Customise conversion based on some criteria

[domchristie]

As has been noted in other issues/pull requests (#26) the default conversion behaviour does not work in all cases, e.g.

• when the key is all uppercase (Exclude from camelization all-uppercase keys #20)
• when the key starts with an underscore (Do not convert names starting with underscore #22)
• or some other criteria (Add ability to exclude certain keys from processing #26)

Rather than add options for each of these cases, may I propose that just a single option be added that will handle all of the above. Something like:

humps.camelizeKeys(obj, {
  filters: [
    {
      filter: function (key) { return /^[A-Z_]+$/ },
      convert: function (key) { return key }
    },
    {
      filter: function (key) { return /^_/ },
      convert: function (key) { return key }
    },
    {
      filter: function (key) { return ['exclude_me', 'and_me'].indexOf(key) > _1 },
      convert: function (key) { return key }
    }
  ]
})

Although all the conversion functions in these cases simply return the original key unmodified, it may be useful to allow custom conversion e.g. #18.

Thoughts?

/cc @mattkrick, @GiovanniFrigo, @patrickgalbraith, @rufman

[patrickgalbraith]

I like the thinking but I would recommend just doing it with a single callback like this:

humps.camelizeKeys(obj, (key, convert) => {
  return /^[A-Z_]+$/.test(key) ? key : convert(key)
})

That way you can just do the above like:

humps.camelizeKeys(obj, (key, convert) => {
  const tests = [/^[A-Z_]+$/, /^_/, /(exclude_me|and_me)/]
  return tests.some((re) => re.test(key)) ? key : convert(key)
})

In my opinion I still think #22 should be merged. But if not I can do this to fix it (at least the starts with underscore part).

humps.camelizeKeys(obj, (key, convert) => {
  return key.charAt(0) === '_' ? '_' + convert(key) : convert(key)
})

[GiovanniFrigo]

I agree with @patrickgalbraith, having a single callback makes the code more synthetic and flexible.

I'd still merge in #20 and #22 because it doesn't make much sense to have all-uppercase or underscore-starting keys camelized as it is right now.

[patrickgalbraith]

@domchristie What do you think of #28?