Checkpoint: current Lumen state

pipeline/canonical-json.ts

@@ -0,0 +1,42 @@
+/**
+ * Deterministic JSON serialization — sorted keys recursively, no whitespace.
+ * Required for manifest SHA-256 over exact bytes (SPIKE-04, ARCH 10.5).
+ * Trace: SPIKE-04 §2 manifest, IMPLEMENTATION-CONTRACT.md §15
+ */
+
+export function canonicalJson(value: unknown): string {
+  return stringify(value);
+}
+
+function stringify(value: unknown): string {
+  if (value === null) return "null";
+  if (value === undefined) return "null";
+  const t = typeof value;
+  if (t === "string") return JSON.stringify(value);
+  if (t === "number") {
+    if (!Number.isFinite(value as number)) throw new Error("non-finite number in canonical JSON");
+    return JSON.stringify(value);
+  }
+  if (t === "boolean") return value ? "true" : "false";
+  if (Array.isArray(value)) {
+    const items = (value as unknown[]).map((v) => stringify(v));
+    return `[${items.join(",")}]`;
+  }
+  if (t === "object") {
+    const obj = value as Record<string, unknown>;
+    const keys = Object.keys(obj).sort();
+    const parts: string[] = [];
+    for (const k of keys) {
+      const v = obj[k];
+      if (v === undefined) continue; // omit undefined like JSON.stringify
+      parts.push(`${JSON.stringify(k)}:${stringify(v)}`);
+    }
+    return `{${parts.join(",")}}`;
+  }
+  throw new Error(`unsupported canonical json type ${t}`);
+}
+
+export function canonicalBytes(value: unknown): Uint8Array {
+  const str = canonicalJson(value);
+  return new TextEncoder().encode(str);
+}