keepDefined

Copies only the keys whose values are defined.

keepDefined<TObject, TKey>(
    source: TObject,
    keys: readonly TKey[]
): Partial<
    Pick<
        TObject,
        TKey extends never ? keyof TObject : TKey
    >
>

keepDefined<TObject, TKey>(
    source: TObject,
    keys: readonly TKey[]
): Partial<
    Pick<
        TObject,
        TKey extends never ? keyof TObject : TKey
    >
>

interface Config {
  host?: string;
  port?: number;
  user?: string;
  password?: string;
}

const config: Config = {
  host: 'localhost',
  port: undefined,
  user: 'admin',
  password: undefined
};

const definedConfig = keepDefined(config, 'host', 'port', 'user', 'password');
// Result: { host: 'localhost', user: 'admin' }

interface Config {
  host?: string;
  port?: number;
  user?: string;
  password?: string;
}

const config: Config = {
  host: 'localhost',
  port: undefined,
  user: 'admin',
  password: undefined
};

const definedConfig = keepDefined(config, 'host', 'port', 'user', 'password');
// Result: { host: 'localhost', user: 'admin' }

TObject

the original object type you're pulling from

TObject

TObject

the original object type you're pulling from

TKey

the keys to copy when defined

TKey

TKey

the keys to copy when defined

source

source: TObject

source: TObject

the object to read values from

keys

keys: readonly TKey[]

keys: readonly TKey[]

optional list of keys to include when present. If omitted, all keys are considered