Rename Symbol on variable sourcing a return destructured object leads to compiler error

[mjbvz]

From @greyepoxy on October 13, 2017 22:33

• VSCode Version: Code 1.17.1 (1e9d36539b0ae51ac09b9d4673ebea4e447e5353, 2017-10-10T14:24:50.851Z)
• OS Version: Windows_NT x64 10.0.14393
• Typescript: 2.5.3

---

Steps to Reproduce:

1. I have the following typescript code

interface Result {
    a: number;
}

export function doThing(): Result {
    const a = 5 + 10;

    return {
        a
    };
}

2. Highlight a at its declaration in const a
3. Hit F2 and rename the symbol to b

Expected:

1. A symbol rename to not lead to a compiler error
2. Something like the following:

export function doThing(): Result {
    const b = 5 + 10;

    return {
        a: b
    };
}

Actual:

export function doThing(): Result {
    const b = 5 + 10;

    return {
        b // <-- this has the error below
    };
}

severity: 'Error'
message: 'Type '{ b: number; }' is not assignable to type 'Result'.
Object literal may only specify known properties, and 'b' does not exist in type 'Result'.'

Reproduces without extensions: Yes

Copied from original issue: microsoft/vscode#36252

[mjbvz]

Possibly another case of #15787

[mhegazy]

Also another case of #14039

[mjbvz]

The safe rename is now the default (a way to revert to the old, unsafe behavior was added by #29238)