feat(backend): establish gin sqlite service skeleton

backend-api/cmd/api/main_test.go

@@ -0,0 +1,75 @@
+package main
+
+import (
+	"errors"
+	"net"
+	"net/http"
+	"testing"
+	"time"
+)
+
+func TestShutdownServerForceClosesAfterGracefulTimeout(t *testing.T) {
+	handlerStarted := make(chan struct{})
+	releaseHandler := make(chan struct{})
+	server := &http.Server{
+		Handler: http.HandlerFunc(func(http.ResponseWriter, *http.Request) {
+			close(handlerStarted)
+			<-releaseHandler
+		}),
+		ReadHeaderTimeout: time.Second,
+	}
+	listener, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatalf("net.Listen() error = %v", err)
+	}
+	serverErrors := make(chan error, 1)
+	go func() {
+		serverErrors <- server.Serve(listener)
+	}()
+
+	requestFinished := make(chan struct{})
+	go func() {
+		defer close(requestFinished)
+		client := http.Client{Timeout: time.Second}
+		response, err := client.Get("http://" + listener.Addr().String())
+		if err == nil {
+			_ = response.Body.Close()
+		}
+	}()
+	select {
+	case <-handlerStarted:
+	case <-time.After(time.Second):
+		t.Fatal("handler did not start")
+	}
+
+	err = shutdownServer(server, serverErrors, 10*time.Millisecond)
+	if err == nil {
+		t.Fatal("shutdownServer() error = nil")
+	}
+	close(releaseHandler)
+	select {
+	case <-requestFinished:
+	case <-time.After(time.Second):
+		t.Fatal("request did not finish after force close")
+	}
+	connection, dialErr := net.DialTimeout(
+		"tcp",
+		listener.Addr().String(),
+		100*time.Millisecond,
+	)
+	if dialErr == nil {
+		_ = connection.Close()
+		t.Fatal("listener still accepted connections after force close")
+	}
+}
+
+func TestShutdownServerAcceptsNormalServerClose(t *testing.T) {
+	serverErrors := make(chan error, 1)
+	serverErrors <- http.ErrServerClosed
+	server := &http.Server{}
+
+	if err := shutdownServer(server, serverErrors, time.Second); err != nil &&
+		!errors.Is(err, http.ErrServerClosed) {
+		t.Fatalf("shutdownServer() error = %v", err)
+	}
+}