From 9ff2b8f0f65ff05558b03bf00811c2c96b7b099b Mon Sep 17 00:00:00 2001
From: Morgan Zolob <mzolob@gmail.com>
Date: Tue, 20 May 2025 17:34:56 -0700
Subject: [PATCH] fix: handle undefined paths in getModifiedTime

When building projects in `tsc` build mode (with `typescript.build` set
to `true`), some paths passed to `getModifiedTime` will be `undefined`.
Previously, this would cause an error and prevent type-checking (see
https://github.com/TypeStrong/fork-ts-checker-webpack-plugin/issues/855).
With these changes, the modified time will just be returned as
`undefined` in such cases, which allows type checking to complete
successfully.
---
 src/typescript/worker/lib/system.ts | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/typescript/worker/lib/system.ts b/src/typescript/worker/lib/system.ts
index 65f85122..8138fd12 100644
--- a/src/typescript/worker/lib/system.ts
+++ b/src/typescript/worker/lib/system.ts
@@ -114,6 +114,10 @@ export const system: ControlledTypeScriptSystem = {
       .map((dirent) => dirent.name);
   },
   getModifiedTime(path: string): Date | undefined {
+    if (typeof path !== "string") {
+      return undefined;
+    }
+
     const stats = getReadFileSystem(path).readStats(path);
 
     if (stats) {