fs: replace bad_args macro with concrete error msg

Instead of throwing an error with `Bad arguments` the fs methods
return a concrete error message. If an argument is missing, the
methods throw an error with the information, what is missing.
In case of a type mismatch, they throw an error with some hints,
what datatype is expected.

PR-URL: https://github.com/nodejs/node/pull/2495
Reviewed-By: Trevor Norris <trev.norris@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>

diff --git a/src/node_file.cc b/src/node_file.cc
index 5eacf9a..f10b99e 100644 (file)
--- a/src/node_file.cc
+++ b/src/node_file.cc
@@ -47,8 +47,6 @@ using v8::Value;
 
 #define TYPE_ERROR(msg) env->ThrowTypeError(msg)
 
-#define THROW_BAD_ARGS TYPE_ERROR("Bad argument")
-
 #define GET_OFFSET(a) ((a)->IsNumber() ? (a)->IntegerValue() : -1)
 
 class FSReqWrap: public ReqWrap<uv_fs_t> {
@@ -306,7 +304,7 @@ static void Access(const FunctionCallbackInfo<Value>& args) {
   HandleScope scope(env->isolate());
 
   if (args.Length() < 2)
-    return THROW_BAD_ARGS;
+    return TYPE_ERROR("path and mode are required");
   if (!args[0]->IsString())
     return TYPE_ERROR("path must be a string");
   if (!args[1]->IsInt32())
@@ -326,9 +324,10 @@ static void Access(const FunctionCallbackInfo<Value>& args) {
 static void Close(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  if (args.Length() < 1 || !args[0]->IsInt32()) {
-    return THROW_BAD_ARGS;
-  }
+  if (args.Length() < 1)
+    return TYPE_ERROR("fd is required");
+  if (!args[0]->IsInt32())
+    return TYPE_ERROR("fd must be a file descriptor");
 
   int fd = args[0]->Int32Value();
 
@@ -559,9 +558,10 @@ static void LStat(const FunctionCallbackInfo<Value>& args) {
 static void FStat(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  if (args.Length() < 1 || !args[0]->IsInt32()) {
-    return THROW_BAD_ARGS;
-  }
+  if (args.Length() < 1)
+    return TYPE_ERROR("fd is required");
+  if (!args[0]->IsInt32())
+    return TYPE_ERROR("fd must be a file descriptor");
 
   int fd = args[0]->Int32Value();
 
@@ -678,9 +678,10 @@ static void Rename(const FunctionCallbackInfo<Value>& args) {
 static void FTruncate(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  if (args.Length() < 2 || !args[0]->IsInt32()) {
-    return THROW_BAD_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");
 
   int fd = args[0]->Int32Value();
 
@@ -706,9 +707,10 @@ static void FTruncate(const FunctionCallbackInfo<Value>& args) {
 static void Fdatasync(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  if (args.Length() < 1 || !args[0]->IsInt32()) {
-    return THROW_BAD_ARGS;
-  }
+  if (args.Length() < 1)
+    return TYPE_ERROR("fd is required");
+  if (!args[0]->IsInt32())
+    return TYPE_ERROR("fd must be a file descriptor");
 
   int fd = args[0]->Int32Value();
 
@@ -722,9 +724,10 @@ static void Fdatasync(const FunctionCallbackInfo<Value>& args) {
 static void Fsync(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  if (args.Length() < 1 || !args[0]->IsInt32()) {
-    return THROW_BAD_ARGS;
-  }
+  if (args.Length() < 1)
+    return TYPE_ERROR("fd is required");
+  if (!args[0]->IsInt32())
+    return TYPE_ERROR("fd must be a file descriptor");
 
   int fd = args[0]->Int32Value();
 
@@ -772,9 +775,12 @@ static void RMDir(const FunctionCallbackInfo<Value>& args) {
 static void MKDir(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  if (args.Length() < 2 || !args[0]->IsString() || !args[1]->IsInt32()) {
-    return THROW_BAD_ARGS;
-  }
+  if (args.Length() < 2)
+    return TYPE_ERROR("path and mode are required");
+  if (!args[0]->IsString())
+    return TYPE_ERROR("path must be a string");
+  if (!args[1]->IsInt32())
+    return TYPE_ERROR("mode must be an integer");
 
   node::Utf8Value path(env->isolate(), args[0]);
   int mode = static_cast<int>(args[1]->Int32Value());
@@ -990,9 +996,12 @@ static void WriteString(const FunctionCallbackInfo<Value>& args) {
 static void Read(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  if (args.Length() < 2 || !args[0]->IsInt32()) {
-    return THROW_BAD_ARGS;
-  }
+  if (args.Length() < 2)
+    return TYPE_ERROR("fd and buffer are required");
+  if (!args[0]->IsInt32())
+    return TYPE_ERROR("fd must be a file descriptor");
+  if (!Buffer::HasInstance(args[1]))
+    return TYPE_ERROR("Second argument needs to be a buffer");
 
   int fd = args[0]->Int32Value();
 
@@ -1003,10 +1012,6 @@ static void Read(const FunctionCallbackInfo<Value>& args) {
 
   char * buf = nullptr;
 
-  if (!Buffer::HasInstance(args[1])) {
-    return env->ThrowError("Second argument needs to be a buffer");
-  }
-
   Local<Object> buffer_obj = args[1]->ToObject(env->isolate());
   char *buffer_data = Buffer::Data(buffer_obj);
   size_t buffer_length = Buffer::Length(buffer_obj);
@@ -1043,9 +1048,13 @@ static void Read(const FunctionCallbackInfo<Value>& args) {
 static void Chmod(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  if (args.Length() < 2 || !args[0]->IsString() || !args[1]->IsInt32()) {
-    return THROW_BAD_ARGS;
-  }
+  if (args.Length() < 2)
+    return TYPE_ERROR("path and mode are required");
+  if (!args[0]->IsString())
+    return TYPE_ERROR("path must be a string");
+  if (!args[1]->IsInt32())
+    return TYPE_ERROR("mode must be an integer");
+
   node::Utf8Value path(env->isolate(), args[0]);
   int mode = static_cast<int>(args[1]->Int32Value());
 
@@ -1063,9 +1072,13 @@ static void Chmod(const FunctionCallbackInfo<Value>& args) {
 static void FChmod(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  if (args.Length() < 2 || !args[0]->IsInt32() || !args[1]->IsInt32()) {
-    return THROW_BAD_ARGS;
-  }
+  if (args.Length() < 2)
+    return TYPE_ERROR("fd and mode are required");
+  if (!args[0]->IsInt32())
+    return TYPE_ERROR("fd must be a file descriptor");
+  if (!args[1]->IsInt32())
+    return TYPE_ERROR("mode must be an integer");
+
   int fd = args[0]->Int32Value();
   int mode = static_cast<int>(args[1]->Int32Value());