Support for labels

[kylehayes]

I added support for labels which by itself was a pretty simple change by passing the labelFilter property into listConfigurationSettings. When running this in production for our system, however, the Azure credentials were not being picked up from our container's environment. I realized this was because the credentials were not read from process.env when loading in config(). I added support for this which required some typing change since it was no longer the same shape as DotenvParseOutput.

I'm not married to any of this so open to any suggestions. Thanks for creating this project!

[danielfsousa]

Looks good to me, just need to add some tests and update the README.md before merging.

Thank you for your contribution!

[kylehayes]

Sounds great! I've made the changes locally per your suggestions. I'll add some tests and update the README within the week.

[kylehayes]

I added a test to ensure config doesn't throw if labels are defined. I'm not sure if or what other tests you might be looking for to test the label filtering functionality. I'm not very experience with mocks so any direction or assistance you can provide with awesome.

[danielfsousa]

I added a test to ensure config doesn't throw if labels are defined. I'm not sure if or what other tests you might be looking for to test the label filtering functionality. I'm not very experience with mocks so any direction or assistance you can provide with awesome.

We could use the toBeCalledWith function to assert that we are passing the AZURE_APP_CONFIG_LABELS to client.listConfigurationSettings():

expect(appConfigListMock).toBeCalledWith(
  expect.objectContaining({
    labelFilter: AZURE_APP_CONFIG_LABELS,
  })
)

[danielfsousa]

Another good feature to have is allowing the label filter to be defined programmatically, just like the connectionString:

dotenv-azure/src/dotenv-azure.ts

Line 208 in 0ca5e6c

const connectionString = this.connectionString || vars.AZURE_APP_CONFIG_CONNECTION_STRING

Then we could use it like this:

await dotenvAzure.config({ labels: 'production,development' })

or

await dotenvAzure.config({ labels: ['production', 'development'] })

[danielfsousa]

The CI is failing because of prettier, just run the script below, commit the changes and it should be fixed:

npm run format