regular expression used as defaults value of a module, is corrupted.

[eouia]

Recently, I found that when the regular expression is used as the default config value of a module, it would be corrupted.
I think it comes from configMerge or somewhere, but I cannot track exactly where the issue lies.

How to represent/prove

set some fields in defaults of MODULENAME.JS and config of config.js

// In module file
Module.register("TEST", {
  defaults: {
    rex_default1: /ab+c/,
    rex_default2: [ 'ab+c', /ab+c/, new RegExp('ab+c') ],
    rex_config1: null,
    rex_config2: [],
...

// in config.js
{
  module: 'TEST',
  config: {
    rex_config1: /ab+c/,
    rex_config2: [ 'ab+c', /ab+c/, new RegExp('ab+c') ],
...
//

Let's check which values are there.

start: function () {
    console.log(this.config)
}

The Result;

[sdetweil]

more than likely the merge under the covers does stringify which DOES NOT handle code expressions by default.

I had to fix this same problem in my mmm-config module

[sdetweil]

well, the default is Object.assign() which only does shallow copy and only enumerable items.

[eouia]

It doesn't matter.
General Object.assign() itself do it's role well.

I think JSON.stringify() somewhere for deepMerging or whatever makes this issue.

[sdetweil]

is that the same data as the new RegExp() which you reported in first message?

[eouia]

??? sorry, I cannot catch your question.

In my original post,
rex_config1 and rex_config2 were imported from 'config.js' and overrided as expected.
But,
rex_default1 and rex_default2 were corrupted. They should remain but changed as /(?:)/, and this value would definitely be derived from new RegExp(false|null|undefined). So I guess somewhere JSON.stringify fails to convert proper string, so it might have undefined or false then tried to revamp RegExp Object from it.

[sdetweil]

config.js is parsed by JavaScript( in the browser by the script tag) and is an object, not a string, the new RegExp() is converted to an object, the output of the new . I believe this is actually a function object, which stringify doesn't handle be default
index.html

    <script type="text/javascript" src="js/defaults.js"></script>
    <script type="text/javascript" src="#CONFIG_FILE#"></script>    <------
    <script type="text/javascript" src="vendor/vendor.js"></script>

[eouia]

So, is this not a bug and designed as expected? A module cannot get a regular expression object as a default value.
If so, OK.

[sdetweil]

i would try to set the deepMerge: true option and see if that makes a difference.. it doesn't use Object.assign()

I don't know if its a 'bug'.. there are no default modules that have code in their config settings..

but my pythonPrint does

transform:(data)=>{return data.replace(/\n/g,"<br>")}

and that gets processed correctly..

[eouia]

Yes, I can avoid this problem by assigning regexp objects in code (usually start()) manually when the user configuration is not overriding them. It is just a little annoying and unexpected behaviour. That's all.

[sdetweil]

the setting to add to your module before config is

 configDeepMerge: true,

[khassel]

the problem is this line in js/module.js, before cloneObject the values are o.k., after the call they are corrupted.

the cloneObject function is defined in js/class.js here.

[khassel]

we have already a working function to clone config objects, so replacing

	const clonedDefinition = cloneObject(moduleDefinition);

with

	const clonedDefinition = configMerge(moduleDefinition);

works.

Will do more tests and provide a PR tomorrow.