js/console: Marshal by default native JS objects

[codebien]

Closes #1146

⚠️ BREAKING CHANGE: After this PR will be merged, all js/console methods like console.log and console.info, in the case a JavaScript Object (or an Array) is passed as an argument then it is converted into a string encoded as a JSON object.

Objects

export default function () {
  var user = [{}]

  console.log("the user", user) 
  // before: the user [object Object]
  // after: the user {"name":"Bob"}
}

Arrays

export default function () {
  var user = {name: "Bob"}

  console.log([1, 2, "mytest", {user: "Bob"}]) 
  // before: 1,2,mytest,[object Object]
  // after: [1,2,"mytest",{"user":"Bob"}]
}

The previous way can be restored by directly parsing the object to a string using the String function.

export default function () {
  var user = {name: "Bob"}
  console.log(String(user)) 
}

[mstoykov]

@codebien does this still happen with your code #644 (comment)

[oleiade]

I have tried the branch locally, and I think I've spotted some missing supported cases? Namely, it seems that as of this PR's state, JSON arrays are not properly supported, nor are arrays with mixed type values. Moreover, console.log involving formatting with the backtick notation doesn't work as I anticipated either: console.log(\{"abc": 123}`), still prints [object Object]`.
It might not be in scope for this PR, but I wanted to double-check with you to make sure these points don't go unnoticed 👀 🙇🏻

Here's a little test I wrote locally to experiment with it

export default function() {
  let emptyObjectBody = JSON.parse(`{}`);
  console.log(`Want: ${JSON.stringify(emptyObjectBody)}`);
  // console.log(`Got: ${emptyObjectBody}`);
  console.log(emptyObjectBody);

  let objectBody = JSON.parse(`{ "abc": 123, "easy as": "do re mi" }`);
  console.log(`Want: ${JSON.stringify(objectBody)}`);
  // console.log(`Got: ${objectBody}`);
  console.log(objectBody);

  let emptyArrayBody = JSON.parse(`[]`);
  console.log(`Want: ${JSON.stringify(emptyArrayBody)}`);
  // console.log(`Got: ${emptyArrayBody}`);
  console.log(emptyArrayBody);

  let arrayBody = JSON.parse(`[1, 2, 3]`);
  console.log(`Want: ${JSON.stringify(arrayBody)}`);
  // console.log(`Got: ${arrayBody}`);
  console.log(arrayBody);

  let mixedArrayBody = JSON.parse(`["abc", 123, {"foo": "bar"}, [1, 2, 3]]`);
  console.log(`Want: ${JSON.stringify(mixedArrayBody)}`);
  // console.log(`Got: ${mixedArrayBody}`);
  console.log(mixedArrayBody);
}

outputing this:

INFO[0000] Want: {}                                      source=console
INFO[0000] {}                                            source=console
INFO[0000] Want: {"abc":123,"easy as":"do re mi"}        source=console
INFO[0000] {"abc":123,"easy as":"do re mi"}              source=console
INFO[0000] Want: []                                      source=console
INFO[0000]                                               source=console
INFO[0000] Want: [1,2,3]                                 source=console
INFO[0000] 1,2,3                                         source=console
INFO[0000] Want: ["abc",123,{"foo":"bar"},[1,2,3]]       source=console
INFO[0000] abc,123,[object Object],1,2,3                 source=console

As a result, I would probably add tests cases covering these scenarios 🙇🏻 What do you think?

[codebien]

I applied some changes, @oleiade you're cases should be supported now.

I dropped the msg argument, it didn't seem necessary, let me know if you see a case to maintain it.

msg goja.Value, args ...goja.Value)

@codebien does this still happen with your code #644 (comment)

@mstoykov Do you mean the case of a circular object printed as [object Object]? JSON.stringify doesn't support that case. In the case of browsers and runtimes the console seems to have a dedicated spec for formatting the outputs.

[olegbespalov]

👍 LGTM left only one non-blocking comment

[oleiade]

🎉 👍🏻 🌮

[mstoykov]

LGTM.

Can you please explain how this is breaking change in the PR description. As well as point out how to get the previously reported values when possible.

[codebien]

@mstoykov @oleiade @olegbespalov I updated the description with changes and added a check in case of an empty argument list (e.g console.log()).

[oleiade]

👍🏻

[olegbespalov]

👍

[mstoykov]

It likely should just log an empty string (?) this is what firefox does and IMO will be less confusing 🤔

[codebien]

The output after the latest change

---script.js
export default function () {
	console.log()
	console.error()
	console.log("")
	console.log("the last one")
}

---output
INFO[0000]                                               source=console
ERRO[0000]                                               source=console
INFO[0000]                                               source=console
INFO[0000] the last one                                  source=console

[olegbespalov]

💪