Instance of descendant class is shown as instance of base class in component's props

[jeron-diovis]

It's looks very similar to #308, but about passing some class instance to component's props. Not related to React.Component at all.

In short, I'm doing following:

class A { ...whatever... }

class B extends A {
  constructor() {
    super()
    this.some = {}
  }

  get foo() {
    return this.some.value
  }
}

<MyComponent the_instance={new B()} />

Then, devtools shows me correct info:

When accessing in console $r.props.the_instance.foo, it also works normal:

BUT when expanding the_instance prop in devtool's sidebar, smth strange happens:

Now it's an instance of not B but A, and obviously crashes because can't read property of undefined.

Not fatal, but annoying thing, which complicates debugging.

---

Don't know how to create live demo, because have no idea how to connect react-devtools to React inside iframe.

If it can help, my .babelrc:

{
  "presets": [
    [ "env", {
      "targets": {
        "browsers": [
          "last 2 versions"
        ]
      },
      "useBuiltIns": true
    }],

    "react"
  ],

  "plugins": [
    "syntax-dynamic-import",
    "transform-object-rest-spread",

    [ "transform-runtime", { "polyfill": false } ],

    [ "transform-builtin-extend", {
      "globals": [ "Error" ]
    }],

    "transform-decorators-legacy",
    "transform-class-properties",
    "transform-async-generator-functions"
  ],

  "env": {
    "development": {
      "plugins": [
        "transform-react-jsx-source"
      ]
    }
  }
}

[bvaughn]

Looks like a duplicate of #893 and #976

Repro case: https://codesandbox.io/s/887ql3mrv8