NickNaso

func carray2slice(array *C.int, len int) []C.int {
        var list []C.int
        sliceHeader := (*reflect.SliceHeader)((unsafe.Pointer(&list)))
        sliceHeader.Cap = len
        sliceHeader.Len = len
        sliceHeader.Data = uintptr(unsafe.Pointer(array))
        return list
}

NickNaso

upload(files) {
  const config = {
    onUploadProgress: function(progressEvent) {
      var percentCompleted = Math.round((progressEvent.loaded * 100) / progressEvent.total)
      console.log(percentCompleted)
    }
  }

  let data = new FormData()
  data.append('file', files[0])

NickNaso

You can install Node Nightlies/RCs via nvm using NVM_NODEJS_ORG_MIRROR environment variable.

Install latest Node RC

NVM_NODEJS_ORG_MIRROR=https://nodejs.org/download/rc/ nvm i node

Install latest Node.js Nightly

NVM_NODEJS_ORG_MIRROR=https://nodejs.org/download/nightly/ nvm i node

NickNaso

const addon = require('bindings')('addon');

addon.receiveModule('fs', require('fs'));
addon.receiveModule('crypto', require('crypto'));

console.log(addon.sendModule('fs') === require('fs'));
console.log(addon.sendModule('crypto') === require('crypto'));

NickNaso

#include <stdio.h>
#include <stdlib.h>

struct closure {
  void (* call)(struct closure *);

  int x;
};

NickNaso

// From callbacks to Promises to async functions

function callbackFunc(x, callback) {
  f1(x, (err1, result1) => {
    if (err1) {
      console.error(err1);
      callback(err1);
      return;
    }
    f2(result1, (err2, result2) => {

NickNaso

#include <stdio.h>
#include <node.h>

static void
NativeClassConstructor(const v8::FunctionCallbackInfo<v8::Value>& info) {
}

static void
NativeClassProtoMethod(const v8::FunctionCallbackInfo<v8::Value>& info) {
  fprintf(stderr, "NativeClassProtoMethod was called\n");

NickNaso

It is not usually recommended to reuse errors since the stack trace is attached whenever the error is instantiated.

However in some cases the overhead of doing that may affect performance, especially if the error is an exception that is known to occur frequently and is handled.

Only in these cases it may be advantagous to reuse the created Error. In all other cases getting a full stacktrace created at the time the exception occurs is to be preferred as it gives much better information needed to debug the problem.

Run

➝ node errors.js

NickNaso

Summary

Tried to improve debugging when an express middleware is wrapped to auto-handle errors of an asnync function.

Turns out the below reads a bit better than a return Promise.catch() implementation, but still, once we reach the central express error handler, the line of the wrapped function that caused the error isn't included.

Implementation

'use strict'

NickNaso

This is specifically tailored to Node.js binding projects in which case the C++ layer is always a library.

Clone gyp:

git clone --depth 1 https://chromium.googlesource.com/external/gyp.git gyp

Add the below common.gypi file in the root of the project.