---
url: https://masyaka.github.io/injecute/errors/wiring-failed.md
description: The wiring check found services that are missing or fail
---

# `INJECUTE_WIRING_FAILED`

**The wiring check found services that are missing or fail.**

## How to fix it

Every problem is listed in the message and in error.problems. Register the missing keys (check for typos and for modules that were not applied), and fix the factories that failed: their errors are in each problem and in cause (an AggregateError).

## Example

```ts
const app = new DIContainer()
  .addSingleton('db', () => connect(process.env.DATABASE_URL))
  .addSingleton('users', UserRepository, ['db'])
  .addSingleton('notifications', Notifications, ['mailer']); // nothing registers "mailer"

await checkWiring(app, { resolve: true });
// WiringError: The wiring check found 2 problems:
//   - "mailer" is not registered. Needed by "notifications".
//   - "db" failed: DATABASE_URL is not set. Not resolved because of it: "users".
```

## Reading it

* **Not registered:** a dependency key, or a key passed in `keys`, that no container registers. Check
  the key for typos, and that the module that registers it is applied. The services listed need it,
  directly or through other services.
* **Failed:** resolving the service threw. The services listed depend on it and were skipped, so each
  failure is reported once. The original error is in the problem's `error`, and every failure is in
  `cause` (an `AggregateError`).

`error.problems` has the same list as data, for example to assert on it:

```ts
expect(error.problems).toEqual([
  { type: 'missing', key: 'mailer', affected: ['notifications'] },
  expect.objectContaining({ type: 'failed', key: 'db', affected: ['users'] }),
]);
```

See [Check the wiring](../guide/testing.md#check-the-wiring).

## Handling it in code

```ts
import { InjecuteError } from 'injecute';

try {
  // ...
} catch (error) {
  if (error instanceof InjecuteError && error.code === 'INJECUTE_WIRING_FAILED') {
    // error.message explains what happened; error.path is the resolution chain
  }
}
```

[All error codes](./index.md)