Type inference corner case in combination of object spread with destructuring

TypeScript Version: 2.2.0-dev.20161127

Code

declare var keyPrototype: any
declare function getKeyData(): Promise<{ key: any }>

async function getKey () {
  const { key } = {
    key: {
      ...keyPrototype
    },
    ...await getKeyData()
  }
  return key
}

Expected behavior:

Code to typecheck. The resulting key const should be a shallow copy of keyPrototype, with certain keys overridden by the result of getKeyData.

Actual behavior:

Error on the key declaration inside const { key }: "Initializer provides no value for this binding element and the binding element has no default value", despite the RHS being guaranteed to always have a key key.

Remove special symbol for untyped modules

This is probably a duplicate. In TSX file, this works fine:

const { children, ...rest} = this.props;  // OK

When I try to do this, I get the same error you're seeing:

const { children, ...rest} = {    // Error
    ...this.props,
    someProp: forcedValue,
}

Works if I supply a default value, but I don't think it should require one:

const { children = null, ...rest} = {
    ...this.props,
    prop: forcedValue,
}

I'm having this issue as well.

This appears to be fixed in version 2.7.0-dev.20171230. Perhaps by #19513? Recommend for closing.

Yep, original repro works now.

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Type inference corner case in combination of object spread with destructuring #12532

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Type inference corner case in combination of object spread with destructuring #12532

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DarylCantrell commented on Jun 12, 2017

robyoder commented on Oct 5, 2017

robyoder commented on Dec 31, 2017

sandersn commented on Jan 2, 2018

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