Allows you to configure functions not to pass arguments when they can be undefined

[guaijie]

🔎 Search Terms

"undefined", "void", "optional", "no arguments", "rules"

🕗 Version & Regression Information

• This is the behavior in every version I tried, and I reviewed the FAQ for entries about typescript

⏯ Playground Link

No response

💻 Code

const fn1= (param: undefined | number) => {}
const fn2 = (param: undefined | number) => {}

🙁 Actual behavior

fn1(undefined) // success
fn1() // fail
fn2(undefined) //success
fn2() // success

🙂 Expected behavior

fn1(undefined) // success
fn1() // success 
fn2(undefined) //success
fn2() // success

Additional information about the issue

No response

[fatcerberus]

This is what optional parameters are for

const fn1 = (param?: number) => {};
fn1(undefined);  // works
fn1();           // also works

[jcalz]

Duplicate of #12400

[typescript-bot]

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