New DebugLogger

[pravdomil]

Motivation

The debug package is the 9th most dependent package, it's used by express, koa, yeoman, babel, mocha, socket.io, eslint, morgan and more. It works in both node.js and browser.
#634 #633

What's new

• ConnectOptions.logger has new value "debug"
• New debug namespaces introduced:

typeorm:query
typeorm:queryError
typeorm:querySlow
typeorm:schemaBuild
typeorm:migration
typeorm:log
typeorm:info
typeorm:warn

Drawbacks

• Debug dependency (debug itself has only one dependency, module ms)
• ConnectOptions.logging?: LoggerOptions is no longer used.
  You need set env variable DEBUG=typeorm:* or call debug.enable('typeorm:*'); in order to set log level.

Benefits

• TypeORM log fits nicely next to others.
• You can start debugging every aspect of application by setting DEBUG=* and logger: "debug".

Example

Here's rest api example, I got a get request and then it reports which query TypeORM executed.

Discussion

• Use it as default logger and deprecate logging option and control everything via debug lib. That's basically how express does logging.
• Documentation changes

[pleerock]

we need to dynamically load any third-party package using require from PlatformTools class. Its requirement for typeorm to be cross-platform

[pravdomil]

import * as path from "path";

/**
 * Platform-specific tools.
 */
export class PlatformTools {
    ...
		
    /**
     * Debug module needed by DebugLogger
     */
    static debug = debug;
}

like that? what do you prefer?

[pleerock]

no, just see how many other libraries like mkdirp, redis, mysql, etc. are loaded using PlatformTools, its dynamic loading using require function

[pravdomil]

ahh you meant PlatformTools.load

[pleerock]

remove it

[pleerock]

typeorm:queryError

queryError looks rough, is there naming convention in debug? Maybe better name it typeorm:query:error or typeorm:query-error ?

[pravdomil]

https://github.com/visionmedia/debug#conventions

[pleerock]

Thank you for your contribution, can you please update documentation and changelog for the next version as well

[pravdomil]

what is the next version number?

[pleerock]

0.1.8

[pravdomil]

maybe we can change typeorm:query* debug namespace to

typeorm:query:log
typeorm:query:error
typeorm:query:slow

and

typeorm:schemaBuild to typeorm:schema