Extract event signing into its own class

spec/nostr/crypto_spec.rb

@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Nostr::Crypto do
+  let(:crypto) { described_class.new }
+
+  describe '#sign_event' do
+    let(:keypair) do
+      Nostr::KeyPair.new(
+        public_key: '8a9d69c56e3c691bec8f9565e4dcbe38ae1d88fffeec3ce66b9f47558a3aa8ca',
+        private_key: '3185a47e3802f956ca5a2b4ea606c1d51c7610f239617e8f0f218d55bdf2b757'
+      )
+    end
+
+    let(:event) do
+      Nostr::Event.new(
+        kind: Nostr::EventKind::TEXT_NOTE,
+        content: 'Your feedback is appreciated, now pay $8',
+        pubkey: keypair.public_key
+      )
+    end
+
+    it 'signs an event' do
+      signed_event = crypto.sign_event(event, keypair.private_key)
+
+      aggregate_failures do
+        expect(signed_event.id.length).to eq(64)
+        expect(signed_event.sig.length).to eq(128)
+      end
+    end
+  end
+end

spec/nostr/event_spec.rb

@@ -121,6 +121,15 @@ RSpec.describe Nostr::Event do
     end
   end
 
+  describe '#id=' do
+    it 'sets the event id' do
+      new_id = '20f31a9b2a0ced48a167add9732ccade1dca5e34b44316e37da4af33bc8946a9'
+
+      event.id = new_id
+      expect(event.id).to eq(new_id)
+    end
+  end
+
   describe '#pubkey' do
     it 'exposes the event pubkey' do
       expect(event.pubkey).to eq('ccf9fdf3e1466d7c20969c71ec98defcf5f54aee088513e1b73ccb7bd770d460')
@@ -156,6 +165,41 @@ RSpec.describe Nostr::Event do
     end
   end
 
+  describe '#sig=' do
+    it 'sets the event signature' do
+      new_signature = '058613f8d34c053294cc28b7f9e1f8f0e80fd1ac94fb20f2da6ca514e7360b39' \
+                      '63d0086171f842ffebf1f7790ce147b4811a15ef3f59c76ec1324b970cc57ffe'
+
+      event.sig = new_signature
+      expect(event.sig).to eq(new_signature)
+    end
+  end
+
+  describe '#sign' do
+    let(:event) do
+      described_class.new(
+        pubkey: 'ccf9fdf3e1466d7c20969c71ec98defcf5f54aee088513e1b73ccb7bd770d460',
+        kind: Nostr::EventKind::TEXT_NOTE,
+        content: 'Your feedback is appreciated, now pay $8'
+      )
+    end
+    let(:keypair) do
+      Nostr::KeyPair.new(
+        public_key: '8a9d69c56e3c691bec8f9565e4dcbe38ae1d88fffeec3ce66b9f47558a3aa8ca',
+        private_key: '3185a47e3802f956ca5a2b4ea606c1d51c7610f239617e8f0f218d55bdf2b757'
+      )
+    end
+
+    it 'signs the event' do
+      event.sign(keypair.private_key)
+
+      aggregate_failures do
+        expect(event.id.length).to eq(64)
+        expect(event.sig.length).to eq(128)
+      end
+    end
+  end
+
   describe '#tags' do
     it 'exposes the event tags' do
       expect(event.tags).to eq(