Angular SDK - Custom logging

Supply a logger and the SDK routes its output to it. Without one, output is discarded.

The interface

interface NexusLogger {
  debug(message: string, fields?: Record<string, unknown>): void;
  info(message: string, fields?: Record<string, unknown>): void;
  warn(message: string, fields?: Record<string, unknown>): void;
  error(message: string, fields?: Record<string, unknown>): void;
}

You may implement any subset; missing levels are filled in with no-ops. Values travel in fields, never interpolated into message. A message that embeds its values produces a unique string per occurrence, which cannot be grouped, counted or alerted on. A stable message plus structured fields can. An error is carried as fields.cause.

A console logger

const consoleLogger: NexusLogger = {
  debug: (message, fields) => console.debug('[nexus]', message, fields),
  info:  (message, fields) => console.info('[nexus]', message, fields),
  warn:  (message, fields) => console.warn('[nexus]', message, fields),
  error: (message, fields) => console.error('[nexus]', message, fields),
};

provideNexus({
  baseUrl: 'https://blue-ocean-a5rx7.westyx.dev',
  apiKey: 'wxp_...',
  logger: consoleLogger,
})

What the SDK logs

Level	When
`debug`	A sync applied or not modified, a stream event received, an out-of-order response discarded, the client closed, live updates unavailable in this environment
`info`	The client is ready; the SDK has fallen back to polling
`warn`	A sync is being retried, payment is required, a quarantine, the stream was refused or ended
`error`	The initial sync failed, a sync failed for a reason the SDK does not retry, a consumer callback threw

Records carry fields such as status, attempt, retry_in_ms, configs, flags, key_type, event, consecutive_failures and cause.

Secrets never reach the logger

No log record contains a secret’s value or a secret’s key name, at any level, and no record contains the API key. A test in the SDK drives a sync carrying a secret through a capturing logger at the most verbose level and fails if either appears anywhere in the output. A configuration rejection naming the API key carries only its prefix - wxp_...

never the material.

A logger that throws cannot break the SDK

Every call is guarded. A logger is diagnostic equipment; a broken one does not take the sync loop down with it.

Overview

Backend SDKs

Browser SDKs

OpenFeature Providers

Angular SDK - Custom logging

The interface

A console logger

What the SDK logs

Secrets never reach the logger

A logger that throws cannot break the SDK

​The interface

​A console logger

​What the SDK logs

​Secrets never reach the logger

​A logger that throws cannot break the SDK

The interface

A console logger

What the SDK logs

Secrets never reach the logger

A logger that throws cannot break the SDK