Incorrect type inference of 'unknown'

[rav2040]

TypeScript Version: 3.8.3

Search Terms:
unknown, null, incorrect, conditional, type inference

Expected behavior:
There should not be an error when using a conditional to correctly narrow down an unknown variable to a variable of type object.

Actual behavior:
Given a variable foo of type unknown, it is correctly inferred to be of type object when the following are both true:

1. typeof foo === 'object'
2. foo !== null

However, when the order is swapped, the type of foo is incorrectly inferred to be of type object | null.

Related Issues:
Could not find related issues.

Code

const foo = {} as unknown;

let bar: object;

if (typeof foo === 'object' && foo !== null) {
    bar = foo; // type of 'foo' is correctly inferred to be 'object'
}

if (foo !== null && typeof foo === 'object') {
    bar = foo; // type of 'foo' is incorrectly inferred to be 'object | null'
}

Output

"use strict";
const foo = {};
let bar;
if (typeof foo === 'object' && foo !== null) {
    bar = foo; // type of 'foo' is correctly inferred to be 'object'
}
if (foo !== null && typeof foo === 'object') {
    bar = foo; // type of 'foo' is incorrectly inferred to be 'object | null'
}

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

[MartinJohns]

Duplicate of #37658.

[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.