct{
+		constructor func(t *testing.T, expect BackendVersions) *BackendVersionService
+		onPostRun func(t *testing.T, svc *BackendVersionService, expect BackendVersions)
+		expect BackendVersions
+		expectErr string
+	}{
+		"should use ram cache": {
+			expect: BackendVersions{
+				CurrentStable:  "1.23",
+				PreviousStable: "1.22",
+				Nightly:        "test",
+			},
+			constructor: func(t *testing.T, expect BackendVersions) *BackendVersionService {
+				svc := NewBackendVersionService(nil, nil, ServiceConfig{TTL: DefaultVersionCacheTTL})
+				svc.memCache = &cacheEntry{
+					Version:   cacheFileVersion,
+					CreatedAt: time.Now(),
+					Data:      expect,
+				}
+				return svc
+			},
+		},
+		"should fallback to filesystem cache": {
+			expect: BackendVersions{
+				CurrentStable:  "1",
+				PreviousStable: "2",
+				Nightly:        "test",
+			},
+			constructor: func(t *testing.T, expect BackendVersions) *BackendVersionService {
+				fname := writeTestJson(t, "cache.json", cacheEntry{
+					CreatedAt: time.Now(),
+					Version: cacheFileVersion,
+					Data: expect,
+				})
+				svc := NewBackendVersionService(nil, nil, ServiceConfig{
+					TTL: DefaultVersionCacheTTL,
+					CacheFile: fname,
+				})
+
+				return svc
+			},
+		},
+		"should fetch data if not cached": {
+			expect: BackendVersions{
+				CurrentStable:  "1",
+				PreviousStable: "2",
+				Nightly:        "test",
+			},
+			constructor: func(t *testing.T, expect BackendVersions) *BackendVersionService {
+				fname := filepath.Join(t.TempDir(), "test", "store.json")
+				srv := setupTestServer(expect)
+				logger := testutil.GetLogger(t).Desugar()
+				c := goplay.NewClient(srv.URL, "", 5 * time.Second)
+
+				svc := NewBackendVersionService(logger, c, ServiceConfig{
+					TTL: DefaultVersionCacheTTL,
+					CacheFile: fname,
+				})
+
+				return svc
+			},
+			onPostRun: func(t *testing.T, svc *BackendVersionService, expect BackendVersions) {
+				f, err := os.Open(svc.cfg.CacheFile)
+				require.NoError(t, err)
+				defer f.Close()
+
+				dst := &cacheEntry{}
+				err = json.NewDecoder(f).Decode(dst)
+				require.Equal(t, expect, dst.Data)
+			},
+		},
+		"should fetch data on cache miss": {
+			expect: BackendVersions{
+				CurrentStable:  "1",
+				PreviousStable: "2",
+				Nightly:        "test",
+			},
+			constructor: func(t *testing.T, expect BackendVersions) *BackendVersionService {
+				fname := writeTestJson(t, "cache.json", cacheEntry{
+					CreatedAt: time.Now().Add(-30 * time.Hour),
+					Version: cacheFileVersion,
+				})
+
+				srv := setupTestServer(expect)
+				logger := testutil.GetLogger(t).Desugar()
+				c := goplay.NewClient(srv.URL, "", 5 * time.Second)
+
+				svc := NewBackendVersionService(logger, c, ServiceConfig{
+					TTL: time.Hour,
+					CacheFile: fname,
+				})
+
+				return svc
+			},
+			onPostRun: func(t *testing.T, svc *BackendVersionService, expect BackendVersions) {
+				f, err := os.Open(svc.cfg.CacheFile)
+				require.NoError(t, err)
+				defer f.Close()
+
+				dst := &cacheEntry{}
+				err = json.NewDecoder(f).Decode(dst)
+				require.Equal(t, expect, dst.Data)
+			},
+		},
+	}
+
+	for n, c := range cases {
+		t.Run(n, func(t *testing.T) {
+			if c.constructor == nil {
+				t.Fatal("missing constructor")
+			}
+
+			svc := c.constructor(t, c.expect)
+			got, err := svc.GetRemoteVersions(context.TODO())
+			if c.expectErr != "" {
+				require.Error(t, err)
+				require.EqualError(t, err, c.expectErr)
+				return
+			}
+
+			require.NoError(t, err)
+			require.NotNil(t, got)
+			require.Equal(t, *got, c.expect)
+		})
+	}
+}
+
+func writeTestJson(t *testing.T, name string, data any) string {
+	fname := filepath.Join(t.TempDir(), name)
+	f, err := os.OpenFile(fname, os.O_RDWR | os.O_CREATE | os.O_TRUNC, 0644)	
+	require.NoError(t, err, "can't create test file")
+
+	err = json.NewEncoder(f).Encode(data)
+	_ = f.Close()
+
+	require.NoError(t, err, "can't wrote to a test file")
+	return fname
+}
+
+func setupTestServer(expects BackendVersions) *httptest.Server {
+	return httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		var msg string
+		switch r.URL.Query().Get("backend") {
+		case goplay.BackendGoPrev:
+			msg = expects.PreviousStable
+		case goplay.BackendGoTip:
+			msg = expects.Nightly
+		case goplay.BackendGoCurrent:
+			msg = expects.CurrentStable
+		}
+
+		rsp := goplay.CompileResponse{
+			Events: []*goplay.CompileEvent{
+				{
+					Kind: "stdout",
+					Message: msg,
+				},
+			},
+		}
+
+		w.Header().Set("Content-Type", "application/json")
+		_ = json.NewEncoder(w).Encode(rsp)
+	}))
+}
+