check lazily

jestjs · Jan 2, 2024 · 7df45c8 · 7df45c8
1 parent 4633880
commit 7df45c8
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/packages/jest-haste-map/src/index.ts b/packages/jest-haste-map/src/index.ts
@@ -113,7 +113,7 @@ type Watcher = {
 
 type HasteWorker = typeof import('./worker');
 
-const isWatchmanInstalledPromise = isWatchmanInstalled();
+let isWatchmanInstalledPromise: Promise<boolean> | undefined;
 
 export const ModuleMap = HasteModuleMap as {
   create: (rootPath: string) => IModuleMap;
@@ -1109,6 +1109,9 @@ class HasteMap extends EventEmitter implements IHasteMap {
     if (!this._options.useWatchman) {
       return false;
     }
+    if (!isWatchmanInstalledPromise) {
+      isWatchmanInstalledPromise = isWatchmanInstalled();
+    }
     return isWatchmanInstalledPromise;
   }