Use local error instead of global for stale locks.

Author: RubenVerborgh

lib/lock.js

@@ -3,25 +3,29 @@ const { lock } = require('proper-lockfile')
 const staleSeconds = 30
 
 // Obtains a lock on the path, and maintains it until the callback finishes
-async function withLock (path, options = {}, callback = options) {
-  // Obtain the lock
-  const releaseLock = await lock(path, {
-    retries: 10,
-    update: 1000,
-    stale: staleSeconds * 1000,
-    realpath: !!options.mustExist,
-    onCompromised: () => {
-      throw new Error(`The file at ${path} was not updated within ${staleSeconds}s.`)
+function withLock (path, options = {}, callback = options) {
+  return new Promise(async (resolve, reject) => {
+    let releaseLock, result
+    try {
+      // Obtain the lock
+      releaseLock = await lock(path, {
+        retries: 10,
+        update: 1000,
+        stale: staleSeconds * 1000,
+        realpath: !!options.mustExist,
+        onCompromised: () =>
+          reject(new Error(`The file at ${path} was not updated within ${staleSeconds}s.`))
+      })
+      // Hold on to the lock until the callback's returned promise resolves
+      result = await callback()
+    } catch (error) {
+      reject(error)
+    // Ensure the lock is always released
+    } finally {
+      await releaseLock()
     }
+    resolve(result)
   })
-
-  // Try executing the callback, waiting for its returned promise to resolve
-  try {
-    return await callback()
-  } finally {
-    // Ensure the lock is always released
-    releaseLock()
-  }
 }
 
 module.exports = withLock