feat: add module contracts and discovery

core/src/cli/validate-modules.ts

@@ -0,0 +1,51 @@
+import { readFile } from "node:fs/promises";
+import path from "node:path";
+import { discoverModules, ModuleDiscoveryError } from "../modules/index.js";
+
+interface PackageVersion {
+  version?: unknown;
+}
+
+async function readPackageVersion(packagePath: string): Promise<string> {
+  const packageData = JSON.parse(await readFile(packagePath, "utf8")) as PackageVersion;
+  if (typeof packageData.version !== "string") {
+    throw new Error(`${packagePath} does not declare a version.`);
+  }
+  return packageData.version;
+}
+
+async function main(): Promise<void> {
+  const repositoryRoot = process.cwd();
+  const [platformVersion, moduleSdkVersion] = await Promise.all([
+    readPackageVersion(path.join(repositoryRoot, "package.json")),
+    readPackageVersion(path.join(repositoryRoot, "packages/module-sdk/package.json")),
+  ]);
+  const modules = await discoverModules({
+    moduleSdkVersion,
+    modulesDirectory: path.join(repositoryRoot, "modules"),
+    platformVersion,
+  });
+
+  if (modules.length === 0) {
+    console.log("Module validation passed (0 modules installed).");
+    return;
+  }
+
+  console.log(`Module validation passed (${modules.length} modules):`);
+  for (const discoveredModule of modules) {
+    console.log(`- ${discoveredModule.manifest.id}@${discoveredModule.manifest.version}`);
+  }
+}
+
+main().catch((error: unknown) => {
+  if (error instanceof ModuleDiscoveryError) {
+    console.error(error.message);
+    for (const issue of error.issues) {
+      const issuePath = issue.path ? ` (${issue.path})` : "";
+      console.error(`[${issue.code}] ${issue.moduleDirectory}${issuePath}: ${issue.message}`);
+    }
+  } else {
+    console.error(error instanceof Error ? error.message : String(error));
+  }
+  process.exitCode = 1;
+});