Is it possible to force a reload of the config?

[nickminutello]

I am writing a test for our various different configurations - to ensure that after all the different host/environment/etc configs are loaded and merged, we end up the final config we expect.

e.g.
_.each(configs, function(envConfig){
var actualConfig = require(envConfig);
var expectedConfig = readExpectedConfig(envConfig);
test.deepEqual(actualConfig, expectedConfig);
test.done();
})

(I'm manipulating environment variables to

However, I cant seem to load more than 1 config because of the singleton nature of it.
Is there a way to do it already?
If not, should we add one?

[lorenwest]

It is designed to have one config per application instance, with the singleton pattern used so different sub-modules can share a common configuration.

In your case, you may be able to reset configs by setting environment variables, then calling global.NODE_CONFIG = new Config(); in your loop (assuming you've set Config = require('config') at the top of your test).

It's not designed for that, but that might get you what you need. I'm hesitant to build-in support for multiple configs because it seems like a test-only situation.

Let me know if that works for you.

[nickminutello]

Config = require('config')
global.NODE_CONFIG = new Config();

No, that doesnt work.
TypeError: object is not a function.
module.exports is assigned the config object - not a function.

It is designed to have one config per application instance, with the singleton
pattern used so different sub-modules can share a common configuration.
I'm hesitant to build-in support for multiple configs because it seems like a test-only situation.

I understand the intent of the singleton - and the simplicity of use across modules.
But being able to test is also important for us.
We have 6 different environments (2 prod/uat & 3 regions) - and are using all levels of config available (default + env + host).
Without tests I'm finding it hard to re-factor or reorganise our config without introducing inadvertent changes...

[lorenwest]

Here's another approach - The config module is cached by Node in the require module. Theoretically you should be able to remove all traces and reload by doing this within your loop:

...reset your environment variables...
global.NODE_CONFIG = null;
delete require.cache.config;
var config = require('config');
...test the new configs...

Testing is very important - let me know how this works for you.

[nickminutello]

That works with one small change. Instead of delete.require.cache.config, we need:

    delete require.cache[require.resolve('config')];

Thanks!

[lorenwest]

Glad we came up with a solution - thanks for your help as well!