Feat. New option ignoreFunction according to issue#32

[realdennis]

I confirm that this contribution is made under the terms of the license found in the root directory of this repository's source tree and that I have the authority necessary to make this contribution on behalf of its copyright owner.

According to this issue #32 , I add a new option ignoreFunction for serialize.

function fn(){ return true; }
serialize( fn , { ignoreFunction:true}) // 'undefined'
serialize({
    num:123,
    fn
},{ignoreFunction:true}); // `{"num":123}`

• Add feature
• Write test case
• Update document

[realdennis]

Actually I wrote this first

    Object.keys(obj)
    .filter(key => typeof obj[key] === "function")
    .forEach(functionKey => {
      delete obj[functionKey];
    });

But I have no idea what the lowest browser the code should support to,
so I avoid to use Object.keys

[tom76kimo]

Could @redonkulus help review this?

[realdennis]

@tom76kimo Thanks for reminding me.

[realdennis]

@okuryu Updated, thanks!

[realdennis]

@okuryu By the way, there is some inconsistent style in the original code.

2 space indents
https://github.com/yahoo/serialize-javascript/blob/master/index.js#L91-L95

4 space indents
https://github.com/yahoo/serialize-javascript/blob/master/index.js#L51-L60

Maybe we should make a new pull request or issue to discuss about coding style, like lint check using ESLint, and some helpful config like .eslintrc and .prettierrc in the future.

[okuryu]

yeah, I'll try to format with prettier separately.

[okuryu]

Okay, I'll work on merging and release on this until the end of tomorrow If there are no other comments.

[okuryu]

published v2.1.0. Thanks!