Initial JS runtime and Arborix Implementation

ext/js/test/merkle.test.js

@@ -0,0 +1,148 @@
+import { readFileSync } from "node:fs";
+import { strictEqual, ok } from "node:assert";
+import { describe, it } from "node:test";
+import { parseNodeSection } from "../src/bundle.js";
+import {
+  verifyNodeHashes,
+  verifyClosure,
+  verifyRootClosure,
+  deserializePayload,
+  computeNodeHash,
+} from "../src/merkle.js";
+
+describe("merkle — deserializePayload", () => {
+  it("Leaf (0x00)", () => {
+    const result = deserializePayload(Buffer.from([0x00]));
+    strictEqual(result.type, "leaf");
+  });
+
+  it("Stem (0x01 + 32 bytes)", () => {
+    const childHash = Buffer.alloc(32, 0xab);
+    const payload = Buffer.concat([Buffer.from([0x01]), childHash]);
+    const result = deserializePayload(payload);
+    strictEqual(result.type, "stem");
+    strictEqual(result.childHash, "ab".repeat(32));
+  });
+
+  it("Fork (0x02 + 64 bytes)", () => {
+    const left = Buffer.alloc(32, 0x01);
+    const right = Buffer.alloc(32, 0x02);
+    const payload = Buffer.concat([Buffer.from([0x02]), left, right]);
+    const result = deserializePayload(payload);
+    strictEqual(result.type, "fork");
+    strictEqual(result.leftHash, "01".repeat(32));
+    strictEqual(result.rightHash, "02".repeat(32));
+  });
+
+  it("Leaf with extra bytes fails", () => {
+    throws(() => deserializePayload(Buffer.from([0x00, 0x00])), /invalid leaf/);
+  });
+
+  it("Unknown type fails", () => {
+    throws(() => deserializePayload(Buffer.from([0xff])), /unknown type/);
+  });
+});
+
+describe("merkle — computeNodeHash", () => {
+  it("Leaf hash is correct length", () => {
+    const leaf = { type: "leaf" };
+    const hash = computeNodeHash(leaf);
+    strictEqual(hash.length, 64);
+  });
+});
+
+describe("merkle — node section parsing", () => {
+  const fixtureDir = "test/fixtures";
+
+  it("parses id.tri.bundle with correct node count", () => {
+    const data = parseNodeSection(
+      readFileSync(`${fixtureDir}/id.tri.bundle`)
+    );
+    const { nodeMap } = parseNodes(data);
+    strictEqual(nodeMap.size, 4);
+  });
+
+  it("parses true.tri.bundle with correct node count", () => {
+    const data = parseNodeSection(
+      readFileSync(`${fixtureDir}/true.tri.bundle`)
+    );
+    const { nodeMap } = parseNodes(data);
+    strictEqual(nodeMap.size, 2);
+  });
+});
+
+describe("merkle — hash verification", () => {
+  const fixtureDir = "test/fixtures";
+
+  it("id.tri.bundle nodes all verify", () => {
+    const data = parseNodeSection(
+      readFileSync(`${fixtureDir}/id.tri.bundle`)
+    );
+    const { nodeMap } = parseNodes(data);
+    const { verified, mismatches } = verifyNodeHashes(nodeMap);
+    ok(verified, "id.tri.bundle node hashes should verify");
+    strictEqual(mismatches.length, 0);
+  });
+
+  it("corrupted node payload fails hash verification", () => {
+    const data = parseNodeSection(
+      readFileSync(`${fixtureDir}/id.tri.bundle`)
+    );
+    const { nodeMap } = parseNodes(data);
+    // Find a stem node to corrupt
+    let stemKey = null;
+    for (const [key, node] of nodeMap) {
+      if (node.type === "stem") { stemKey = key; break; }
+    }
+    ok(stemKey, "should find a stem node to corrupt");
+    const stem = nodeMap.get(stemKey);
+    // Corrupt the child hash so serializeNode produces a different payload
+    const corrupted = {
+      ...stem,
+      childHash: "00".repeat(32),
+      payload: Buffer.concat([Buffer.from([0x01]), Buffer.alloc(32, 0x00)]),
+    };
+    nodeMap.set(stemKey, corrupted);
+    const { verified, mismatches } = verifyNodeHashes(nodeMap);
+    ok(!verified, "corrupted stem should fail hash verification");
+    ok(mismatches.length > 0, "should have mismatches");
+  });
+});
+
+describe("merkle — closure verification", () => {
+  const fixtureDir = "test/fixtures";
+
+  it("id.tri.bundle has complete closure", () => {
+    const data = parseNodeSection(
+      readFileSync(`${fixtureDir}/id.tri.bundle`)
+    );
+    const { nodeMap } = parseNodes(data);
+    const { complete, missing } = verifyClosure(nodeMap);
+    ok(complete, "id.tri.bundle should have complete closure");
+    strictEqual(missing.length, 0);
+  });
+
+  it("verifyRootClosure checks transitive reachability", () => {
+    const data = parseNodeSection(
+      readFileSync(`${fixtureDir}/id.tri.bundle`)
+    );
+    const { nodeMap } = parseNodes(data);
+    const rootHash = "039cc9aacf5be78ec1975713e6ad154a36988e3f3df18589b0d0c801d0825d78";
+    const { complete, missingRoots } = verifyRootClosure(nodeMap, rootHash);
+    ok(complete, "root should be reachable");
+    strictEqual(missingRoots.length, 0);
+  });
+});
+
+// Helper import
+import { parseNodeSection as parseNodes } from "../src/merkle.js";
+
+// Helper for throws
+function throws(fn, expected) {
+  try {
+    fn();
+    return false;
+  } catch (e) {
+    return expected.test(e.message);
+  }
+}