expose function to get error strings

README.md

@@ -2,6 +2,26 @@
 
 This is an experimental port of [libcurl](https://curl.se/libcurl/) to WebAssembly for use in the browser. It provides an interface compatible with the [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API), allowing you to proxy HTTPS requests from the browser with full TLS encryption. Unlike previous implementations, the proxy server cannot read the contents of your requests. 
 
+## Table of Contents:
+- [Features](#features)
+- [Building](#building)
+- [Javascript API](#javascript-api)
+  * [Importing the Library](#importing-the-library)
+  * [Making HTTP Requests](#making-http-requests)
+  * [Creating WebSocket Connections](#creating-websocket-connections)
+  * [Using TLS Sockets](#using-tls-sockets)
+  * [Changing the Network Transport](#changing-the-network-transport)
+  * [Changing the Websocket Proxy URL](#changing-the-websocket-proxy-url)
+  * [Getting Libcurl's Output](#getting-libcurl-s-output)
+  * [Getting Error Strings](#getting-error-strings)
+  * [Getting Version Info](#getting-version-info)
+  * [Getting the CA Certificates Bundle](#getting-the-ca-certificates-bundle)
+- [Proxy Server](#proxy-server)
+- [Copyright](#copyright)
+  * [Copyright Notice](#copyright-notice)
+
+<small><i><a href='http://ecotrust-canada.github.io/markdown-toc/'>Table of contents generated with markdown-toc</a></i></small>
+
 ## Features:
 - Fetch compatible API
 - End to end encryption between the browser and the destination server
@@ -176,6 +196,14 @@ Libcurl.js will also output some error messages to the browser console. You can
 
 This may be useful if you are running libcurl.js inside a web worker and do not have access to the regular console API.
 
+### Getting Error Strings:
+Libcurl.js reports errors based on the [error codes](https://curl.se/libcurl/c/libcurl-errors.html) defined by the libcurl C library. The `libcurl.get_error_string` function can be used to get an error string from an error code. 
+
+```js
+console.log(libcurl.get_error_string(56));
+//"Failure when receiving data from the peer"
+```
+
 ### Getting Version Info:
 You can get version information from the `libcurl.version` object. This object will also contain the versions of all the C libraries that libcurl.js uses. `libcurl.version.lib` returns the version of libcurl.js itself. 
 

client/javascript/main.js

@@ -244,6 +244,7 @@ api = {
   CurlWebSocket: CurlWebSocket,
   TLSSocket: TLSSocket,
   get_cacert: get_cacert,
+  get_error_string: get_error_str,
 
   wisp_connections: _wisp_connections,
   WispConnection: WispConnection,

client/javascript/websocket.js

@@ -106,6 +106,7 @@ class CurlWebSocket {
     this.connected = false;
 
     if (error) {
+      error_msg(`Websocket "${this.url}" encountered error code ${error}: ${get_error_str(error)}`);
       this.onerror(error);
     }
     else {

client/javascript/ws_polyfill.js

@@ -44,7 +44,6 @@ class FakeWebSocket extends EventTarget {
 
     this.socket.onerror = (error) => {
       this.status = this.CLOSED;
-      error_msg(`websocket ${this.url} encountered an error (${error})`);
       let error_event = new Event("error");
       this.dispatchEvent(error_event);
       this.onerror(error_event);

client/package.json

@@ -1,6 +1,6 @@
 {
   "name": "libcurl.js",
-  "version": "0.4.1",
+  "version": "0.4.2",
   "description": "An experimental port of libcurl to WebAssembly for use in the browser.",
   "main": "libcurl.mjs",
   "scripts": {