In this commit, we move to start rejecting any normal payments that
aren't keysend, if they don't also include the MPP invoice payload. With
this change, we require that some sort of e2e secret (either the payment
addr or the keysend pre-image) is present in a payload before we'll
accept the payment.
The second portion of the commit also updates all current tests in the
package. We kept the base `TestSettleInvoice` test in-tact as it still
exercises some useful behavior. However, we've removed all cases that
allow an overpayment, as the new MPP logic doesn't allow overpayment for
various reasons. In addition to this, some of the returned errors are
slightly different, tho the actual behavior is equivalent.
Previously it wasn't possible to store a preimage in the invoice
database and signal that a payment should not be settled right away. The
only way to hold a payment was to insert the magic UnknownPreimage value
in the invoice database. This commit introduces a distinct flag to
signal that an invoice is a hold invoice and thereby allows the preimage
to be present in the database already.
Preparation for (key send) hodl invoices for which we already know the
preimage.
This commit adds handling code for the key send custom record. If this
record is present and its hash matches the payment hash, invoice
registry will insert a new invoice into the database "just in time". The
subsequent settle flow is unchanged. The newly inserted invoice is
picked up and settled. Notifications will be broadcast as usual.
This commit adds InvoiceExpryWatcher which is a separate class that
receives new invoices (and existing ones upon restart) from InvoiceRegistry
and actively watches their expiry. When an invoice is expired
InvoiceExpiryWatcher will call into InvoiceRegistry to cancel the
invoice and by that notify all subscribers about the state change.
This commit adds Clock and DefaultClock and moves the private
invoices.testClock under the clock package while adding basic
unit tests for it.
Clock is an interface currently encapsulating Now() and TickAfter().
It can be added as an external dependency to any class. This way
tests can stub out time.Now() or time.After().
The DefaultClock class simply returns the real time.Now() and
time.After().
