Add default connection attributes

[Daemonxiao]

MySQL connectors have some Available Connection Attributes.

I add the following built-in connection attributes to Node-MySQL-2.

{
  '_client_name': 'Node-MySQL-2',
  '_client_version': version
}

These attributes will help users distinguish which driver the connection comes from.

[sidorares]

LGTM, thanks for adding this @Daemonxiao

could you link mysql docs in a comment and add few words explaining what/why these attributes are ( and that names are not something we made up and are common agreed )

Also can you rewrite a commit message to follow https://www.conventionalcommits.org/en/v1.0.0/

( also - might need to rebase once again a bit later, currently PlanetScale check is failing for some reason. I'll try to fix or disable that today )

[Daemonxiao]

@sidorares Thanks for your review. I have rewritten the commit message. Does it meet the requirements? Please feel free to tell me if you have any advice.

[sidorares]

Does it meet the requirements? Please feel free to tell me if you have any advice.

Yep, perfect. release-please is using commit messages to automatically populate feature / release / chore section of the release post, and also only prepares a release if there a new "releasable items" since the last one.

[sidorares]

Maybe it's better to move the change to connection_config, where other default connection parameters are
Also maybe worth leaving a way to override attributes if they are passed, for example here

node-mysql2/lib/connection_config.js

Line 172 in 2c1b4bc

this.connectAttributes = options.connectAttributes;

use line like

const defaultConnectAttributes =  {
  _client_name: 'Node-MySQL-2',
  _client_version: version
};
this.connectAttributes = { ...defaultConnectAttributes, ...(options.connectAttributes || {}));

[Daemonxiao]

Maybe it's better to move the change to connection_config, where other default connection parameters are
Also maybe worth leaving a way to override attributes if they are passed, for example here

@sidorares Thank you very much. This really excellent advice. I have applied it in nearly commit.

[sidorares]

@Daemonxiao some unit tests are failing, could you try running them locally?

[Daemonxiao]

some unit tests are failing, could you try running them locally?

@sidorares Done.

[Daemonxiao]

@sidorares Is this pr ready to be merged? Or is there anything else I can do?