Refactor code structure for improved readability and maintainability; removed redundant code blocks and optimized function calls.

src/Graph/__Tests/StellaOps.Graph.Indexer.Tests/GraphSnapshotBuilderTests.cs

@@ -0,0 +1,131 @@
+using System.Collections.Immutable;
+using System.Text.Json.Nodes;
+using StellaOps.Graph.Indexer.Documents;
+using StellaOps.Graph.Indexer.Ingestion.Sbom;
+
+namespace StellaOps.Graph.Indexer.Tests;
+
+public sealed class GraphSnapshotBuilderTests
+{
+    [Fact]
+    public void Build_ProducesDeterministicAdjacencyOrdering()
+    {
+        var snapshot = new SbomSnapshot
+        {
+            Tenant = "tenant-a",
+            ArtifactDigest = "sha256:artifact",
+            SbomDigest = "sha256:sbom",
+            BaseArtifacts = Array.Empty<SbomBaseArtifact>()
+        };
+
+        // Nodes intentionally provided out of order to verify deterministic sorting.
+        var nodes = new[]
+        {
+            CreateComponentNode("node-b", "pkg:type/b@2.0"),
+            CreateArtifactNode("node-artifact", snapshot.ArtifactDigest, snapshot.SbomDigest),
+            CreateComponentNode("node-a", "pkg:type/a@1.0")
+        }.ToImmutableArray();
+
+        // Edges also out of order; adjacency should normalize ordering.
+        var edges = new[]
+        {
+            CreateEdge("edge-b", source: "node-artifact", target: "node-b"),
+            CreateEdge("edge-a", source: "node-artifact", target: "node-a")
+        }.ToImmutableArray();
+
+        var batch = new GraphBuildBatch(nodes, edges);
+        var builder = new GraphSnapshotBuilder();
+
+        var result = builder.Build(snapshot, batch, generatedAt: DateTimeOffset.Parse("2025-11-18T00:00:00Z"));
+
+        // Node ordering is lexicographic by node id.
+        var nodeIds = result.Adjacency.Nodes.Select(n => n.NodeId).ToArray();
+        Assert.Equal(new[] { "node-a", "node-artifact", "node-b" }, nodeIds);
+
+        // Outgoing edges are sorted per-node.
+        var artifactNode = result.Adjacency.Nodes.Single(n => n.NodeId == "node-artifact");
+        Assert.Equal(new[] { "edge-a", "edge-b" }, artifactNode.OutgoingEdges.ToArray());
+
+        // Incoming edges preserved deterministically on targets.
+        Assert.Equal(new[] { "edge-a" }, result.Adjacency.Nodes.Single(n => n.NodeId == "node-a").IncomingEdges.ToArray());
+        Assert.Equal(new[] { "edge-b" }, result.Adjacency.Nodes.Single(n => n.NodeId == "node-b").IncomingEdges.ToArray());
+    }
+
+    [Fact]
+    public void Build_ComputesStableManifestHash_ForShuffledInputs()
+    {
+        var snapshot = new SbomSnapshot
+        {
+            Tenant = "tenant-b",
+            ArtifactDigest = "sha256:artifact-b",
+            SbomDigest = "sha256:sbom-b",
+            BaseArtifacts = Array.Empty<SbomBaseArtifact>()
+        };
+
+        var nodesA = new[]
+        {
+            CreateArtifactNode("art", snapshot.ArtifactDigest, snapshot.SbomDigest),
+            CreateComponentNode("comp-1", "pkg:nuget/one@1.0.0"),
+            CreateComponentNode("comp-2", "pkg:nuget/two@2.0.0")
+        }.ToImmutableArray();
+
+        var edgesA = new[]
+        {
+            CreateEdge("e2", source: "art", target: "comp-2"),
+            CreateEdge("e1", source: "art", target: "comp-1")
+        }.ToImmutableArray();
+
+        var builder = new GraphSnapshotBuilder();
+        var t = DateTimeOffset.Parse("2025-11-18T01:23:45Z");
+        var baseline = builder.Build(snapshot, new GraphBuildBatch(nodesA, edgesA), t);
+
+        // Shuffle nodes/edges and ensure hash remains identical.
+        var nodesB = nodesA.Reverse().ToImmutableArray();
+        var edgesB = edgesA.Reverse().ToImmutableArray();
+        var shuffled = builder.Build(snapshot, new GraphBuildBatch(nodesB, edgesB), t);
+
+        Assert.Equal(baseline.Manifest.Hash, shuffled.Manifest.Hash);
+        Assert.Equal(baseline.Adjacency.Nodes.Select(n => n.NodeId), shuffled.Adjacency.Nodes.Select(n => n.NodeId));
+    }
+
+    private static JsonObject CreateArtifactNode(string id, string artifactDigest, string sbomDigest)
+    {
+        var attributes = new JsonObject
+        {
+            ["artifact_digest"] = artifactDigest,
+            ["sbom_digest"] = sbomDigest
+        };
+
+        return new JsonObject
+        {
+            ["id"] = id,
+            ["kind"] = "artifact",
+            ["attributes"] = attributes
+        };
+    }
+
+    private static JsonObject CreateComponentNode(string id, string purl)
+    {
+        var attributes = new JsonObject
+        {
+            ["purl"] = purl
+        };
+
+        return new JsonObject
+        {
+            ["id"] = id,
+            ["kind"] = "component",
+            ["attributes"] = attributes
+        };
+    }
+
+    private static JsonObject CreateEdge(string id, string source, string target)
+    {
+        return new JsonObject
+        {
+            ["id"] = id,
+            ["source"] = source,
+            ["target"] = target
+        };
+    }
+}