CODEWITHSUNDEEP
node.js
David Gatti
David Gatti

Reputation: 3701

JSON.stringify() a string which is actual NodeJS code

I'm working with the Readline module in NodeJS and would like to parse the content of what the user wrote as code. Meaning if someone writes:

{
    name: "David",
    age: 34
}

I should be able to JSON.stringify(content) and get:

{
    "name": "David",
    "age": "34"
}

How can I convert a string in to actual code, so it can be interpreted as a JavaScript object, thus be converted in to JSON using JSON.stringify()?

Upvotes: 0

Views: 2431

Answers (2)

David Gatti
David Gatti

Reputation: 3701

The trick to make this work is to use the VM module in a undocumented way as seen below. 

let vm = require('vm');

let script = new vm.Script('x = ' + full_content);

let sandbox = script.runInThisContext();

converted = JSON.stringify(sandbox);

Basically you have to create a variable that will hold your string (JavaScript), which will be then converted in to proper JavaScript code thanks to .runInThisContext().

In this case the x variable will "disappear" and you don't have to think about that. But if you were to follow the NodeJS documentation example, and use .runInNewContext() then the x variable wouldn't go away, a you would have your object (in my case at least) assigned to the x variable.

Hope this helps :)

Upvotes: 1

Jim Clouse
Jim Clouse

Reputation: 8990

It's not entirely clear what you're asking, but, would JSON.parse() help you here? You'll want to wrap it in a try catch in case the input is not valid JSON.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse

Upvotes: 1

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