Unexpected prop-missing error when destructuring an array

[Robloche]

Try these lines:

const arr = [{foo: 42}, {foo: 17}];
const index = 1;
const {[index]: {foo}} = arr;

As you can see here, no error is reported until v0.184 but v0.185+ raises a prop-missing error.

It is worthy to note that replacing index by a number works in v0.185:

const arr = [{foo: 42}, {foo: 17}];
const {[1]: {foo}} = arr;

[Robloche]

The same issue arises when destructuring objects:

const obj = {foo: {bar: 42}};
const key = 'foo';
const {[key]: {bar}} = obj;

Try it here.

[panagosg7]

Thanks for the report and the repros @Robloche !

This surfaced as an issue in 0.185 since we turned on inference_mode=constrain_writes by default.

I have identified the root cause and I am preparing a fix. Hopefully, it will be included in 0.186.