Cannot define a module for a specific file extension in 2.4.1

[vekexasia]

TypeScript Version: 2.4.1
Code

// A *self-contained* demonstration of the problem follows...
declare module "*.vue" {
  import Vue from 'vue'
  export default typeof Vue
}

Expected behavior:
A file with the above content used to work when importing .vue files.
In 2.4.1 It looks like the file is not taken into account as every .vue file gets imported as "string"?
Actual behavior:
Everything seems to be imported as string?

[vekexasia]

That file is perfectly working in 2.3.4

[mhegazy]

The right hand side of an export default is an expression not a type. typeof Vue is just calling the regular JS typeof operator on the reference Vue; and that happens to be a string all the time..

This should have been an error to have an expression in an ambient context. the only possible value should be an identifier name. files #17991 to track it.

so for this definition, you need to change your declaration to be:

declare module "*.vue" {
    import Vue from 'vue'
    const _: typeof Vue;
    export default _;
}

[mhegazy]

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