CODEWITHSUNDEEP
node.jstypescript
Motti
Motti

Reputation: 114805

Why is a global `name` variable declared in typescript and can I avoid using it?

A friend refactored some code and moved the definition of a variable called name from the function's top-level scope into a then's body. This variable was used in a subsequent then which caused a ReferenceError since name was not in scope.

We couldn't understand how the code passed compilation until we saw that typescript/lib.d.ts has the following deceleration:

declare const name: never;

Long story short, I have two questions.

  1. Why is name (as well as length and many other globals) added by default to typescript?
  2. From the surrounding code this seems meant for projects intended to run in a browser, we're a node.js project. Can we opt out from having these declarations added for us?

Upvotes: 9

Views: 1959

Answers (1)

Sebastian Sebald
Sebastian Sebald

Reputation: 16876

This seems to be a very old browser behaviour. Referring to the MDN both name and length are properties of the window object.

In order to get rid of all the DOM-specific declarations, you can set the lib property in your tsconfig accordingly. You cann see all options on this page. Take a look at the --lib flag.

An option to tell TypeScript your code runs on Node.JS would be nice. But it seems not yet implemented: https://github.com/Microsoft/TypeScript/issues/9466

Upvotes: 12

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