Typescript 5.0.2 does not infer type correctly with React.isValidElement

[changwoolab]

Bug Report

import React from "react";

type B = {
  b1: string;
  b2: number;
};

export function type(input: React.ReactElement | string | B) {
  if (typeof input === "string") {
    return input;
  }

  if (React.isValidElement(input)) {
    return input;
  }

  return input.b1;
}

After running tsc in the console, I got this error.

But there was no error in VScode and type inference was working well

Also, there was no error with 4.9.4.

🔎 Search Terms

typescript 5.0, React, ReactElement, isValidElement, inference, deduce

🕗 Version & Regression Information

After upgrading to typescript 5.0.2 and running tsc in the console.

• This is a crash
• This changed between versions 4.9.4 and 5.0.2
• This is the behavior in every version I tried, and I reviewed the FAQ for entries about _________
• I was unable to test this on prior versions because _______

⏯ Playground Link

Playground link with relevant code

💻 Code

import React from "react";

type B = {
  b1: string;
  b2: number;
};

export function type(input: React.ReactElement | string | B) {
  if (typeof input === "string") {
    return input;
  }

  if (React.isValidElement(input)) {
    return input;
  }

  return input.b1;
}

🙁 Actual behavior

Type of input at the last line was B | ReactElement

🙂 Expected behavior

Type of input at the last line should be B

[MartinJohns]

This seems to be a duplicate of #53178.

[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.