how to delete a property from an object in Typescript without the operand of a 'delete' operator must be optional error?

Question

I have tried to read how to delete a property from an object in here: How do I remove a property from a JavaScript object?

it should use delete, I try it like this

const eventData = {...myEvent}; // myEvent is an instance of my `Event` class
delete eventData.coordinate; // I have error in here

but I have error like this

The operand of a 'delete' operator must be optional.ts(2790)

and then I read this : Typescript does not infer about delete operator and spread operator?

it seems to remove that error is by changing my tsconfig.json file using

{
  "compilerOptions": {
    ...
     "strictNullChecks": false, 
    }
    ...
}

but if I implement this, I will no longer have null checking

so how to delete a property from an object in Typescript without the operand of a 'delete' operator must be optional error?

Answer 1

Typescript warns you about breaking the contract (the object won't have the required property anymore). One of the possible ways would be omitting the property when you cloning the object:

const myEvent = {
    coordinate: 1,
    foo: 'foo',
    bar: true
};

const { coordinate, ...eventData } = myEvent;
// eventData is of type { foo: string; bar: boolean; }

Playground

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Operands for delete must be optional. When using the delete operator in strictNullChecks, the operand must be any, unknown, never, or be optional (in that it contains undefined in the type). Otherwise, use of the delete operator is an error.

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