env-prefix-map

Function that:

• gets all the keys with given prefix
• removes that prefix
• (by default) lowercases the keys

Usage

The function is provided to create map out of env variables. Eg, for env variables:

PLAYS_CHELLO='Mark'
PLAYS_VIOLIN='Mary'
PLAYS_GUITAR='Jimmy'
SOME_VARIABLE='x'

the call

require('env-prefix-map')(process.env, 'PLAYS_');

would produce a map of following form:

{
    chello: 'Mark',
    violin: 'Mary',
    guitar: 'Jimmy'
}   

Variations:

Change keys

One can differentiate the way key is being tranformed (toLowerCase by default):

require('env-prefix-map')(process.env, 'PLAYS_', {keyFn: k => 'plays ' + k});

will produce:

{
    'plays chello': 'Mark',
    'plays violin': 'Mary',
    'plays guitar': 'Jimmy'

}

Change values

You can also transform values:

require('env-prefix-map')(process.env, 'PLAYS_', {valueFn: v => v.toUpperCase()});

will produce:

{
    chello: 'MARK',
    violin: 'MARY',
    guitar: 'JIMMY'
}