JS Class expression with js-valued return type methods cause duplicated errors

[weswigham]

Found in #24247

TypeScript Version: 2.9.0-dev.201xxxxx

Search Terms:

Code

// @ts-check
var A = {};
A.B = {};
A.B.C = [
    {
        o: "no",
        y: 42
    }
];

A.Foo = class {
    /**
     * @returns {?A}
     */
    foo() {
        return A.B.C.find(x => !!x);
    }
}

Expected behavior:

Actual behavior:

(2 errors instead of 1 - one without elaboration)
In trying to edit this down further, I've found that removing the nested namespace on B seems to remove the bug, as does changing the return type of foo to not reference A, or changing from a class to an object literal for A.Foo - so it seems a great deal of things must be kept in place to reproduce this error.

[sandersn]

I can't get this to repro anymore, but the dupes are still in the chrome-devtools-frontend baselines. Looks like I might need to re-isolate this one.

[sandersn]

Here's a smaller repro:

var A = {};
A.B = class {
    /**
     * @return {any[]}
     */
    m() {
        return {};
    }
};

[sandersn]

Could be that we're double-checking methods here. Anything with elaborations gets double errors:

var A = {};
A.B = class {
    m() {
        /** @type {string[]} */
        var x = [];
        /** @type {number[]} */
        var y;
        y = x;
    }
};

From a quick debugging run-through, it looks like deferredNodes gets the same node pushed onto it twice.