From b3a7df7c6dddcc4aaf2106d569a2a4c017e9699c Mon Sep 17 00:00:00 2001
From: Joyee Cheung <joyeec9h3@gmail.com>
Date: Wed, 24 Jan 2018 09:20:30 +0800
Subject: [PATCH] fs: throw errors from fs.ftruncateSync in JS
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PR-URL: https://github.com/nodejs/node/pull/18348
Refs: https://github.com/nodejs/node/issues/18106
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
---
 lib/fs.js                               |  6 +++++-
 src/node_file.cc                        | 20 +++++++++++-------
 test/parallel/test-fs-error-messages.js | 27 +++++++++++++++++++++++++
 3 files changed, 45 insertions(+), 8 deletions(-)

diff --git a/lib/fs.js b/lib/fs.js
index 7087644674d..8eaba7984cc 100644
--- a/lib/fs.js
+++ b/lib/fs.js
@@ -995,7 +995,11 @@ fs.ftruncateSync = function(fd, len = 0) {
   validateUint32(fd, 'fd');
   validateLen(len);
   len = Math.max(0, len);
-  return binding.ftruncate(fd, len);
+  const ctx = {};
+  binding.ftruncate(fd, len, undefined, ctx);
+  if (ctx.errno !== undefined) {
+    throw new errors.uvException(ctx);
+  }
 };
 
 fs.rmdir = function(path, callback) {
diff --git a/src/node_file.cc b/src/node_file.cc
index 073902ce7de..10149b403e2 100644
--- a/src/node_file.cc
+++ b/src/node_file.cc
@@ -711,18 +711,24 @@ static void Rename(const FunctionCallbackInfo<Value>& args) {
 static void FTruncate(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
+  const int argc = args.Length();
+  CHECK_GE(argc, 3);
+
   CHECK(args[0]->IsInt32());
+  const int fd = args[0].As<Int32>()->Value();
+
   CHECK(args[1]->IsNumber());
+  const int64_t len = args[1].As<Integer>()->Value();
 
-  int fd = args[0]->Int32Value();
-  const int64_t len = args[1]->IntegerValue();
-
-  if (args[2]->IsObject()) {
-    CHECK_EQ(args.Length(), 3);
+  if (args[2]->IsObject()) {  // ftruncate(fd, len, req)
+    CHECK_EQ(argc, 3);
     AsyncCall(env, args, "ftruncate", UTF8, AfterNoArgs,
               uv_fs_ftruncate, fd, len);
-  } else {
-    SYNC_CALL(ftruncate, 0, fd, len)
+  } else {  // ftruncate(fd, len, undefined, ctx)
+    CHECK_EQ(argc, 4);
+    fs_req_wrap req_wrap;
+    SyncCall(env, args[3], &req_wrap, "ftruncate",
+             uv_fs_ftruncate, fd, len);
   }
 }
 
diff --git a/test/parallel/test-fs-error-messages.js b/test/parallel/test-fs-error-messages.js
index ef38652d7a3..b7e7ab6a2cc 100644
--- a/test/parallel/test-fs-error-messages.js
+++ b/test/parallel/test-fs-error-messages.js
@@ -455,3 +455,30 @@ function re(literals, ...values) {
     validateError
   );
 }
+
+// ftruncate
+{
+  const validateError = (err) => {
+    assert.strictEqual(err.syscall, 'ftruncate');
+    // Could be EBADF or EINVAL, depending on the platform
+    if (err.code === 'EBADF') {
+      assert.strictEqual(err.message, 'EBADF: bad file descriptor, ftruncate');
+      assert.strictEqual(err.errno, uv.UV_EBADF);
+    } else {
+      assert.strictEqual(err.message, 'EINVAL: invalid argument, ftruncate');
+      assert.strictEqual(err.errno, uv.UV_EINVAL);
+      assert.strictEqual(err.code, 'EINVAL');
+    }
+    return true;
+  };
+
+  const fd = fs.openSync(existingFile, 'r');
+  fs.closeSync(fd);
+
+  fs.ftruncate(fd, 4, common.mustCall(validateError));
+
+  assert.throws(
+    () => fs.ftruncateSync(fd, 4),
+    validateError
+  );
+}