@onflow/util-logger

Logger for FCL-JS.

Status

• Last Updated: March 30 2022
• Stable: Yes
• Risk of Breaking Change: No

Install

npm install --save @onflow/util-logger

Usage

Logger Levels

| Name | Value | | ------- | ----- | | error | 1 | | warn | 2 | | log | 3 | | info | 4 | | debug | 5 |

import * as logger from "@onflow/util-logger"

// This will fire if the config "logger.level" value is set to the error level or above
logger.log({
  title: "Title of error", 
  message: "Message body", 
  level: logger.LEVELS.error
})

Deprecation

This package also exposes a useful method for logging deprecation warnings via log.deprecate. The function accepts an object with the following keys as its parameters.

• pkg (optional) - The package which the deprecated feature belongs to (i.e. FCL/SDK, @onflow/util-invariant, etc.). If not provided it defaults to an empty string and will not show in the notice.
• subject (optional) - The feature that is being deprecated (i.e. "Passing a start and end into getEvents").
• transition (optional) - The URL to the transition guide for the deprecation
• level (optional) - The logger level of the deprecation notice (default LEVELS.warn)
• message (optional) - An additional message to provide the user about the deprecation. Will ap
• callback (optional) -

Deprecation notice format:

 `${pkg} Deprecation Notice
============================

${subject} is deprecated and will cease to work in future releases of ${pkg}.
${message}
You can learn more (including a guide on common transition paths) here: ${transition}

============================`

The lines with subject, message, and transition will not appear if these values are not provided.

Example usage:

import * as logger from "@onflow/util-logger"

logger.log.deprecate({
  pkg: "FCL/SDK",
  subject: "Passing a start and end into getEvents",
  transition:
    "https://github.com/onflow/flow-js-sdk/blob/master/packages/sdk/TRANSITIONS.md#0005-deprecate-start-end-get-events-builder",
})