Add typed self-state operation service

scripts/void-self-state.mjs

@@ -0,0 +1,78 @@
+import { existsSync, readFileSync } from "node:fs";
+import { createRequire } from "node:module";
+import { dirname, resolve } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const repoRoot = resolve(dirname(fileURLToPath(import.meta.url)), "..");
+const require = createRequire(import.meta.url);
+const coreDistPath = resolve(repoRoot, "packages/core/dist/index.js");
+
+if (!existsSync(coreDistPath)) {
+  throw new Error(`Missing built core package at ${coreDistPath}. Run npm run build first.`);
+}
+
+const { applyVoidSelfStateOperation } = require(coreDistPath);
+
+async function main() {
+  const [command, ...rest] = process.argv.slice(2);
+  const args = parseArgs(rest);
+
+  if (command !== "apply-operation") {
+    throw new Error("Expected command: apply-operation.");
+  }
+
+  const canonicalPath = requirePathArg(args, "canonical");
+  const operation = readOperation(args);
+  const result = await applyVoidSelfStateOperation({ canonicalPath }, operation);
+  process.stdout.write(`${JSON.stringify(result)}\n`);
+}
+
+function readOperation(args) {
+  if (typeof args.operation === "string" && args.operation.trim().length > 0) {
+    return JSON.parse(args.operation);
+  }
+
+  if (typeof args["operation-file"] === "string" && args["operation-file"].trim().length > 0) {
+    return JSON.parse(stripLeadingBom(readFileSync(resolve(args["operation-file"]), "utf8")));
+  }
+
+  throw new Error("apply-operation requires --operation JSON or --operation-file path.");
+}
+
+function parseArgs(argv) {
+  const args = {};
+
+  for (let index = 0; index < argv.length; index += 1) {
+    const token = argv[index];
+    if (!token.startsWith("--")) {
+      continue;
+    }
+
+    const key = token.slice(2);
+    const next = argv[index + 1];
+    if (!next || next.startsWith("--")) {
+      args[key] = "true";
+      continue;
+    }
+
+    args[key] = next;
+    index += 1;
+  }
+
+  return args;
+}
+
+function requirePathArg(args, key) {
+  const value = args[key];
+  if (typeof value !== "string" || value.trim().length === 0) {
+    throw new Error(`Missing required --${key} path.`);
+  }
+
+  return resolve(value);
+}
+
+function stripLeadingBom(input) {
+  return input.charCodeAt(0) === 0xfeff ? input.slice(1) : input;
+}
+
+await main();