feat: add Go migration compatibility foundation

backend/internal/application/application.go

@@ -0,0 +1,79 @@
+// Package application composes the Go backend foundation Modules.
+package application
+
+import (
+	"context"
+	"net/http"
+	"os"
+
+	"git.nianxx.cn/wangxuming/NianAIGC/backend/internal/httpapi"
+	"git.nianxx.cn/wangxuming/NianAIGC/backend/internal/postgres"
+)
+
+type Options struct {
+	Context  context.Context
+	Getenv   postgres.Getenv
+	ReadFile postgres.ReadFile
+}
+
+type App struct {
+	handler http.Handler
+	db      *postgres.Module
+}
+
+func New(options Options) (*App, error) {
+	ctx := options.Context
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	getenv := options.Getenv
+	if getenv == nil {
+		getenv = os.Getenv
+	}
+	readFile := options.ReadFile
+	if readFile == nil {
+		readFile = os.ReadFile
+	}
+
+	config, err := postgres.ParseConfig(getenv, readFile)
+	if err != nil {
+		return nil, err
+	}
+	database, err := postgres.Open(ctx, config)
+	if err != nil {
+		return nil, err
+	}
+	readiness := databaseReadiness{config: config, store: database.Store}
+	return &App{
+		db:      database,
+		handler: httpapi.NewHandler(readiness),
+	}, nil
+}
+
+func (app *App) Handler() http.Handler {
+	return app.handler
+}
+
+func (app *App) Close() {
+	if app.db != nil {
+		app.db.Close()
+	}
+}
+
+type databaseReadiness struct {
+	config postgres.Config
+	store  *postgres.Store
+}
+
+func (adapter databaseReadiness) Status() httpapi.DatabaseStatus {
+	configured := adapter.config.Backend == postgres.BackendLocal || adapter.config.DatabaseURL != ""
+	return httpapi.DatabaseStatus{
+		Backend:    string(adapter.config.Backend),
+		Configured: configured,
+	}
+}
+
+func (adapter databaseReadiness) Ready(ctx context.Context) (httpapi.DatabaseStatus, error) {
+	status := adapter.Status()
+	return status, adapter.store.Readiness(ctx)
+}

backend/internal/application/application_test.go

@@ -0,0 +1,68 @@
+package application_test
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"git.nianxx.cn/wangxuming/NianAIGC/backend/internal/application"
+)
+
+func TestLocalApplicationServesFoundationHealthAndReadiness(t *testing.T) {
+	app, err := application.New(application.Options{
+		Getenv: func(name string) string {
+			if name == "ZHINIAN_DATA_BACKEND" {
+				return "local"
+			}
+			return ""
+		},
+	})
+	if err != nil {
+		t.Fatalf("New() error = %v", err)
+	}
+	t.Cleanup(app.Close)
+
+	for _, test := range []struct {
+		path     string
+		wantCode int
+	}{
+		{path: "/api/health", wantCode: http.StatusOK},
+		{path: "/api/ready", wantCode: http.StatusOK},
+	} {
+		t.Run(test.path, func(t *testing.T) {
+			response := httptest.NewRecorder()
+			app.Handler().ServeHTTP(response, httptest.NewRequest(http.MethodGet, test.path, nil))
+			if response.Code != test.wantCode {
+				t.Fatalf("status = %d, want %d", response.Code, test.wantCode)
+			}
+			var payload struct {
+				OK       bool `json:"ok"`
+				Database struct {
+					Backend    string `json:"backend"`
+					Configured bool   `json:"configured"`
+				} `json:"database"`
+			}
+			if err := json.NewDecoder(response.Body).Decode(&payload); err != nil {
+				t.Fatalf("decode response: %v", err)
+			}
+			if !payload.OK || payload.Database.Backend != "local" || !payload.Database.Configured {
+				t.Fatalf("payload = %+v", payload)
+			}
+		})
+	}
+}
+
+func TestApplicationRejectsInvalidProductionDatabaseConfiguration(t *testing.T) {
+	_, err := application.New(application.Options{
+		Getenv: func(name string) string {
+			if name == "NODE_ENV" {
+				return "production"
+			}
+			return ""
+		},
+	})
+	if err == nil {
+		t.Fatal("New() error = nil, want fail-closed database configuration error")
+	}
+}