transkey v0.1.1

transkey

Object -> Object with keys translated by translator function or dictionary object.

API

transkey(dict, src, dest)

Copy values from src to dest, to keys translated by dict. If dest is false-y (e.g. because missing), a new object is created.

dict should be either…

• a function that returns the translation of its first argument
• an object that maps old keys to new keys
• "dash2camel": foo-bar -> fooBar
• "lc": lowercase
• "uc": UPPERCASE

Some translations have special effects:

• null, undefined: Use the original key name.
• false: Omit that key.

Usage

from test/usage.js:

var tok = require('transkey'),    // tok = translate object keys
  obj = {
    Hello: 'World',
    '': 'empty',
    'main dish': 'pork & beans',
    'content-type': 'text/plain',
  };

expectEqual(tok('uc', obj), {
  HELLO: 'World',
  '': 'empty',
  'MAIN DISH': 'pork & beans',
  'CONTENT-TYPE': 'text/plain',
});

expectEqual(tok('dash2camel', obj), {
  Hello: 'World',
  '': 'empty',
  'main dish': 'pork & beans',
  'contentType': 'text/plain',
});

expectEqual(tok('dash2camel', {
  'double--dash': 'd--d',
  '-': -1,
  '-f': 'force',
  'é-é': 'eacute',
  '--': -2,
}), {
  'double-Dash': 'd--d',
  '-': -1,
  F: 'force',
  'é-é': 'eacute',
  '--': -2,
});

function strlen(s) { return s.length; }
expectEqual(tok(strlen, obj), {
  '0': 'empty',
  '5': 'World',
  '9': 'pork & beans',
  '12': 'text/plain',
});

function ifOdd(n) { return ((+n % 2) ? n : false); }
function oddLength(s) { return ifOdd(s.length); }
expectEqual(tok(oddLength, obj), {
  '5': 'World',
  '9': 'pork & beans',
});

expectEqual(tok({
  '': 'nothing',
  'content-type': false,
  'main dish': [ null, 'spaghetti' ],
  Hello: [ 'How', 'are you?' ],
}, obj), {
  How: 'are you?',
  'main dish': 'spaghetti',
  nothing: 'empty',
});

Known issues

• needs more/better tests and docs

License

ISC