Update Precendence order documentation according implementation

[zaverden]

Fixes #211
Fixes #208

[coveralls]

Coverage remained the same at 100.0% when pulling 18b9c89 on zaverden:patch-1 into 9f2b2d3 on mozilla:master.

[zaverden]

@A-312 could you check this out please? this is a documentation update according our discussion in #211. Does it look OK, or I should change it to be more clear?

[A-312]

I don't know, after looking this part, I don't like the current integration. We should have something like that : config.loadExternal(['env', 'arg']). Or rewrite all the content of this paragraph.

After a long reflection, I think this can be better :

When merging configuration values from different sources, Convict follows precedence rules. The order, from lowest to highest, for config.loadFile(file) and config.load(json) is :

1. Default value ;
2. File or json set in function argument ;
3. Environment variables (only used when env property is set in schema) ;
4. Command line arguments (only used when arg property is set in schema).

Environment variables and Command line arguments can be overridden using the env or args option of the convict function convict(schema, {env: {}, arg: {}}) ???? <--- check this part

I don't understand : can be overridden using the env|args option of the convict function -> I think this part is not in the doc. If I understand we can do convict(schema, opt), is not it ?

We speak only about loadFile and load because set have priority only if is call after load because :

const config = convict({ port: { default: 3000 } }
config.load({ port: 8080 });
console.log(config.get('port')); // 8080
config.set('port', 433);
console.log(config.get('port')); // 443
config.load({ port: 9000 });
console.log(config.get('port')); // 9000

[zaverden]

@A-312 Thank you for a review. I did not think about complete rewrite of this block, but it make sense in order to make it clear.

I'll update the PR later

[A-312]

ping @zaverden

[zaverden]

@A-312 sorry for delay.

I have updated description and moved can be overridden using the env|args option to a separate section

[A-312]

This PR is ready

[A-312]

@madarche This one is ready

[A-312]

@zaverden Can you rebase your PR in mozilla:feat-multi-packages-split ? Is the branch for the next update (6.0.0).

[zaverden]

@A-312 done