TypeScript: __dirname value?

Question

My folder structure is like this:

app
└─ tsFolder
   └─ XX.ts

Code in XX.ts file:

var __dirname: string;
console.log("__dirname: " + __dirname); // the output is undefined.

I have tried it: by comment out the code var __dirname: string;, the value of __dirname is: ...../app insead of pointing to the current folder like ...../app/tsFolder.

Can anyone explain it?

Answer 1

Just run

npm install --save-dev @types/node

And if that doesn't work on its own, add

"types": ["node"]

to your tsconfig.json's compilerOptions field.

Answer 2

I assume you refer to NodeJS global variable __dirname.

If it points to the ..../app it means that your XX.ts is compiled to the ..../app folder. And when the resulting js file is run: __dirname points to its (js file) location.

And of course, you should not declare new var __dirname.

Instead, either use NodeJS typings or just declare it manually like this:

declare var __dirname;