False positives on types imported with `import type`

It’s possible that this is an issue with ts-morph, but wanted to report this here. The new import type syntax introduced in TypeScript 3.8 appears to be resulting in false positives. Here’s an example (applying this patch on this repo @ https://github.com/nadeesha/ts-prune/commit/e879ac6e4d29e64fea872205a8d7c37e19256b22):

diff --git a/src/analyzer.ts b/src/analyzer.ts
index d767698..726f3ba 100644
--- a/src/analyzer.ts
+++ b/src/analyzer.ts
@@ -8,6 +8,7 @@ import {
 } from "ts-morph";
 import { isDefinitelyUsedImport } from "./util/isDefinitelyUsedImport";
 import { getModuleSourceFile } from "./util/getModuleSourceFile";
+import type { SomeType } from "./presenter";
 
 type OnResultType = (result: IAnalysedResult) => void;
 
@@ -22,7 +23,7 @@ export interface IAnalysedResult {
   symbols: Array<string>;
 }
 
-function handleExportDeclaration(node: SourceFileReferencingNodes) {
+function handleExportDeclaration(node: SourceFileReferencingNodes, _someParam?: SomeType) {
   return (node as ExportDeclaration).getNamedExports().map(n => n.getName());
 }
 
diff --git a/src/presenter.ts b/src/presenter.ts
index dcf1320..2115e1e 100644
--- a/src/presenter.ts
+++ b/src/presenter.ts
@@ -15,3 +15,5 @@ export const present = (state: State) => {
 
   return [].concat.apply([], unused2D) as Array<IAnalysedResult>;
 };
+
+export type SomeType = any;

This results in:

 ➜  ts-prune git:(master) ✗ ts-prune
SomeType @ ./src/presenter.ts

[nadeesha]

I couldn’t reproduce this is node 12 btw. Maybe something else is at play here. Anyways, thanks for reporting!

[JustFly1984]

@nadeesha import type is supported by @babel/core 6.9.0 and newer current version is 7.1.1