From d453fac33b0769a12b8b926f0d77e1bbd834b397 Mon Sep 17 00:00:00 2001
From: James M Snell <jasnell@gmail.com>
Date: Sun, 26 Nov 2017 14:06:50 -0800
Subject: [PATCH] fs: move type checking for fs.ftruncate to js

PR-URL: https://github.com/nodejs/node/pull/17334
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Timothy Gu <timothygu99@gmail.com>
Reviewed-By: Jon Moss <me@jonathanmoss.me>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
---
 lib/fs.js                         |  8 ++--
 src/node_file.cc                  | 19 ++--------
 test/parallel/test-fs-truncate.js | 61 +++++++++++++++++++++++++++++++
 3 files changed, 68 insertions(+), 20 deletions(-)

diff --git a/lib/fs.js b/lib/fs.js
index 9d9ba706127..1a93d0acf2e 100644
--- a/lib/fs.js
+++ b/lib/fs.js
@@ -864,11 +864,11 @@ fs.ftruncate = function(fd, len, callback) {
   } else if (len === undefined) {
     len = 0;
   }
-  if (typeof fd !== 'number')
+  if (!Number.isInteger(fd))
     throw new errors.TypeError('ERR_INVALID_ARG_TYPE', 'fd', 'number');
   if (fd < 0 || fd > 0xFFFFFFFF)
     throw new errors.RangeError('ERR_OUT_OF_RANGE', 'fd');
-  if (typeof len !== 'number')
+  if (!Number.isInteger(len))
     throw new errors.TypeError('ERR_INVALID_ARG_TYPE', 'len', 'number');
   len = Math.max(0, len);
   const req = new FSReqWrap();
@@ -880,11 +880,11 @@ fs.ftruncateSync = function(fd, len) {
   if (len === undefined) {
     len = 0;
   }
-  if (typeof fd !== 'number')
+  if (!Number.isInteger(fd))
     throw new errors.TypeError('ERR_INVALID_ARG_TYPE', 'fd', 'number');
   if (fd < 0 || fd > 0xFFFFFFFF)
     throw new errors.RangeError('ERR_OUT_OF_RANGE', 'fd');
-  if (typeof len !== 'number')
+  if (!Number.isInteger(len))
     throw new errors.TypeError('ERR_INVALID_ARG_TYPE', 'len', 'number');
   len = Math.max(0, len);
   return binding.ftruncate(fd, len);
diff --git a/src/node_file.cc b/src/node_file.cc
index 13155bedb10..c330c95fa67 100644
--- a/src/node_file.cc
+++ b/src/node_file.cc
@@ -763,24 +763,11 @@ static void Rename(const FunctionCallbackInfo<Value>& args) {
 static void FTruncate(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  if (args.Length() < 2)
-    return TYPE_ERROR("fd and length are required");
-  if (!args[0]->IsInt32())
-    return TYPE_ERROR("fd must be a file descriptor");
+  CHECK(args[0]->IsInt32());
+  CHECK(args[1]->IsNumber());
 
   int fd = args[0]->Int32Value();
-
-  // FIXME(bnoordhuis) It's questionable to reject non-ints here but still
-  // allow implicit coercion from null or undefined to zero.  Probably best
-  // handled in lib/fs.js.
-  Local<Value> len_v(args[1]);
-  if (!len_v->IsUndefined() &&
-      !len_v->IsNull() &&
-      !IsInt64(len_v->NumberValue())) {
-    return env->ThrowTypeError("Not an integer");
-  }
-
-  const int64_t len = len_v->IntegerValue();
+  const int64_t len = args[1]->IntegerValue();
 
   if (args[2]->IsObject()) {
     ASYNC_CALL(ftruncate, args[2], UTF8, fd, len)
diff --git a/test/parallel/test-fs-truncate.js b/test/parallel/test-fs-truncate.js
index 4119d53c4f8..7690ec7c24d 100644
--- a/test/parallel/test-fs-truncate.js
+++ b/test/parallel/test-fs-truncate.js
@@ -180,8 +180,69 @@ function testFtruncate(cb) {
   fs.writeFileSync(file5, 'Hi');
   const fd = fs.openSync(file5, 'r+');
   process.on('exit', () => fs.closeSync(fd));
+
+  ['', false, null, {}, []].forEach((i) => {
+    common.expectsError(
+      () => fs.ftruncate(fd, i),
+      {
+        code: 'ERR_INVALID_ARG_TYPE',
+        type: TypeError,
+        message: 'The "len" argument must be of type number'
+      }
+    );
+  });
+
   fs.ftruncate(fd, undefined, common.mustCall(function(err) {
     assert.ifError(err);
     assert(fs.readFileSync(file5).equals(Buffer.from('')));
   }));
 }
+
+{
+  const file6 = path.resolve(tmp, 'truncate-file-6.txt');
+  fs.writeFileSync(file6, 'Hi');
+  const fd = fs.openSync(file6, 'r+');
+  process.on('exit', () => fs.closeSync(fd));
+  fs.ftruncate(fd, -1, common.mustCall(function(err) {
+    assert.ifError(err);
+    assert(fs.readFileSync(file6).equals(Buffer.from('')));
+  }));
+}
+
+['', false, null, undefined, {}, []].forEach((i) => {
+  common.expectsError(
+    () => fs.ftruncate(i),
+    {
+      code: 'ERR_INVALID_ARG_TYPE',
+      type: TypeError,
+      message: 'The "fd" argument must be of type number'
+    }
+  );
+  common.expectsError(
+    () => fs.ftruncateSync(i),
+    {
+      code: 'ERR_INVALID_ARG_TYPE',
+      type: TypeError,
+      message: 'The "fd" argument must be of type number'
+    }
+  );
+});
+
+[-1, 0xFFFFFFFF + 1].forEach((i) => {
+  common.expectsError(
+    () => fs.ftruncate(i),
+    {
+      code: 'ERR_OUT_OF_RANGE',
+      type: RangeError,
+      message: 'The "fd" argument is out of range'
+    }
+  );
+  common.expectsError(
+    () => fs.ftruncateSync(i),
+    {
+      code: 'ERR_OUT_OF_RANGE',
+      type: RangeError,
+      message: 'The "fd" argument is out of range'
+    }
+  );
+});