2 files changed, 45 insertions, 12 deletions
diff --git a/std/node/_fs/_fs_close.ts b/std/node/_fs/_fs_close.ts
index 469bdc77b..cdd815ad9 100644
--- a/std/node/_fs/_fs_close.ts
+++ b/std/node/_fs/_fs_close.ts
@@ -3,20 +3,14 @@
 import { CallbackWithError } from "./_fs_common.ts";
 
 export function close(fd: number, callback: CallbackWithError): void {
-  new Promise((resolve, reject) => {
+  queueMicrotask(() => {
     try {
       Deno.close(fd);
-      resolve();
+      callback(null);
     } catch (err) {
-      reject(err);
-    }
-  })
-    .then(() => {
-      callback();
-    })
-    .catch((err) => {
       callback(err);
-    });
+    }
+  });
 }
 
 export function closeSync(fd: number): void {
diff --git a/std/node/_fs/_fs_close_test.ts b/std/node/_fs/_fs_close_test.ts
index 8bcd662c9..1ea324cb4 100644
--- a/std/node/_fs/_fs_close_test.ts
+++ b/std/node/_fs/_fs_close_test.ts
@@ -1,6 +1,6 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 const { test } = Deno;
-import { fail, assert } from "../../testing/asserts.ts";
+import { fail, assert, assertThrows } from "../../testing/asserts.ts";
 import { close, closeSync } from "./_fs_close.ts";
 
 test({
@@ -12,7 +12,7 @@ test({
     assert(Deno.resources()[file.rid]);
     await new Promise((resolve, reject) => {
       close(file.rid, (err) => {
-        if (err) reject();
+        if (err !== null) reject();
         else resolve();
       });
     })
@@ -29,6 +29,38 @@ test({
 });
 
 test({
+  name: "ASYNC: Invalid fd",
+  async fn() {
+    await new Promise((resolve, reject) => {
+      close(-1, (err) => {
+        if (err !== null) return resolve();
+        reject();
+      });
+    });
+  },
+});
+
+test({
+  name: "close callback should be asynchronous",
+  async fn() {
+    const tempFile: string = Deno.makeTempFileSync();
+    const file: Deno.File = Deno.openSync(tempFile);
+
+    let foo: string;
+    const promise = new Promise((resolve) => {
+      close(file.rid, () => {
+        assert(foo === "bar");
+        resolve();
+      });
+      foo = "bar";
+    });
+
+    await promise;
+    Deno.removeSync(tempFile);
+  },
+});
+
+test({
   name: "SYNC: File is closed",
   fn() {
     const tempFile: string = Deno.makeTempFileSync();
@@ -40,3 +72,10 @@ test({
     Deno.removeSync(tempFile);
   },
 });
+
+test({
+  name: "SYNC: Invalid fd",
+  fn() {
+    assertThrows(() => closeSync(-1));
+  },
+});