Function makeNestedConfig

makeNestedConfig<
    C extends object = Record<string, any>,
    F = Record<string, string>,
>(
    _flatConfig: F,
    opts?: MakeNestedConfigOpts,
): {
    allConfigs: () => C;
    getConfig: <P extends string, D>(
        path: P,
        defaultValue?: D,
    ) => PathValue<C, P>;
}

Loads the flatmap variables and returns a config object. Coerces values to the correct types based on guessing from the value itself. For example, if the value is "true", it will be converted to a boolean true, if it's "123", it will be converted to a number 123, etc.

Type Parameters

C extends object = Record<string, any>
F = Record<string, string>

Parameters

_flatConfig: F
opts: MakeNestedConfigOpts = {}
Optional options object
- Optionalfilter?: (key: string, value: string) => boolean
- OptionalforceAllCapToLower?: boolean
- OptionalmemoizeOpts?: false | MemoizeOptions<any>
- OptionalparseUnits?: boolean
- Optionalseparator?: string
- OptionalskipConversion?: (key: string, value: unknown) => boolean
- OptionalstripPrefix?: string | number

Returns {
    allConfigs: () => C;
    getConfig: <P extends string, D>(
        path: P,
        defaultValue?: D,
    ) => PathValue<C, P>;
}

The full configuration object.

Example

// Assuming process.env contains:
// {
//     APP_DB_HOST: 'localhost',
//     APP_DB_PORT: '5432',
//     APP_DEBUG: 'true',
//     APP_FEATURE_X_ENABLED: 'false'
//     APP_WORKER_EMAILS_maxRunsPerMin: '100'
//     APP_WORKER_EMAILS_networkTimeoutMs: '100'
// }

const config = makeNestedConfig(process.env, {
    filter: (key) => key.startsWith('APP_'),
    stripPrefix: 'APP_',  // Strip the APP_ prefix from all keys
    forceAllCapToLower: true,
    separator: '_',
    memoizeOpts: { ttl: 60000 } // Cache for 60 seconds
});

console.log(config());
// {
//     db: {
//         host: 'localhost',
//         port: 5432
//     },
//     debug: true,
//     feature: {
//         x: {
//             enabled: false
//         }
//     },
//     worker: {
//         emails: {
//             maxRunsPerMin: 100,
//             networkTimeoutMs: 100
//         }
//     }
// }

Example

// Using a custom separator
// Assuming process.env contains:
// {
//     APP_DB__HOST: 'localhost',
//     APP_DB__PORT: '5432',
//     APP_DEBUG: 'true',
//     APP_FEATURE__X_ENABLED: 'false',
//     APP_WORKER__EMAILS__maxRunsPerMin: '100'
//     APP_WORKER__EMAILS__networkTimeoutMs: '100'
// }
const config = makeNestedConfig(process.env, {
    filter: (key) => key.startsWith('APP_'),
    stripPrefix: 'APP_',  // Strip the APP_ prefix
    forceAllCapToLower: true,
    separator: '__'
});

console.log(config());
// {
//     db: {
//         host: 'localhost',
//         port: 5432
//     },
//     debug: true,
//     feature: {
//         x_enabled: false
//     },
//     worker: {
//         emails: {
//             maxRunsPerMin: 100,
//             networkTimeoutMs: 100
//         }
//     }
// }

Example

// Not forcing all-caps to lowercase
// Assuming process.env contains:
// {
//     APP_DB_HOST: 'localhost',
//     APP_DB_PORT: '5432',
//     APP_DEBUG: 'true',
//     APP_FEATURE_X_ENABLED: 'false'
//     APP_WORKER_EMAILS_maxRunsPerMin: '100'
//     APP_WORKER_EMAILS_networkTimeoutMs: '100'
// }

const config = makeNestedConfig(process.env, {
    filter: (key) => key.startsWith('APP_'),
    stripPrefix: 'APP_',  // Strip the APP_ prefix
    forceAllCapToLower: false,
    separator: '_'
});

console.log(config());
// {
//     DB: {
//         HOST: 'localhost',
//         PORT: 5432
//     },
//     DEBUG: true,
//     FEATURE: {
//         X_ENABLED: false
//     },
//     WORKER: {
//         EMAILS: {
//             maxRunsPerMin: 100,
//             networkTimeoutMs: 100
//         }
//     }
// }

Example

// Using parseUnits to convert time and byte values
// Assuming process.env contains:
// {
//     APP_SESSION_TIMEOUT: '15m',
//     APP_CACHE_TTL: '1hour',
//     APP_MAX_UPLOAD_SIZE: '10mb',
//     APP_DISK_QUOTA: '100gb'
// }

const config = makeNestedConfig(process.env, {
    filter: (key) => key.startsWith('APP_'),
    stripPrefix: 'APP_',
    parseUnits: true  // Enable unit parsing
});

console.log(config());
// {
//     session: {
//         timeout: 900000  // 15 minutes in milliseconds
//     },
//     cache: {
//         ttl: 3600000  // 1 hour in milliseconds
//     },
//     max: {
//         upload: {
//             size: 10485760  // 10 megabytes in bytes
//         }
//     },
//     disk: {
//         quota: 107374182400  // 100 gigabytes in bytes
//     }
// }

Example

// Using skipConversion to keep certain values as strings
// Assuming process.env contains:
// {
//     APP_API_KEY: '12345',
//     APP_SECRET_TOKEN: '67890',
//     APP_PORT: '3000',
//     APP_DEBUG: 'true'
// }

const config = makeNestedConfig(process.env, {
    filter: (key) => key.startsWith('APP_'),
    stripPrefix: 'APP_',
    skipConversion: (key) => key.toLowerCase().includes('key') || key.toLowerCase().includes('token')
});

console.log(config());
// {
//     api: {
//         key: '12345'  // Kept as string
//     },
//     secret: {
//         token: '67890'  // Kept as string
//     },
//     port: 3000,  // Converted to number
//     debug: true  // Converted to boolean
// }

Function makeNestedConfig

Type Parameters

Parameters

`Optional`filter?: (key: string, value: string) => boolean

`Optional`forceAllCapToLower?: boolean

`Optional`memoizeOpts?: false | MemoizeOptions<any>

`Optional`parseUnits?: boolean

`Optional`separator?: string

`Optional`skipConversion?: (key: string, value: unknown) => boolean

`Optional`stripPrefix?: string | number

Returns {
    allConfigs: () => C;
    getConfig: <P extends string, D>(
        path: P,
        defaultValue?: D,
    ) => PathValue<C, P>;
}

Example

Example

Example

Example

Example

Settings

Function makeNestedConfig

Type Parameters

Parameters

Optionalfilter?: (key: string, value: string) => boolean

OptionalforceAllCapToLower?: boolean

OptionalmemoizeOpts?: false | MemoizeOptions<any>

OptionalparseUnits?: boolean

Optionalseparator?: string

OptionalskipConversion?: (key: string, value: unknown) => boolean

OptionalstripPrefix?: string | number

Returns { allConfigs: () => C; getConfig: <P extends string, D>( path: P, defaultValue?: D, ) => PathValue<C, P>;}

Example

Example

Example

Example

Example

Settings

`Optional`filter?: (key: string, value: string) => boolean

`Optional`forceAllCapToLower?: boolean

`Optional`memoizeOpts?: false | MemoizeOptions<any>

`Optional`parseUnits?: boolean

`Optional`separator?: string

`Optional`skipConversion?: (key: string, value: unknown) => boolean

`Optional`stripPrefix?: string | number

Returns {
allConfigs: () => C;
getConfig: <P extends string, D>(
path: P,
defaultValue?: D,
) => PathValue<C, P>;
}