From 36588a2c00cbd8ba13645554d6ee2b55eff58866 Mon Sep 17 00:00:00 2001
From: Keita Akutsu <kakts.git@gmail.com>
Date: Fri, 8 Jun 2018 01:30:58 +0900
Subject: [PATCH 1/2] test: add some test cases for validateOffsetLengthWrite.

---
 .../test-fs-util-validateoffsetlengthwrite.js | 56 +++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 test/parallel/test-fs-util-validateoffsetlengthwrite.js

diff --git a/test/parallel/test-fs-util-validateoffsetlengthwrite.js b/test/parallel/test-fs-util-validateoffsetlengthwrite.js
new file mode 100644
index 00000000000000..1df31f6dd8fe18
--- /dev/null
+++ b/test/parallel/test-fs-util-validateoffsetlengthwrite.js
@@ -0,0 +1,56 @@
+// Flags: --expose-internals
+
+'use strict';
+
+const common = require('../common');
+
+const { validateOffsetLengthWrite } = require('internal/fs/utils');
+const { kMaxLength } = require('buffer');
+
+// RangeError when offset > byteLength
+{
+  const offset = 100;
+  const length = 100;
+  const byteLength = 50;
+  common.expectsError(
+    () => validateOffsetLengthWrite(offset, length, byteLength),
+    {
+      code: 'ERR_OUT_OF_RANGE',
+      type: RangeError,
+      message: 'The value of "offset" is out of range. ' +
+               `It must be <= ${byteLength}. Received ${offset}`
+    }
+  );
+}
+
+// RangeError when byteLength > kMaxLength, and length > kMaxLength - offset .
+{
+  const offset = kMaxLength;
+  const length = 100;
+  const byteLength = kMaxLength + 1;
+  common.expectsError(
+    () => validateOffsetLengthWrite(offset, length, byteLength),
+    {
+      code: 'ERR_OUT_OF_RANGE',
+      type: RangeError,
+      message: 'The value of "length" is out of range. ' +
+               `It must be <= ${kMaxLength - offset}. Received ${length}`
+    }
+  );
+}
+
+// RangeError when byteLength < kMaxLength, and length > byteLength - offset .
+{
+  const offset = kMaxLength - 150;
+  const length = 200;
+  const byteLength = kMaxLength - 100;
+  common.expectsError(
+    () => validateOffsetLengthWrite(offset, length, byteLength),
+    {
+      code: 'ERR_OUT_OF_RANGE',
+      type: RangeError,
+      message: 'The value of "length" is out of range. ' +
+               `It must be <= ${byteLength - offset}. Received ${length}`
+    }
+  );
+}

From 593cbadb8d0f419379c5ae58588f40b8e4eb3f80 Mon Sep 17 00:00:00 2001
From: Keita Akutsu <kakts.git@gmail.com>
Date: Mon, 11 Jun 2018 22:25:36 +0900
Subject: [PATCH 2/2] test: delete a white space.

---
 test/parallel/test-fs-util-validateoffsetlengthwrite.js | 1 -
 1 file changed, 1 deletion(-)

diff --git a/test/parallel/test-fs-util-validateoffsetlengthwrite.js b/test/parallel/test-fs-util-validateoffsetlengthwrite.js
index 1df31f6dd8fe18..9aca956bd505bf 100644
--- a/test/parallel/test-fs-util-validateoffsetlengthwrite.js
+++ b/test/parallel/test-fs-util-validateoffsetlengthwrite.js
@@ -1,5 +1,4 @@
 // Flags: --expose-internals
-
 'use strict';
 
 const common = require('../common');