compiler error

[dulmandakh]

TypeScript Version: 2.7.0-dev.20171027

Code

const HTTP_PORT = (process.env && process.env.HTTP_PORT) ? parseInt(process.env.HTTP_PORT) : 3000;

or

const HTTP_PORT = (process.env && typeof process.env.HTTP_PORT === 'string') ? parseInt(process.env.HTTP_PORT) : 3000;

Expected behavior:
There shouldn't be a compile error

Actual behavior:
error TS2345: Argument of type 'string | undefined' is not assignable to parameter of type 'string'.
Type 'undefined' is not assignable to type 'string'.

[aluanhaddad]

This is a duplicate of #17960

[typescript-bot]

Automatically closing this issue for housekeeping purposes. The issue labels indicate that it is unactionable at the moment or has already been addressed.