WIP

test/import-boundaries.mjs

@@ -0,0 +1,40 @@
+// The drop-in guarantee (plan step 1.1): src/chat/ imports nothing from the
+// rest of this service, and nothing there imports it back.
+import { readdirSync, readFileSync, statSync } from 'node:fs';
+import { join, dirname, relative } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const root = join(dirname(fileURLToPath(import.meta.url)), '..');
+const CHAT = join(root, 'src', 'chat');
+const BACK = join(root, 'src', 'runner'), LLM = join(root, 'src', 'llm'), DB = join(root, 'src', 'db.js');
+
+function walk(dir) {
+  return readdirSync(dir).flatMap(f => {
+    const p = join(dir, f);
+    return statSync(p).isDirectory() ? walk(p) : [p];
+  });
+}
+
+let bad = 0;
+for (const f of walk(CHAT)) {
+  const text = readFileSync(f, 'utf8');
+  for (const m of text.matchAll(/from\s+['"](\.[^'"]+)['"]/g)) {
+    const target = new URL(m[1], 'file://' + f).pathname;
+    if (target === DB || target.startsWith(BACK) || target.startsWith(LLM)) {
+      console.error(`FAIL - ${relative(root, f)} imports ${relative(root, target)}`);
+      bad++;
+    }
+  }
+}
+for (const dir of [BACK, LLM]) {
+  for (const f of walk(dir)) {
+    const text = readFileSync(f, 'utf8');
+    if (/from\s+['"]\.\.\/chat/.test(text)) {
+      console.error(`FAIL - ${relative(root, f)} imports the chat back`);
+      bad++;
+    }
+  }
+}
+
+console.log(bad ? `${bad} boundary violations` : 'ok - chat keeps to itself');
+process.exit(bad ? 1 : 0);