the type error checking bug

[KenFront]

TypeScript Version: 3.9.2

**Expected behavior: the two checked results to update properties of object should be same.

**Actual behavior: there is a type error in way 2, but not in way 1.

Code

interface xxx {
    id: string;
    name: string;
    description?: string;
}

const test = (propName: keyof xxx) => {
    const o: xxx = {
        id: '1',
        name: '1',
        description: '1'
    }
    const o2: xxx = {
        id: '1',
        name: '1',
        description: '1'
    }
    // change property way 1
    const o3 = {
        ...o,
        [propName]: o2[propName]
    }

    // change property way 2
    o[propName] = o2[propName]
}

Output

"use strict";
const test = (propName) => {
    const o = {
        id: '1',
        name: '1',
        description: '1'
    };
    const o2 = {
        id: '1',
        name: '1',
        description: '1'
    };
    // change property way 1
    const o3 = Object.assign(Object.assign({}, o), { [propName]: o2[propName] });
    // change property way 2
    o[propName] = o2[propName];
};

Compiler Options

{
  "compilerOptions": {
    "noImplicitAny": true,
    "strictNullChecks": true,
    "strictFunctionTypes": true,
    "strictPropertyInitialization": true,
    "strictBindCallApply": true,
    "noImplicitThis": true,
    "noImplicitReturns": true,
    "alwaysStrict": true,
    "esModuleInterop": true,
    "declaration": true,
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true,
    "moduleResolution": 2,
    "target": "ES2017",
    "jsx": "React",
    "module": "ESNext"
  }
}

Playground Link: Provided

Description: I am not sure the result for both of them should be correct or not. I just think they should be same.

[jcalz]

Duplicate of #13948 and #27273

[typescript-bot]

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