debugging.md

id	title	description
debugging	Debugging	This document describes how to debug the reSolve framework and reSolve-based applications.

ReSolve uses the @resolve-js/debug-levels package to log debug information. This package extends the debug library's functionality with the following logging levels:

Level	Description
log	Messages that should always be displayed
error	Errors that can prevent normal program execution
warn	Potential problems in the application's implementation
debug	Information displayed for debugging purposes
info	Messages that describe the current operation
verbose	Extended descriptions to the previous message

The reSolve framework uses the debug logging level by default. Set the DEBUG_LEVEL environment variable to use a different logging level.

Debug ReSolve

The reSolve framework uses the resolve prefix for all its debugging namespaces. To enable the framework's debug output, assign resolve* to the DEBUG environment variable as shown below:

DEBUG=resolve:* DEBUG_LEVEL=error yarn dev

Debug a ReSolve Application

You can add the @resolve-js/debug-levels package to your application's dependencies to use @resolve-js/debug-levels to debug your reSolve application.

yarn add @resolve-js/debug-levels

To create a logger, pass your module's debugging namespace to the function the @resolve-js/debug-levels module exposes:

import debugLevels from '@resolve-js/debug-levels'
const log = debugLevels('myapp:api-handlers')
...

The logger object exposes methods that correspond to the available debug levels:

...
log.debug('processing an API request')
log.verbose(`request body: ${JSON.stringify(req.body)}`)
log.verbose(`cookies: ${JSON.stringify(req.cookies)}`)
...

Use the DEBUG and DEBUG_LEVEL environment variables to enable debug messages:

DEBUG=myapp:api-handlers DEBUG_LEVEL=verbose yarn dev