Object mutation

[miljan-aleksic]

Hi @alexsasharegan,

in my local tests I am getting this strange behavior where the passed in objects are being mutated.
Example

const def = {on: { event }}
const def2 = {on: { event2 }}

const data = dataMerge(data, def, def2)

console.log(def) // { on: [event, event2] }

Before making some deeper tests and solutions I wanted to expose this issue and see if there is any reason behind.

Thank you.

[alexsasharegan]

Good catch. The first argument passed to the function gets copied into a fresh target object, but it's a shallow copy. I'll work on a fix today.

@miljan-aleksic, would you be able to post a minimum reproducible scenario? I'm going to add testing for the function and I'd like to add a test tagged with this issue number.

Update: You can view the tests to see if your case is covered sufficiently.

[alexsasharegan]

This has been fixed in v2. Consult the changelog for info on upgrading. Basically you just need to use named imports now, and everything else works.

Also, thanks for the mention on the vuejs repo (vuejs/vue#6895), @miljan-aleksic! I would love for this to be exposed from vue itself.

[miljan-aleksic]

Awesome! The tests were absolutely necessary and thanks for the fix!!

Although, I wasn't able to test it as the compiled dist code is not converted to ES5 entirely. There is a spread operator present at function mergeData(...e).

Yes, hopefully, Vuejs team will take it into serious consideration. Thanks for your hard work!

[alexsasharegan]

Hmm... I'll figure out how the transpilation failed. Fix coming shortly!

[alexsasharegan]

I let the function type signature in the live function. My bad! All fixed.

[miljan-aleksic]

Sorry, I got confused about the real issue, although I'm glad we found another one meantime :D

I am recompiling your code into my core lib using rollup (that way I don't add more dependencies) and I am getting this error from rollup CompileError: for...of statements are not supported..

I checked the dist quickly and saw the spread and assumed... but the issue was actually the for...of. That was my bad :)

[alexsasharegan]

Ah, looks like I tweaked the wrong tsconfig.json setting. Flipped that back to es5 to transpile the for of statements.

You don't need to compile this one from source if you don't want to since it holds no dependencies. But if you do, you'll need to wire up typescript with a similar config.

[miljan-aleksic]

Actually, I am just reexporting, not recompiling and now is working as expected. The objects are not being mutated, the code is well transpiled, perfect, thank you so much!

[alexsasharegan]

Excellent! Thanks for being a patient beta tester!