fix: block invalid config startup

Co-authored-by: Muhammed Mukhthar CM <mukhtharcm@gmail.com>

src/config/config.backup-rotation.test.ts

@@ -0,0 +1,36 @@
+import fs from "node:fs/promises";
+
+import { describe, expect, it } from "vitest";
+
+import { withTempHome } from "./test-helpers.js";
+import type { ClawdbotConfig } from "./types.js";
+
+describe("config backup rotation", () => {
+  it("keeps a 5-deep backup ring for config writes", async () => {
+    await withTempHome(async () => {
+      const { resolveConfigPath, writeConfigFile } = await import("./config.js");
+      const configPath = resolveConfigPath();
+      const buildConfig = (version: number): ClawdbotConfig =>
+        ({
+          identity: { name: `v${version}` },
+        }) as ClawdbotConfig;
+
+      for (let version = 0; version <= 6; version += 1) {
+        await writeConfigFile(buildConfig(version));
+      }
+
+      const readName = async (suffix = "") => {
+        const raw = await fs.readFile(`${configPath}${suffix}`, "utf-8");
+        return (JSON.parse(raw) as { identity?: { name?: string } }).identity?.name ?? null;
+      };
+
+      await expect(readName()).resolves.toBe("v6");
+      await expect(readName(".bak")).resolves.toBe("v5");
+      await expect(readName(".bak.1")).resolves.toBe("v4");
+      await expect(readName(".bak.2")).resolves.toBe("v3");
+      await expect(readName(".bak.3")).resolves.toBe("v2");
+      await expect(readName(".bak.4")).resolves.toBe("v1");
+      await expect(fs.stat(`${configPath}.bak.5`)).rejects.toThrow();
+    });
+  });
+});

src/config/io.ts

@@ -52,6 +52,8 @@ const SHELL_ENV_EXPECTED_KEYS = [
   "CLAWDBOT_GATEWAY_PASSWORD",
 ];
 
+const CONFIG_BACKUP_COUNT = 5;
+
 export type ParseConfigJson5Result = { ok: true; parsed: unknown } | { ok: false; error: string };
 
 function hashConfigRaw(raw: string | null): string {
@@ -73,6 +75,53 @@ export function resolveConfigSnapshotHash(snapshot: {
   return hashConfigRaw(snapshot.raw);
 }
 
+function coerceConfig(value: unknown): ClawdbotConfig {
+  if (!value || typeof value !== "object" || Array.isArray(value)) {
+    return {};
+  }
+  return value as ClawdbotConfig;
+}
+
+function rotateConfigBackupsSync(configPath: string, ioFs: typeof fs): void {
+  if (CONFIG_BACKUP_COUNT <= 1) return;
+  const backupBase = `${configPath}.bak`;
+  const maxIndex = CONFIG_BACKUP_COUNT - 1;
+  try {
+    ioFs.unlinkSync(`${backupBase}.${maxIndex}`);
+  } catch {
+    // best-effort
+  }
+  for (let index = maxIndex - 1; index >= 1; index -= 1) {
+    try {
+      ioFs.renameSync(`${backupBase}.${index}`, `${backupBase}.${index + 1}`);
+    } catch {
+      // best-effort
+    }
+  }
+  try {
+    ioFs.renameSync(backupBase, `${backupBase}.1`);
+  } catch {
+    // best-effort
+  }
+}
+
+async function rotateConfigBackups(configPath: string, ioFs: typeof fs.promises): Promise<void> {
+  if (CONFIG_BACKUP_COUNT <= 1) return;
+  const backupBase = `${configPath}.bak`;
+  const maxIndex = CONFIG_BACKUP_COUNT - 1;
+  await ioFs.unlink(`${backupBase}.${maxIndex}`).catch(() => {
+    // best-effort
+  });
+  for (let index = maxIndex - 1; index >= 1; index -= 1) {
+    await ioFs.rename(`${backupBase}.${index}`, `${backupBase}.${index + 1}`).catch(() => {
+      // best-effort
+    });
+  }
+  await ioFs.rename(backupBase, `${backupBase}.1`).catch(() => {
+    // best-effort
+  });
+}
+
 export type ConfigIoDeps = {
   fs?: typeof fs;
   json5?: typeof JSON5;
@@ -165,10 +214,13 @@ export function createConfigIO(overrides: ConfigIoDeps = {}) {
 
     deps.fs.writeFileSync(tmp, json, { encoding: "utf-8", mode: 0o600 });
 
-    try {
-      deps.fs.copyFileSync(configPath, `${configPath}.bak`);
-    } catch {
-      // best-effort
+    if (deps.fs.existsSync(configPath)) {
+      rotateConfigBackupsSync(configPath, deps.fs);
+      try {
+        deps.fs.copyFileSync(configPath, `${configPath}.bak`);
+      } catch {
+        // best-effort
+      }
     }
 
     try {
@@ -344,7 +396,7 @@ export function createConfigIO(overrides: ConfigIoDeps = {}) {
           raw,
           parsed: parsedRes.parsed,
           valid: false,
-          config: {},
+          config: coerceConfig(parsedRes.parsed),
           hash,
           issues: [{ path: "", message }],
           legacyIssues: [],
@@ -366,7 +418,7 @@ export function createConfigIO(overrides: ConfigIoDeps = {}) {
           raw,
           parsed: parsedRes.parsed,
           valid: false,
-          config: {},
+          config: coerceConfig(resolved),
           hash,
           issues: [{ path: "", message }],
           legacyIssues: [],
@@ -379,17 +431,13 @@ export function createConfigIO(overrides: ConfigIoDeps = {}) {
 
       const validated = validateConfigObject(resolvedConfigRaw);
       if (!validated.ok) {
-        const resolvedConfig =
-          typeof resolvedConfigRaw === "object" && resolvedConfigRaw !== null
-            ? (resolvedConfigRaw as ClawdbotConfig)
-            : {};
         return {
           path: configPath,
           exists: true,
           raw,
           parsed: parsedRes.parsed,
           valid: false,
-          config: resolvedConfig,
+          config: coerceConfig(resolvedConfigRaw),
           hash,
           issues: validated.issues,
           legacyIssues,
@@ -450,9 +498,12 @@ export function createConfigIO(overrides: ConfigIoDeps = {}) {
       mode: 0o600,
     });
 
-    await deps.fs.promises.copyFile(configPath, `${configPath}.bak`).catch(() => {
-      // best-effort
-    });
+    if (deps.fs.existsSync(configPath)) {
+      await rotateConfigBackups(configPath, deps.fs.promises);
+      await deps.fs.promises.copyFile(configPath, `${configPath}.bak`).catch(() => {
+        // best-effort
+      });
+    }
 
     try {
       await deps.fs.promises.rename(tmp, configPath);