const f2 = (args: {file: string, folder: string}) => { } f2({ file: '/tmp',
folder: 'foo.txt' }); // easier to see the error

TS Playground:
https://www.typescriptlang.org/play/index.html#src=const%20f1%20%3D%20(file%3A%20string%2C%20folder%3A%20string)%20%3D%3E%20%7B%20%7D%0D%0Af1('%2Ftmp'%2C%20'foo.txt')%3B%20%2F%2F%20spot%20the%20error%3F%0D%0A%0D%0Aconst%20f2%20%3D%20(args%3A%20%7Bfile%3A%20string%2C%20folder%3A%20string%7D)%20%3D%3E%20%7B%20%7D%0D%0Af2(%7B%0D%0A%20%20%20%20file%3A%20'%2Ftmp'%2C%0D%0A%20%20%20%20folder%3A%20'foo.txt'%0D%0A%7D)%3B%20%2F%2F%20easier%20to%20see%20the%20error

This is especially true when the function is defined elsewhere.