Suggestion diagnostics contain unused variables from some other file and dont make sense at all

[sheetalkamat]

TypeScript Version: 2.9.0-dev.201xxxxx

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Code
In folder say temp:

npm i sass.js

create index.js here with contents

//@ts-check
require('sass.js')

code .
open index.js
Check the suggestion diagnostics

Expected behavior:
[ts] File is a CommonJS module; it may be converted to an ES6 module.

Actual behavior:
[ts] File is a CommonJS module; it may be converted to an ES6 module.
[ts] 'dynCall' is declared but its value is never read.
[ts] 'addLeadingSlash' is declared but its value is never read.
[ts] 'stripTrailingSlash' is declared but its value is never read.
[ts] 'SASSJS_RELATIVE_PATH' is declared but its value is never read.
[ts] 'funcWrappers' is declared but its value is never read.
[ts] 'EXITSTATUS' is declared but its value is never read.