JavaScript proxy in additional context

Is it possible for additionalJsContext to capture a generic getter or setter from a proxy?

I’m providing:

const additionalJsContext = new Proxy({}, {
  set(obj, prop, value) {
    debug('set', {prop, value})
    obj[prop] = value
    return true
  },

  get(obj, prop) {
    const value = obj[prop]
    debug('get', {prop, value})
    return value === undefined ? null : value
  }
})

Then merge is used in this example [ref]:

  const sandbox: { [ind: string]: any } = merge(
    ctx.jsSandbox || {},
    {
      __code__: code,
      __result__: undefined,
    },
    data,
    ctx.options.additionalJsContext
  );

The generic “get” and “set” are not being merged into the sandbox object. If I put static properties in the 1st argument to Proxy it works or if I test my proxy alone additionalJsContext.anyprop === null it works. I’m not concerned about Proxy immutability, I can handle that with the set.

I’m have asked on the timm project too: https://github.com/guigrpa/timm/issues/52

This may be better handled here. Looks like using data instead will not help either. I’m also after the async support in additionalJsContext. Also, if you have a suggestion I don’t mind forking making changes and testing. I anticipate that I’m going to need to do this anyways.

[mathe42]

Just looked at the timm code and a work around should be:

const additionalJsContext = {
  key: new Proxy({}, {
    set(obj, prop, value) {
      debug('set', {prop, value})
      obj[prop] = value
      return true
    },
  
    get(obj, prop) {
      const value = obj[prop]
      debug('get', {prop, value})
      return value === undefined ? null : value
    }
  })
}

Where the key is not present in data. (and is not code nor result)

[edit] Sorry I just got what you want…

[jcalfee]

I tested v.__isProxy !== undefined ref and it works when I replace the two v instanceof Proxy checks . It errors err: Error: TypeError: eval is not a function. Probably this line: https://github.com/guigrpa/docx-templates/blob/28496607960efab8619ca006256d1d50fe5c0c7e/src/jsSandbox.ts#L49