Add error resiliency to waitForPath

Signed-off-by: Sebastian Malton <sebastian@malton.name>

src/common/utils/wait-for-path.ts

@@ -3,30 +3,53 @@
  * Licensed under MIT License. See LICENSE in root directory for more information.
  */
 
-import { watch } from "chokidar";
+import { FSWatcher } from "chokidar";
 import path from "path";
 
 /**
  * Wait for `filePath` and all parent directories to exist.
- * @param filePath The file path to wait until it exists
+ * @param pathname The file path to wait until it exists
+ *
+ * NOTE: There is technically a race condition in this function of the form
+ * "time-of-check to time-of-use" because we have to wait for each parent
+ * directory to exist first.
  */
-export async function waitForPath(filePath: string): Promise<void> {
-  const dirOfPath = path.dirname(filePath);
+export async function waitForPath(pathname: string): Promise<void> {
+  const dirOfPath = path.dirname(pathname);
 
-  if (dirOfPath === filePath) {
+  if (dirOfPath === pathname) {
     // The root of this filesystem, assume it exists
     return;
   } else {
     await waitForPath(dirOfPath);
   }
 
-  return new Promise(resolve => {
-    watch(dirOfPath, {
+  return new Promise((resolve, reject) => {
+    const watcher = new FSWatcher({
       depth: 0,
-    }).on("all", (event, path) => {
-      if ((event === "add" || event === "addDir") && path === filePath) {
-        resolve();
-      }
+      disableGlobbing: true,
     });
+    const onAddOrAddDir = (filePath: string) => {
+      if (filePath === pathname) {
+        watcher.unwatch(dirOfPath);
+        watcher
+          .close()
+          .then(() => resolve())
+          .catch(reject);
+      }
+    };
+    const onError = (error: any) => {
+      watcher.unwatch(dirOfPath);
+      watcher
+        .close()
+        .then(() => reject(error))
+        .catch(() => reject(error));
+    };
+
+    watcher
+      .on("add", onAddOrAddDir)
+      .on("addDir", onAddOrAddDir)
+      .on("error", onError)
+      .add(dirOfPath);
   });
 }