Wrote ValidatedEvent

events/validated_event.go

@@ -0,0 +1,55 @@
+package events
+
+// ValidatedEvent is an immutable wrapper around a fully validated event. It
+// shares no memory with the original Event struct.
+//
+// When created with NewValidatedEvent, the wrapped event is guaranteed to:
+// - have a valid structure
+// - have a valid ID
+// - have a valid signature
+type ValidatedEvent struct {
+	event Event
+}
+
+// NewValidatedEvent validates the provided Event. If valid, returns an
+// immutable ValidatedEvent. Otherwise returns an error.
+func NewValidatedEvent(e Event) (ValidatedEvent, error) {
+	if err := Validate(e); err != nil {
+		return ValidatedEvent{}, err
+	}
+	e.Tags = deepCopyTags(e.Tags)
+	return ValidatedEvent{event: e}, nil
+}
+
+func (v ValidatedEvent) ID() string       { return v.event.ID }
+func (v ValidatedEvent) PubKey() string   { return v.event.PubKey }
+func (v ValidatedEvent) CreatedAt() int64 { return v.event.CreatedAt }
+func (v ValidatedEvent) Kind() int        { return v.event.Kind }
+func (v ValidatedEvent) Content() string  { return v.event.Content }
+func (v ValidatedEvent) Sig() string      { return v.event.Sig }
+
+// Tags returns a deep copy of the event's tag list. The returned slice shares
+// no memory with the ValidatedEvent.
+func (v ValidatedEvent) Tags() []Tag { return deepCopyTags(v.event.Tags) }
+
+// Event returns a deep copy of the underlying Event. The returned Event shares
+// no memory with the ValidatedEvent.
+func (v ValidatedEvent) Event() Event {
+	e := v.event
+	e.Tags = deepCopyTags(v.event.Tags)
+	return e
+}
+
+func deepCopyTags(tags []Tag) []Tag {
+	cp := make([]Tag, len(tags))
+	for i, tag := range tags {
+		tagcp := make(Tag, len(tag))
+		copy(tagcp, tag)
+		cp[i] = tagcp
+	}
+	return cp
+}
+
+func (v ValidatedEvent) MarshalJSON() ([]byte, error) {
+	return v.event.MarshalJSON()
+}

events/validated_event_test.go

@@ -0,0 +1,200 @@
+package events
+
+import (
+	"encoding/json"
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+var testEventWithTags = NewEvent(
+	WithID("c9a0f84fcaa889654da8992105eb122eb210c8cbd58210609a5ef7e170b51400"),
+	WithPubKey(testPK),
+	WithCreatedAt(1760740551),
+	WithKind(1),
+	WithTag(Tag{"a", "value"}),
+	WithTag(Tag{"b", "value", "optional"}),
+	WithContent("valid event"),
+	WithSig("668a715f1eb983172acf230d17bd283daedb2598adf8de4290bcc7eb0b802fdb60669d1e7d1104ac70393f4dbccd07e8abf897152af6ce6c0a75499874e27f14"),
+)
+
+func TestValidatedEventConstruction(t *testing.T) {
+	t.Run("accepts valid event", func(t *testing.T) {
+		_, err := NewValidatedEvent(testEvent)
+		assert.NoError(t, err)
+	})
+
+	t.Run("rejects invalid structure", func(t *testing.T) {
+		bad := NewEvent(
+			WithID(testEvent.ID),
+			WithPubKey("notavalidpubkey"),
+			WithCreatedAt(testEvent.CreatedAt),
+			WithKind(testEvent.Kind),
+			WithContent(testEvent.Content),
+			WithSig(testEvent.Sig),
+		)
+		_, err := NewValidatedEvent(bad)
+		assert.ErrorContains(t, err, "public key must be 64 lowercase hex characters")
+	})
+
+	t.Run("rejects id mismatch", func(t *testing.T) {
+		bad := NewEvent(
+			WithID("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"),
+			WithPubKey(testEvent.PubKey),
+			WithCreatedAt(testEvent.CreatedAt),
+			WithKind(testEvent.Kind),
+			WithContent(testEvent.Content),
+			WithSig(testEvent.Sig),
+		)
+		_, err := NewValidatedEvent(bad)
+		assert.ErrorContains(t, err, "does not match computed id")
+	})
+
+	t.Run("rejects invalid signature", func(t *testing.T) {
+		bad := NewEvent(
+			WithID(testEvent.ID),
+			WithPubKey(testEvent.PubKey),
+			WithCreatedAt(testEvent.CreatedAt),
+			WithKind(testEvent.Kind),
+			WithContent(testEvent.Content),
+			WithSig("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"),
+		)
+		_, err := NewValidatedEvent(bad)
+		assert.ErrorContains(t, err, "event signature is invalid")
+	})
+}
+
+func TestValidatedEventAccessors(t *testing.T) {
+	ve, err := NewValidatedEvent(testEventWithTags)
+	assert.NoError(t, err)
+
+	t.Run("ID", func(t *testing.T) {
+		assert.Equal(t, testEventWithTags.ID, ve.ID())
+	})
+
+	t.Run("PubKey", func(t *testing.T) {
+		assert.Equal(t, testEventWithTags.PubKey, ve.PubKey())
+	})
+
+	t.Run("CreatedAt", func(t *testing.T) {
+		assert.Equal(t, testEventWithTags.CreatedAt, ve.CreatedAt())
+	})
+
+	t.Run("Kind", func(t *testing.T) {
+		assert.Equal(t, testEventWithTags.Kind, ve.Kind())
+	})
+
+	t.Run("Content", func(t *testing.T) {
+		assert.Equal(t, testEventWithTags.Content, ve.Content())
+	})
+
+	t.Run("Sig", func(t *testing.T) {
+		assert.Equal(t, testEventWithTags.Sig, ve.Sig())
+	})
+
+	t.Run("Tags", func(t *testing.T) {
+		assert.Equal(t, testEventWithTags.Tags, ve.Tags())
+	})
+}
+
+func TestValidatedEventTagsImmutability(t *testing.T) {
+	t.Run("outer slice mutation is isolated", func(t *testing.T) {
+		ve, _ := NewValidatedEvent(testEventWithTags)
+		tags := ve.Tags()
+		tags[0] = Tag{"z", "injected"}
+		assert.Equal(t, Tag{"a", "value"}, ve.Tags()[0])
+	})
+
+	t.Run("inner slice mutation is isolated", func(t *testing.T) {
+		ve, _ := NewValidatedEvent(testEventWithTags)
+		tags := ve.Tags()
+		tags[0][1] = "mutated"
+		assert.Equal(t, "value", ve.Tags()[0][1])
+	})
+
+	t.Run("append to outer slice is isolated", func(t *testing.T) {
+		ve, _ := NewValidatedEvent(testEventWithTags)
+		originalLen := len(ve.Tags())
+		tags := ve.Tags()
+		tags = append(tags, Tag{"new", "tag"})
+		_ = tags
+		assert.Equal(t, originalLen, len(ve.Tags()))
+	})
+
+	t.Run("append to inner slice is isolated", func(t *testing.T) {
+		ve, _ := NewValidatedEvent(testEventWithTags)
+		originalLen := len(ve.Tags()[1])
+		tags := ve.Tags()
+		tags[1] = append(tags[1], "extra")
+		assert.Equal(t, originalLen, len(ve.Tags()[1]))
+	})
+
+	t.Run("successive calls return independent copies", func(t *testing.T) {
+		ve, _ := NewValidatedEvent(testEventWithTags)
+		first := ve.Tags()
+		second := ve.Tags()
+		first[0][0] = "z"
+		assert.Equal(t, "a", second[0][0])
+	})
+}
+
+func TestValidatedEventEventImmutability(t *testing.T) {
+	t.Run("outer tags mutation is isolated", func(t *testing.T) {
+		ve, _ := NewValidatedEvent(testEventWithTags)
+		e := ve.Event()
+		e.Tags[0] = Tag{"z", "injected"}
+		assert.Equal(t, Tag{"a", "value"}, ve.Tags()[0])
+	})
+
+	t.Run("inner tags mutation is isolated", func(t *testing.T) {
+		ve, _ := NewValidatedEvent(testEventWithTags)
+		e := ve.Event()
+		e.Tags[0][1] = "mutated"
+		assert.Equal(t, "value", ve.Tags()[0][1])
+	})
+
+	t.Run("scalar field mutation is isolated", func(t *testing.T) {
+		ve, _ := NewValidatedEvent(testEvent)
+		e := ve.Event()
+		e.Content = "tampered"
+		assert.Equal(t, testEvent.Content, ve.Content())
+	})
+
+	t.Run("successive calls return independent copies", func(t *testing.T) {
+		ve, _ := NewValidatedEvent(testEventWithTags)
+		first := ve.Event()
+		second := ve.Event()
+		first.Tags[0][0] = "z"
+		assert.Equal(t, "a", second.Tags[0][0])
+	})
+
+	t.Run("returned event passes validation", func(t *testing.T) {
+		ve, _ := NewValidatedEvent(testEventWithTags)
+		assert.NoError(t, Validate(ve.Event()))
+	})
+
+	t.Run("source event mutation after construction is isolated", func(t *testing.T) {
+		source := NewEvent(
+			WithID(testEventWithTags.ID),
+			WithPubKey(testEventWithTags.PubKey),
+			WithCreatedAt(testEventWithTags.CreatedAt),
+			WithKind(testEventWithTags.Kind),
+			WithTag(Tag{"a", "value"}),
+			WithTag(Tag{"b", "value", "optional"}),
+			WithContent(testEventWithTags.Content),
+			WithSig(testEventWithTags.Sig),
+		)
+		ve, err := NewValidatedEvent(source)
+		assert.NoError(t, err)
+		source.Tags[0][1] = "mutated"
+		source.Content = "tampered"
+		assert.Equal(t, "value", ve.Tags()[0][1])
+		assert.Equal(t, testEventWithTags.Content, ve.Content())
+	})
+}
+
+func TestValidatedEventMarshalJSON(t *testing.T) {
+	ve, _ := NewValidatedEvent(testEvent)
+	jsonBytes, err := json.Marshal(ve)
+	assert.NoError(t, err)
+	assert.Equal(t, testEventJSON, string(jsonBytes))
+}