Typescript 3.3.1 wrongly considers object as 'Possibly 'undefined''

[vladimir-djokic]

TypeScript Version: 3.3.1

Issue: Even if the code is explicitly checking against variable not being undefined the compiler is complaining about Object is possibly 'undefined'. ts(2532) Strict checking is turned on with "strict": true.

[j-oliveras]

Duplicated/related to #9998.

Basically, typescript don't know if the predicate is called synchronously or not.

[vladimir-djokic]

Are you talking about find -> predicate function or the outer function of this code? Can you explain why this code compiles:

if (objectToMoveParentPathComponent !== undefined) {

    const c = objectToMoveParentPathComponent;

    const objectToMoveParent = objectToMoveResult.parents.find(
        p => p.parentObjectId === c.objectId // No error
    );

    // ...

}

[j-oliveras]

The predicate.

This code compiles because you created a local const variable c that is know to be defined. This is the workaround to this issue.

[typescript-bot]

This issue has been marked 'Working as Intended' and has seen no recent activity. It has been automatically closed for house-keeping purposes.