test: integration tests for NIP-04 Encrypted Direct Messages (Kind 4)

[phoenix-server]

Summary

NIP-04 encrypted direct messages (kind 4) are listed in the relay's supported NIPs but have no integration test coverage. The flow differs from kind 1 in that messages are targeted to a recipient via a p tag, and access control (if any) hinges on that tag.

What to test

• Alice publishes a kind 4 event with Bob's pubkey in a p tag → accepted and stored
• Alice can retrieve her sent DM by event ID
• Bob subscribes with a filter for #p matching his pubkey → receives Alice's DM
• A third party (Charlie) subscribed to Bob's pubkey filter should not receive the encrypted content differently (relay stores and forwards the ciphertext as-is)
• Duplicate kind 4 event submission → returns duplicate: command result

Relevant code

• src/constants/base.ts — EventKinds.ENCRYPTED_DIRECT_MESSAGE
• src/handlers/event-strategies/default-event-strategy.ts

Suggested location

test/integration/features/nip-04/nip-04.feature

[Priyanshubhartistm]

Hi @phoenix-server ,@cameri , Could you please assign this to me ?

[kanishka0411]

Hi! I’d like to work on this :-)
I'm planning to add a nip-04.feature + step definitions file following the same pattern as the existing NIP tests. Will cover all the cases mentioned -send, retrieve by ID, #p filter, Charlie forwarding, and duplicate rejection.