Exception in checkIndexConstraintForProperty when handling assignment to property in constructor

[TysonAndre]

TypeScript Version: master branch as of today(may 9th) (a72a9aa)

Code

// (Using react version "15.4.2")
// This is a .js file, using --checkJS (and extra lines were cut out)
// A *self-contained* demonstration of the problem follows...
// 
define(function(require) {
    'use strict';

    const React = require('react');
    const { Component } = React;

    class Something extends Component {

        constructor(props) {
            super(props)

            this.state = { };  // This overrides a parent property - see https://facebook.github.io/react/docs/react-component.html#state
        }
    }

    return Something;
});

Command used (NOTE: there was no config file used here, just command line flags)

tsc --checkJs --noEmit --allowJs example.js

Expected behavior:
Does not crash
Actual behavior:
Crashes because of the assignment of {} to this.state (property of parent class Component)

TypeError: Cannot read property 'kind' of undefined
    at checkIndexConstraintForProperty (/usr/local/node/lib/node_modules/typescript/lib/tsc.js:36208:61)
    at /usr/local/node/lib/node_modules/typescript/lib/tsc.js:36173:21
    at Object.forEach (/usr/local/node/lib/node_modules/typescript/lib/tsc.js:288:30)
    at checkIndexConstraints (/usr/local/node/lib/node_modules/typescript/lib/tsc.js:36171:20)
    at checkClassLikeDeclaration (/usr/local/node/lib/node_modules/typescript/lib/tsc.js:36406:17)
    at checkClassDeclaration (/usr/local/node/lib/node_modules/typescript/lib/tsc.js:36324:13)
    at checkSourceElement (/usr/local/node/lib/node_modules/typescript/lib/tsc.js:37259:28)
    at Object.forEach (/usr/local/node/lib/node_modules/typescript/lib/tsc.js:288:30)
    at checkBlock (/usr/local/node/lib/node_modules/typescript/lib/tsc.js:35383:16)
    at checkSourceElement (/usr/local/node/lib/node_modules/typescript/lib/tsc.js:37222:28)

This was seen after the fix for #15616 was merged
This happens whether or not PR 15594 is merged (I think)

[RyanCavanaugh]

Looks extremely similar to #15525

[mhegazy]

indeed a duplicate. the fix should in tomorrows' typescript@next.

[TysonAndre]

It isn't a duplicate, this happened after the fix was merged.

See https://github.com/Microsoft/TypeScript/pull/15586/files#r115359347 for the line causing this error

It translates to the below:

                if (propDeclaration && (propDeclaration.name.kind === 144 || prop.parent === containingType.symbol)) {
                    errorNode = propDeclaration;
                }     
                else if (indexDeclaration) {
                    errorNode = indexDeclaration;
                }    

[sandersn]

I believe this class of bugs should be squashed completely with #15594, which prevents access to Declaration.name and adds a getNameOfDeclaration utility. It also introduces a new type, NamedDeclaration, for the declarations that always have a name.

[sandersn]

Fix is ready #15594

[ninja-]

is there any workaround for now?

[sandersn]

The workaround is not to use checkjs. I just merged the fix, so it should be in tomorrow's nightly (May 11)

[chris-codaio]

Any word on this will be released (presumably the release date of 2.3.3)?