Initial JS runtime and Arborix Implementation

ext/js/src/manifest.js

@@ -0,0 +1,167 @@
+/**
+ * manifest.js — Minimal manifest parsing and export lookup.
+ *
+ * The manifest is a JSON object with fields:
+ *   schema, bundleType, tree, runtime, closure, roots, exports,
+ *   imports, sections, metadata
+ *
+ * We parse only what we need for runtime entrypoint selection.
+ */
+
+/**
+ * Validate the manifest against the runtime profile requirements.
+ * Throws on violation.
+ */
+export function validateManifest(manifest) {
+  if (manifest.schema !== "arborix.bundle.manifest.v1") {
+    throw new Error(
+      `unsupported manifest schema: ${manifest.schema}`
+    );
+  }
+  if (manifest.bundleType !== "tree-calculus-executable-object") {
+    throw new Error(
+      `unsupported bundle type: ${manifest.bundleType}`
+    );
+  }
+
+  const tree = manifest.tree;
+  if (tree.calculus !== "tree-calculus.v1") {
+    throw new Error(`unsupported calculus: ${tree.calculus}`);
+  }
+  if (tree.nodeHash.algorithm !== "sha256") {
+    throw new Error(
+      `unsupported node hash algorithm: ${tree.nodeHash.algorithm}`
+    );
+  }
+  if (tree.nodeHash.domain !== "tricu.merkle.node.v1" && tree.nodeHash.domain !== "arborix.merkle.node.v1") {
+    throw new Error(
+      `unsupported node hash domain: ${tree.nodeHash.domain}`
+    );
+  }
+  if (tree.nodePayload !== "arborix.merkle.payload.v1") {
+    throw new Error(`unsupported node payload: ${tree.nodePayload}`);
+  }
+
+  const runtime = manifest.runtime;
+  if (runtime.semantics !== "tree-calculus.v1") {
+    throw new Error(`unsupported runtime semantics: ${runtime.semantics}`);
+  }
+  if (runtime.abi !== "arborix.abi.tree.v1") {
+    throw new Error(`unsupported runtime ABI: ${runtime.abi}`);
+  }
+  if (runtime.capabilities && runtime.capabilities.length > 0) {
+    throw new Error(
+      `host/runtime capabilities not supported: ${runtime.capabilities.join(", ")}`
+    );
+  }
+
+  if (manifest.closure !== "complete") {
+    throw new Error("bundle v1 requires closure = complete");
+  }
+  if (manifest.imports && manifest.imports.length > 0) {
+    throw new Error("bundle v1 requires an empty imports list");
+  }
+  if (!manifest.roots || manifest.roots.length === 0) {
+    throw new Error("manifest has no roots");
+  }
+  if (!manifest.exports || manifest.exports.length === 0) {
+    throw new Error("manifest has no exports");
+  }
+
+  for (const exp of manifest.exports) {
+    if (!exp.name) {
+      throw new Error("manifest export has empty name");
+    }
+    if (!exp.root) {
+      throw new Error("manifest export has empty root");
+    }
+  }
+}
+
+/**
+ * Select an export hash given a requested name.
+ *
+ * Selection strategy:
+ *   1. Explicit export name
+ *   2. Export named "main"
+ *   3. Single export (auto-select)
+ *   4. Error if multiple exports and no "main"
+ */
+export function selectExport(manifest, requestedName) {
+  const exports = manifest.exports || [];
+
+  // Strategy 1: explicit name
+  if (requestedName) {
+    const found = exports.find((e) => e.name === requestedName);
+    if (found) {
+      return found;
+    }
+    throw new Error(
+      `requested export "${requestedName}" not found. Available: ${exports.map((e) => e.name).join(", ")}`
+    );
+  }
+
+  // Strategy 2: prefer "main"
+  const mainExport = exports.find((e) => e.name === "main");
+  if (mainExport) {
+    return mainExport;
+  }
+
+  // Strategy 3: single export
+  if (exports.length === 1) {
+    return exports[0];
+  }
+
+  // Strategy 4: multiple exports, require explicit
+  throw new Error(
+    `multiple exports available but none named "main": ${exports.map((e) => e.name).join(", ")}. Specify an export name.`
+  );
+}
+
+/**
+ * Get all root hashes from the manifest.
+ */
+export function getRootHashes(manifest) {
+  return (manifest.roots || []).map((r) => r.hash);
+}
+
+/**
+ * Get all export names.
+ */
+export function getExportNames(manifest) {
+  return (manifest.exports || []).map((e) => e.name);
+}
+
+/**
+ * Print manifest summary info.
+ */
+export function printManifestInfo(manifest, indent = "") {
+  const tree = manifest.tree;
+  const runtime = manifest.runtime;
+
+  console.log(`${indent}Schema:          ${manifest.schema}`);
+  console.log(`${indent}Bundle type:     ${manifest.bundleType}`);
+  console.log(`${indent}Closure:         ${manifest.closure}`);
+  console.log(`${indent}Tree calculus:   ${tree.calculus}`);
+  console.log(`${indent}Hash algo:       ${tree.nodeHash.algorithm}`);
+  console.log(`${indent}Hash domain:     ${tree.nodeHash.domain}`);
+  console.log(`${indent}Runtime:         ${runtime.semantics}`);
+  console.log(`${indent}ABI:             ${runtime.abi}`);
+  console.log(`${indent}Evaluation:      ${runtime.evaluation || "N/A"}`);
+  console.log("");
+  console.log(`${indent}Roots (${getRootHashes(manifest).length}):`);
+  for (const root of getRootHashes(manifest)) {
+    console.log(`${indent}  ${root.substring(0, 16)}...`);
+  }
+  console.log("");
+  console.log(`${indent}Exports (${getExportNames(manifest).length}):`);
+  for (const name of getExportNames(manifest)) {
+    console.log(`${indent}  ${name}`);
+  }
+
+  const meta = manifest.metadata;
+  if (meta && meta.createdBy) {
+    console.log("");
+    console.log(`${indent}Created by:      ${meta.createdBy}`);
+  }
+}