Organize backend into product executable and shared Go modules

backend/product/auth/client/client.go

@@ -0,0 +1,29 @@
+package client
+
+import (
+	"context"
+	"errors"
+	sessionmodel "git.sendico.io/tech/sxchnge/product/sessions/model"
+	"strings"
+
+	"git.sendico.io/tech/sxchnge/product/sessions/store"
+	"git.sendico.io/tech/sxchnge/shared/errors"
+)
+
+var ErrUnknownClientID = merrors.Define("unknown client id")
+
+func Resolve(ctx context.Context, rtdb refreshtokens.DB, clientID string) (*sessionmodel.Client, error) {
+	clientID = strings.TrimSpace(clientID)
+	if clientID == "" {
+		return nil, ErrUnknownClientID
+	}
+
+	client, err := rtdb.GetClient(ctx, clientID)
+	if errors.Is(err, merrors.ErrNoData) || client == nil {
+		return nil, ErrUnknownClientID
+	}
+	if err != nil {
+		return nil, err
+	}
+	return client, nil
+}

backend/product/auth/client/client_test.go

@@ -0,0 +1,53 @@
+package client
+
+import (
+	"context"
+	"errors"
+	sessionmodel "git.sendico.io/tech/sxchnge/product/sessions/model"
+	"testing"
+
+	"git.sendico.io/tech/sxchnge/product/sessions/store"
+)
+
+type resolveClientDB struct {
+	refreshtokens.DB
+	calls  int
+	client *sessionmodel.Client
+	err    error
+}
+
+func (db *resolveClientDB) GetClient(ctx context.Context, clientID string) (*sessionmodel.Client, error) {
+	db.calls++
+	return db.client, db.err
+}
+
+func TestResolveRejectsBlankClientIDWithoutStorageLookup(t *testing.T) {
+	db := &resolveClientDB{}
+
+	client, err := Resolve(context.Background(), db, "  ")
+	if !errors.Is(err, ErrUnknownClientID) {
+		t.Fatalf("expected unknown client id, got %v", err)
+	}
+	if client != nil {
+		t.Fatalf("expected nil client, got %#v", client)
+	}
+	if db.calls != 0 {
+		t.Fatalf("expected no storage lookup for blank client id, got %d", db.calls)
+	}
+}
+
+func TestResolveTrimsClientID(t *testing.T) {
+	want := &sessionmodel.Client{ClientID: "client-1"}
+	db := &resolveClientDB{client: want}
+
+	client, err := Resolve(context.Background(), db, " client-1 ")
+	if err != nil {
+		t.Fatalf("expected client resolution to succeed, got %v", err)
+	}
+	if client != want {
+		t.Fatalf("expected resolved client %#v, got %#v", want, client)
+	}
+	if db.calls != 1 {
+		t.Fatalf("expected one storage lookup, got %d", db.calls)
+	}
+}