fix(analysis): return explicit error for unknown edge kind in GetEdgeCompositionPath

packages/go/analysis/ad/ad.go

@@ -724,6 +724,8 @@ func GetEdgeCompositionPath(ctx context.Context, db graph.Database, edge *graph.
 			pathSet, err = GetCoerceAndRelayNTLMtoADCSEdgeComposition(ctx, db, edge)
 		case ad.CoerceAndRelayNTLMToSMB:
 			pathSet, err = GetCoerceAndRelayNTLMtoSMBEdgeComposition(ctx, db, edge)
+		default:
+			err = fmt.Errorf("no edge composition handler for kind %s", edge.Kind.String())
 		}
 		return err
 	}); err != nil {

packages/go/analysis/ad/ad_test.go

@@ -0,0 +1,62 @@
+// Copyright 2026 Specter Ops, Inc.
+//
+// Licensed under the Apache License, Version 2.0
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package ad_test
+
+import (
+	"context"
+	"testing"
+
+	ad2 "github.com/specterops/bloodhound/packages/go/analysis/ad"
+	"github.com/specterops/dawgs/graph"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// mockDatabase is a minimal graph.Database implementation used to exercise
+// code paths that do not depend on a real driver-backed transaction.
+type mockDatabase struct{}
+
+var _ graph.Database = mockDatabase{}
+
+func (s mockDatabase) SetWriteFlushSize(int) {}
+func (s mockDatabase) SetBatchWriteSize(int) {}
+func (s mockDatabase) ReadTransaction(_ context.Context, txDelegate graph.TransactionDelegate, _ ...graph.TransactionOption) error {
+	return txDelegate(nil)
+}
+func (s mockDatabase) WriteTransaction(_ context.Context, txDelegate graph.TransactionDelegate, _ ...graph.TransactionOption) error {
+	return txDelegate(nil)
+}
+func (s mockDatabase) BatchOperation(_ context.Context, _ graph.BatchDelegate, _ ...graph.BatchOption) error {
+	return nil
+}
+func (s mockDatabase) AssertSchema(_ context.Context, _ graph.Schema) error    { return nil }
+func (s mockDatabase) SetDefaultGraph(_ context.Context, _ graph.Graph) error  { return nil }
+func (s mockDatabase) Run(_ context.Context, _ string, _ map[string]any) error { return nil }
+func (s mockDatabase) Close(_ context.Context) error                           { return nil }
+func (s mockDatabase) FetchKinds(_ context.Context) (graph.Kinds, error)       { return graph.Kinds{}, nil }
+func (s mockDatabase) RefreshKinds(_ context.Context) error                    { return nil }
+func (s mockDatabase) OptimizeStorage(_ context.Context) error                 { return nil }
+
+func TestGetEdgeCompositionPathUnknownEdgeKind(t *testing.T) {
+	edge := &graph.Relationship{Kind: graph.StringKind("NotARealEdgeKind")}
+
+	pathSet, err := ad2.GetEdgeCompositionPath(context.Background(), mockDatabase{}, edge)
+
+	require.Error(t, err)
+	assert.ErrorContains(t, err, "no edge composition handler for kind NotARealEdgeKind")
+	assert.Equal(t, 0, pathSet.Len())
+}