Roughing out the demo app

node_modules/errorhandler/index.js

@@ -0,0 +1,198 @@
+/*!
+ * errorhandler
+ * Copyright(c) 2010 Sencha Inc.
+ * Copyright(c) 2011 TJ Holowaychuk
+ * Copyright(c) 2014 Jonathan Ong
+ * Copyright(c) 2014-2015 Douglas Christopher Wilson
+ * MIT Licensed
+ */
+
+'use strict'
+
+/**
+ * Module dependencies.
+ * @private
+ */
+
+var accepts = require('accepts')
+var escapeHtml = require('escape-html')
+var fs = require('fs')
+var path = require('path')
+var util = require('util')
+
+/**
+ * Module variables.
+ * @private
+ */
+
+var DOUBLE_SPACE_REGEXP = /\x20{2}/g
+var NEW_LINE_REGEXP = /\n/g
+var STYLESHEET = fs.readFileSync(path.join(__dirname, '/public/style.css'), 'utf8')
+var TEMPLATE = fs.readFileSync(path.join(__dirname, '/public/error.html'), 'utf8')
+var inspect = util.inspect
+var toString = Object.prototype.toString
+
+/* istanbul ignore next */
+var defer = typeof setImmediate === 'function'
+  ? setImmediate
+  : function (fn) { process.nextTick(fn.bind.apply(fn, arguments)) }
+
+/**
+ * Error handler:
+ *
+ * Development error handler, providing stack traces
+ * and error message responses for requests accepting text, html,
+ * or json.
+ *
+ * Text:
+ *
+ *   By default, and when _text/plain_ is accepted a simple stack trace
+ *   or error message will be returned.
+ *
+ * JSON:
+ *
+ *   When _application/json_ is accepted, connect will respond with
+ *   an object in the form of `{ "error": error }`.
+ *
+ * HTML:
+ *
+ *   When accepted connect will output a nice html stack trace.
+ *
+ * @return {Function}
+ * @api public
+ */
+
+exports = module.exports = function errorHandler (options) {
+  // get environment
+  var env = process.env.NODE_ENV || 'development'
+
+  // get options
+  var opts = options || {}
+
+  // get log option
+  var log = opts.log === undefined
+    ? env !== 'test'
+    : opts.log
+
+  if (typeof log !== 'function' && typeof log !== 'boolean') {
+    throw new TypeError('option log must be function or boolean')
+  }
+
+  // default logging using console.error
+  if (log === true) {
+    log = logerror
+  }
+
+  return function errorHandler (err, req, res, next) {
+    // respect err.statusCode
+    if (err.statusCode) {
+      res.statusCode = err.statusCode
+    }
+
+    // respect err.status
+    if (err.status) {
+      res.statusCode = err.status
+    }
+
+    // default status code to 500
+    if (res.statusCode < 400) {
+      res.statusCode = 500
+    }
+
+    // log the error
+    var str = stringify(err)
+    if (log) {
+      defer(log, err, str, req, res)
+    }
+
+    // cannot actually respond
+    if (res._header) {
+      return req.socket.destroy()
+    }
+
+    // negotiate
+    var accept = accepts(req)
+    var type = accept.type('html', 'json', 'text')
+
+    // Security header for content sniffing
+    res.setHeader('X-Content-Type-Options', 'nosniff')
+
+    // html
+    if (type === 'html') {
+      var isInspect = !err.stack && String(err) === toString.call(err)
+      var errorHtml = !isInspect
+        ? escapeHtmlBlock(str.split('\n', 1)[0] || 'Error')
+        : 'Error'
+      var stack = !isInspect
+        ? String(str).split('\n').slice(1)
+        : [str]
+      var stackHtml = stack
+        .map(function (v) { return '<li>' + escapeHtmlBlock(v) + '</li>' })
+        .join('')
+      var body = TEMPLATE
+        .replace('{style}', STYLESHEET)
+        .replace('{stack}', stackHtml)
+        .replace('{title}', escapeHtml(exports.title))
+        .replace('{statusCode}', res.statusCode)
+        .replace(/\{error\}/g, errorHtml)
+      res.setHeader('Content-Type', 'text/html; charset=utf-8')
+      res.end(body)
+    // json
+    } else if (type === 'json') {
+      var error = { message: err.message, stack: err.stack }
+      for (var prop in err) error[prop] = err[prop]
+      var json = JSON.stringify({ error: error }, null, 2)
+      res.setHeader('Content-Type', 'application/json; charset=utf-8')
+      res.end(json)
+    // plain text
+    } else {
+      res.setHeader('Content-Type', 'text/plain; charset=utf-8')
+      res.end(str)
+    }
+  }
+}
+
+/**
+ * Template title, framework authors may override this value.
+ */
+
+exports.title = 'Connect'
+
+/**
+ * Escape a block of HTML, preserving whitespace.
+ * @api private
+ */
+
+function escapeHtmlBlock (str) {
+  return escapeHtml(str)
+    .replace(DOUBLE_SPACE_REGEXP, ' &nbsp;')
+    .replace(NEW_LINE_REGEXP, '<br>')
+}
+
+/**
+ * Stringify a value.
+ * @api private
+ */
+
+function stringify (val) {
+  var stack = val.stack
+
+  if (stack) {
+    return String(stack)
+  }
+
+  var str = String(val)
+
+  return str === toString.call(val)
+    ? inspect(val)
+    : str
+}
+
+/**
+ * Log error to console.
+ * @api private
+ */
+
+function logerror (err, str) {
+  console.error(str || err.stack)
+}