fix(scripts): guard core test tsgo in sparse worktrees

scripts/lib/tsgo-sparse-guard.mjs

@@ -0,0 +1,88 @@
+import { spawnSync } from "node:child_process";
+import fs from "node:fs";
+import path from "node:path";
+
+const CORE_TEST_CONFIGS = new Set([
+  "tsconfig.core.test.json",
+  "tsconfig.core.test.agents.json",
+  "tsconfig.core.test.non-agents.json",
+]);
+
+const CORE_TEST_REQUIRED_PATHS = [
+  "packages/plugin-package-contract/src/index.ts",
+  "ui/src/i18n/lib/registry.ts",
+  "ui/src/i18n/lib/types.ts",
+  "ui/src/ui/app-settings.ts",
+  "ui/src/ui/gateway.ts",
+];
+
+export function getSparseTsgoGuardError(
+  args,
+  { cwd = process.cwd(), fileExists = fs.existsSync, isSparseCheckoutEnabled } = {},
+) {
+  const projectPath = readProjectFlag(args);
+  if (
+    !projectPath ||
+    !CORE_TEST_CONFIGS.has(path.basename(projectPath)) ||
+    isMetadataOnlyCommand(args)
+  ) {
+    return null;
+  }
+
+  const sparseEnabled =
+    isSparseCheckoutEnabled?.({ cwd }) ?? getGitBooleanConfig("core.sparseCheckout", { cwd });
+  if (!sparseEnabled) {
+    return null;
+  }
+
+  const missingPaths = CORE_TEST_REQUIRED_PATHS.filter(
+    (relativePath) => !fileExists(path.join(cwd, relativePath)),
+  );
+  if (missingPaths.length === 0) {
+    return null;
+  }
+
+  return [
+    `${path.basename(projectPath)} requires a full worktree, but this checkout is sparse and missing files that the core test graph imports:`,
+    ...missingPaths.map((relativePath) => `- ${relativePath}`),
+    'Run "gwt sparse full" in this worktree, then rerun the tsgo command.',
+  ].join("\n");
+}
+
+function getGitBooleanConfig(name, { cwd }) {
+  const result = spawnSync("git", ["config", "--get", "--bool", name], {
+    cwd,
+    encoding: "utf8",
+    stdio: ["ignore", "pipe", "pipe"],
+    shell: process.platform === "win32",
+  });
+
+  if (result.error || (result.status ?? 1) !== 0) {
+    return false;
+  }
+
+  return (result.stdout ?? "").trim() === "true";
+}
+
+function readProjectFlag(args) {
+  return readFlagValue(args, "-p") ?? readFlagValue(args, "--project");
+}
+
+function isMetadataOnlyCommand(args) {
+  return args.some((arg) =>
+    ["--help", "-h", "--version", "-v", "--init", "--showConfig"].includes(arg),
+  );
+}
+
+function readFlagValue(args, name) {
+  for (let index = 0; index < args.length; index++) {
+    const arg = args[index];
+    if (arg === name) {
+      return args[index + 1];
+    }
+    if (arg.startsWith(`${name}=`)) {
+      return arg.slice(name.length + 1);
+    }
+  }
+  return undefined;
+}