Crussell/backend/testutils/square_stub.go

//go:build test

package testutils

import (
	"context"
	"crypto/sha256"
	"fmt"
	"sync"
	"time"

	"crussell/clock"
	"crussell/internal/square"
)

// NewTestSquareClient returns an in-memory SquareClient for tests that must
// compile under BOTH the dev ("test,dev") and prod ("test,!dev") build tags.
// The real dev mock (internal/square.NewDevClient) is only compiled under the
// dev tag, so prod-tag tests cannot reference it. This lightweight stand-in
// implements just the surface the GDPR erasure / cache-invalidation tests
// exercise (CreateCustomer, CreateCardOnFile, DeleteCustomer,
// DeleteCardOnFile); any other method panics (never called by those tests).
//
// CreateCustomer is deterministic per email: re-provisioning the SAME email
// returns the same id, while a different email (e.g. the anonymized
// anon-{id}@anon.invalid address) mints a different id — the property the
// cache-invalidation tests assert on.
func NewTestSquareClient() square.SquareClient {
	return &testSquareClient{
		customersByEmail: map[string]*square.CustomerResult{},
	}
}

// testSquareClient is a minimal in-memory SquareClient for test-only use.
// It embeds the square.SquareClient interface so it satisfies the full
// interface without implementing every method; only the methods below are
// overridden and actually called by the erasure/cache tests.
type testSquareClient struct {
	square.SquareClient // embedded interface — satisfies SquareClient; unoverridden methods panic if called

	mu               sync.Mutex
	seq              int
	customersByEmail map[string]*square.CustomerResult
}

func (c *testSquareClient) CreateCustomer(ctx context.Context, name, email string) (*square.CustomerResult, error) {
	c.mu.Lock()
	defer c.mu.Unlock()
	if existing, ok := c.customersByEmail[email]; ok {
		return existing, nil
	}
	sum := sha256.Sum256([]byte(email))
	customer := &square.CustomerResult{
		ID:        "cus_test_" + fmt.Sprintf("%x", sum)[:12],
		Email:     email,
		CreatedAt: clock.Now().UTC().Format(time.RFC3339),
	}
	c.customersByEmail[email] = customer
	return customer, nil
}

func (c *testSquareClient) CreateCardOnFile(ctx context.Context, userID, cardToken, customerID string) (*square.CardOnFile, error) {
	c.mu.Lock()
	defer c.mu.Unlock()
	c.seq++
	return &square.CardOnFile{
		ID:         fmt.Sprintf("test_card_%d", c.seq),
		CardID:     fmt.Sprintf("ccof:test_%d", c.seq),
		Brand:      "VISA",
		Last4:      "4242",
		ExpMonth:   12,
		ExpYear:    2030,
		ReferenceID: userID,
		Enabled:    true,
	}, nil
}

func (c *testSquareClient) DeleteCardOnFile(ctx context.Context, cardID string) error {
	return nil
}

func (c *testSquareClient) DeleteCustomer(ctx context.Context, customerID string) error {
	c.mu.Lock()
	defer c.mu.Unlock()
	for email, customer := range c.customersByEmail {
		if customer.ID == customerID {
			delete(c.customersByEmail, email)
			return nil
		}
	}
	return nil
}