Make "Unreachable code detected" compilation warning instead of error in TypeScript?

Question

In Typescript, when there is unreachable code, the compiler generates by default error:

error TS7027: Unreachable code detected.

I can avoid it by using compiler option allowUnreachableCode to true but can I change it somehow to warning?

I would still prefer to know about unreachable code. During development and debugging I sometimes use if (false) to temporarily remove some functionality, which is better than commenting the code out especially when the code itself contains comments.

In C#, unreachable code generates warning (which I can treat as error by other option), which seems to me better way to handle it.

Answer 1

In the particular case of temporarily removing functionality (which I think is the main case where one would want to have unreachable code), writing

if( <any>false ) {
  // unused code goes here
}

will prevent the TypeScript compiler from complaining, and give the runtime ECMAScript implementation a pretty good chance of optimizing the code away.

Alternatively,

if( 0 ) {
  // unused code goes here
}

will be accepted by the TypeScript language, but will still trigger an "unexpected constant condition" warning from tslint.