Testing with MockProvider

MockProvider is an in-memory Provider in the core module — no network calls, no credentials, safe for concurrent use.

mock := gosms.NewMockProvider()
client := gosms.NewClient(mock)

result, err := client.Send(ctx, "+15551234567", "Test message")

if mock.MessageCount() != 1 {
    t.Error("Expected 1 message")
}

lastMsg := mock.LastMessage()
if lastMsg.Message.Body != "Test message" {
    t.Error("Message body mismatch")
}

Injecting failures

// Every Send returns StatusFailed.
mock.WithFailAll(true)
result, err = client.Send(ctx, "+15551234567", "This will fail")

// Every Send returns this error instead of succeeding.
mock.WithSendError(gosms.ErrRateLimited)
_, err = client.Send(ctx, "+15551234567", "This will error")
// errors.Is(err, gosms.ErrRateLimited) == true

// GetStatus returns this error instead of a status.
mock.WithStatusError(gosms.ErrProviderError)

// Simulate network latency (respects context cancellation).
mock.WithLatency(50 * time.Millisecond)

// Whether accepted messages should also resolve to StatusDelivered on
// GetStatus (default true).
mock.WithDeliverAll(false)

Inspecting sent messages

Method	Returns
Messages()	All sent *MockMessages, in order
LastMessage()	The most recent *MockMessage, or nil if none sent
MessageCount()	Number of messages sent
FindMessagesByTo(to)	All messages sent to a given recipient
FindMessageByID(id)	The message with the given provider message ID, or nil
SetStatus(id, status)	Manually set the status returned by GetStatus for a message ID

MockMessage carries MessageID, Message (the original *gosms.Message), SentAt, and Status.

Resetting between tests

mock.Clear()  // clears sent messages and statuses only
mock.Reset()  // clears everything, including injected failures/latency

Prefer Reset() in t.Cleanup when a test configures failure injection, so state never leaks into the next test.