Improve support of non-relative imports in projects with a baseUrl

[josh-]

Thanks for all your work on this great project @timocov.

I noticed a small issue when using non-relative imports in TypeScript projects with a baseUrl configured. It appears that resolveModuleFileName treats all modules that isn't prefixed with a . as an external node_module, which causes needStripImportFromImportTypeNode to not strip these generated import() statements.

For example, prior to this change, the result of the import-from-non-relative-path-inferred-type test would be:

export interface MyType {
	field: string;
}
export declare function test(): import("field/type").MyType;

export {};

The import() here is unnecessary since MyType is already defined in the declaration file, and should be stripped.

This PR currently resolves the issue described above by, when a baseUrl is defined, checking whether a module exists relative to that baseUrl, before falling back to node_modules/${moduleName}/ if the module does not exist at that path.

[timocov]

@josh- It seems that it is turning into something bigger than just one simple change (in my case it is more than 300 lines already and I still need to make some changes). I'll take it over and finish the fix. Thanks for you contribution! Let's keep this PR open for now (I'll use your commits and make changes on top of).

[josh-]

@josh- It seems that it is turning into something bigger than just one simple change (in my case it is more than 300 lines already and I still need to make some changes). I'll take it over and finish the fix. Thanks for you contribution! Let's keep this PR open for now (I'll use your commits and make changes on top of).

No worries at all, that sounds great!

[timocov]

The issue will be fixed in #224

[timocov]

The fix has been released in v7.0.0.