ts.transpileModule does not return diagnostics

[alex-kinokon]

TypeScript Version: 2.4.2

Code

import * as ts from 'typescript';

const module = ts.transpileModule('const a: string = 2; a = 0;', {
  reportDiagnostics: true,
});
console.log(module.diagnostics);

Expected behavior:
Reports [ts] Type '2' is not assignable to type 'string'.

Actual behavior:
Diagnostics is an empty array [].

[aluanhaddad]

From what I understand, that is precisely the point of the transpile module API. It exposes TypeScript's ability to transform ESNext code intro various targets while removing TypeScript specific syntax without typechecking. This is useful for many tool chains that wish to perform typechecking and transpilation separately.

[kitsonk]

Duplicate of #4864