Set up default currency accounts automatically (#72)

backend/product/payments/service_test.go

@@ -76,15 +76,25 @@ func (s *memoryStore) Attach(_ context.Context, r *Record, id string) error {
 }
 
 type provider struct {
-	mu        sync.Mutex
-	accepted  int
-	lost      bool
-	status    string
-	key       string
-	namespace string
+	mu           sync.Mutex
+	accepted     int
+	lost         bool
+	status       string
+	key          string
+	namespace    string
+	setupCalls   int
+	setupSubject string
+	setupErr     error
 }
 
 func (p *provider) Namespace() string { return p.namespace }
+func (p *provider) EnsureAccounts(_ context.Context, subject string) error {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	p.setupCalls++
+	p.setupSubject = subject
+	return p.setupErr
+}
 func (p *provider) Accounts(context.Context, string) ([]Account, error) {
 	return []Account{{ID: "ledger", Currency: "EUR", Precision: 2, Available: 5000}}, nil
 }