Check if file is not null when watching dir

src/cli/run.js

@@ -185,6 +185,9 @@ module.exports = function (argv) {
       // Since lowdb uses atomic writing, directory is watched instead of file
       const watchedDir = path.dirname(source)
       fs.watch(watchedDir, (event, file) => {
+        // https://github.com/typicode/json-server/issues/420
+        // file can be null
+        if (file) {
           const watchedFile = path.resolve(watchedDir, file)
           if (watchedFile === path.resolve(source)) {
             if (is.JSON(watchedFile)) {
@@ -202,18 +205,21 @@ module.exports = function (argv) {
               start()
             }
           }
+        }
       })
 
       // Watch routes
       if (argv.routes) {
         const watchedDir = path.dirname(argv.routes)
         fs.watch(watchedDir, (event, file) => {
+          if (file) {
             const watchedFile = path.resolve(watchedDir, file)
             if (watchedFile === path.resolve(argv.routes)) {
               console.log(chalk.gray(`  ${argv.routes} has changed, reloading...`))
               server && server.destroy()
               start()
             }
+          }
         })
       }
     }