Remove existing implementation of StartupExceptionPage and use the one in Common

[Fixes #831] Fix startup exception page to handle flattened exceptions

src/Microsoft.AspNetCore.Hosting/Internal/WebHost.cs

@@ -5,16 +5,20 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
+using System.Reflection;
+using System.Runtime.InteropServices;
 using System.Threading;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting.Builder;
 using Microsoft.AspNetCore.Hosting.Server;
 using Microsoft.AspNetCore.Hosting.Server.Features;
+using Microsoft.AspNetCore.Hosting.Views;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Http.Features;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.StackTrace.Sources;
 
 namespace Microsoft.AspNetCore.Hosting.Internal
 {
@@ -168,15 +172,44 @@ namespace Microsoft.AspNetCore.Hosting.Internal
                 // Generate an HTML error page.
                 var hostingEnv = _applicationServices.GetRequiredService<IHostingEnvironment>();
                 var showDetailedErrors = hostingEnv.IsDevelopment() || _options.DetailedErrors;
-                var errorBytes = StartupExceptionPage.GenerateErrorHtml(showDetailedErrors, ex);
 
+                var model = new ErrorPageModel();
+                var runtimeType = Microsoft.Extensions.Internal.RuntimeEnvironment.RuntimeType;
+                model.RuntimeDisplayName = (runtimeType == "CoreCLR") ? ".NET Core" : runtimeType == "CLR" ? ".NET Framework" : "Mono";
+#if NETSTANDARD1_3
+                var systemRuntimeAssembly = typeof(System.ComponentModel.DefaultValueAttribute).GetTypeInfo().Assembly;
+                var assemblyVersion = new AssemblyName(systemRuntimeAssembly.FullName).Version.ToString();
+                var clrVersion = assemblyVersion;
+#else
+                var clrVersion = Environment.Version.ToString();
+#endif
+                model.RuntimeArchitecture = RuntimeInformation.ProcessArchitecture.ToString();
+                var currentAssembly = typeof(ErrorPage).GetTypeInfo().Assembly;
+                model.CurrentAssemblyVesion = currentAssembly
+                    .GetCustomAttribute<AssemblyInformationalVersionAttribute>()
+                    .InformationalVersion;
+                model.ClrVersion = clrVersion;
+                model.OperatingSystemDescription = RuntimeInformation.OSDescription;
+
+                if (showDetailedErrors)
+                {
+                    var exceptionDetailProvider = new ExceptionDetailsProvider(
+                        hostingEnv.ContentRootFileProvider,
+                        sourceCodeLineCount: 6);
+
+                    model.ErrorDetails = exceptionDetailProvider.GetDetails(ex);
+                }
+                else
+                {
+                    model.ErrorDetails = new ExceptionDetails[0];
+                }
+
+                var errorPage = new ErrorPage(model);
                 return context =>
                 {
                     context.Response.StatusCode = 500;
-                    context.Response.Headers["Cache-Control"] = "private, max-age=0";
+                    context.Response.Headers["Cache-Control"] = "no-cache";
-                    context.Response.ContentType = "text/html; charset=utf-8";
+                    return errorPage.ExecuteAsync(context);
-                    context.Response.ContentLength = errorBytes.Length;
-                    return context.Response.Body.WriteAsync(errorBytes, 0, errorBytes.Length);
                 };
             }
         }

src/Microsoft.AspNetCore.Hosting/Properties/Resources.Designer.cs

@@ -0,0 +1,78 @@
+// <auto-generated />
+namespace Microsoft.AspNetCore.Hosting
+{
+    using System.Globalization;
+    using System.Reflection;
+    using System.Resources;
+
+    internal static class Resources
+    {
+        private static readonly ResourceManager _resourceManager
+            = new ResourceManager("Microsoft.AspNetCore.Hosting.Resources", typeof(Resources).GetTypeInfo().Assembly);
+
+        /// <summary>
+        /// Internal Server Error
+        /// </summary>
+        internal static string ErrorPageHtml_Title
+        {
+            get { return GetString("ErrorPageHtml_Title"); }
+        }
+
+        /// <summary>
+        /// Internal Server Error
+        /// </summary>
+        internal static string FormatErrorPageHtml_Title()
+        {
+            return GetString("ErrorPageHtml_Title");
+        }
+
+        /// <summary>
+        /// An error occurred while starting the application.
+        /// </summary>
+        internal static string ErrorPageHtml_UnhandledException
+        {
+            get { return GetString("ErrorPageHtml_UnhandledException"); }
+        }
+
+        /// <summary>
+        /// An error occurred while starting the application.
+        /// </summary>
+        internal static string FormatErrorPageHtml_UnhandledException()
+        {
+            return GetString("ErrorPageHtml_UnhandledException");
+        }
+
+        /// <summary>
+        /// Unknown location
+        /// </summary>
+        internal static string ErrorPageHtml_UnknownLocation
+        {
+            get { return GetString("ErrorPageHtml_UnknownLocation"); }
+        }
+
+        /// <summary>
+        /// Unknown location
+        /// </summary>
+        internal static string FormatErrorPageHtml_UnknownLocation()
+        {
+            return GetString("ErrorPageHtml_UnknownLocation");
+        }
+
+        private static string GetString(string name, params string[] formatterNames)
+        {
+            var value = _resourceManager.GetString(name);
+
+            System.Diagnostics.Debug.Assert(value != null);
+
+            if (formatterNames != null)
+            {
+                for (var i = 0; i < formatterNames.Length; i++)
+                {
+                    value = value.Replace("{" + formatterNames[i] + "}", "{" + i + "}");
+                }
+            }
+
+            return value;
+        }
+    }
+}

src/Microsoft.AspNetCore.Hosting/Resources.resx

@@ -0,0 +1,129 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!-- 
+    Microsoft ResX Schema 
+    
+    Version 2.0
+    
+    The primary goals of this format is to allow a simple XML format 
+    that is mostly human readable. The generation and parsing of the 
+    various data types are done through the TypeConverter classes 
+    associated with the data types.
+    
+    Example:
+    
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+                
+    There are any number of "resheader" rows that contain simple 
+    name/value pairs.
+    
+    Each data row contains a name, and value. The row also contains a 
+    type or mimetype. Type corresponds to a .NET class that support 
+    text/value conversion through the TypeConverter architecture. 
+    Classes that don't support this are serialized and stored with the 
+    mimetype set.
+    
+    The mimetype is used for serialized objects, and tells the 
+    ResXResourceReader how to depersist the object. This is currently not 
+    extensible. For a given mimetype the value must be set accordingly:
+    
+    Note - application/x-microsoft.net.object.binary.base64 is the format 
+    that the ResXResourceWriter will generate, however the reader can 
+    read any of the formats listed below.
+    
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array 
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <data name="ErrorPageHtml_Title" xml:space="preserve">
+    <value>Internal Server Error</value>
+  </data>
+  <data name="ErrorPageHtml_UnhandledException" xml:space="preserve">
+    <value>An error occurred while starting the application.</value>
+  </data>
+  <data name="ErrorPageHtml_UnknownLocation" xml:space="preserve">
+    <value>Unknown location</value>
+  </data>
+</root>

src/Microsoft.AspNetCore.Hosting/Startup/ExceptionPage/Views/ErrorPage.cshtml

@@ -0,0 +1,162 @@
+@using System
+@using System.Globalization
+@using System.Linq
+@using System.Net
+@using System.Reflection
+@using Microsoft.AspNetCore.Hosting.Views
+
+@functions
+{
+    public ErrorPage(ErrorPageModel model)
+    {
+        Model = model;
+    }
+
+    public ErrorPageModel Model { get; set; }
+}
+@{
+    Response.ContentType = "text/html; charset=utf-8";
+    var location = string.Empty;
+}
+<!DOCTYPE html>
+<html lang="@CultureInfo.CurrentUICulture.TwoLetterISOLanguageName" xmlns="http://www.w3.org/1999/xhtml">
+    <head>
+        <meta charset="utf-8" />
+        <title>@Resources.ErrorPageHtml_Title</title>
+        <style>
+            <%$ include: ErrorPage.css %>
+        </style>
+    </head>
+    <body>
+        <h1>@Resources.ErrorPageHtml_UnhandledException</h1>
+        @foreach (var errorDetail in Model.ErrorDetails)
+        {
+            <div class="titleerror">@errorDetail.Error.GetType().Name: @{ Output.Write(HtmlEncodeAndReplaceLineBreaks(errorDetail.Error.Message)); }</div>
+            @{
+                var firstFrame = errorDetail.StackFrames.FirstOrDefault();
+                if (firstFrame != null)
+                {
+                    location = firstFrame.Function;
+                }
+            }
+            if (!string.IsNullOrEmpty(location) && firstFrame != null && !string.IsNullOrEmpty(firstFrame.File))
+            {
+                <p class="location">@location in <code title="@firstFrame.File">@System.IO.Path.GetFileName(firstFrame.File)</code>, line @firstFrame.Line</p>
+            }
+            else if (!string.IsNullOrEmpty(location))
+            {
+                <p class="location">@location</p>
+            }
+            else
+            {
+                <p class="location">@Resources.ErrorPageHtml_UnknownLocation</p>
+            }
+
+            var reflectionTypeLoadException = errorDetail.Error as ReflectionTypeLoadException;
+            if (reflectionTypeLoadException != null)
+            {
+                if (reflectionTypeLoadException.LoaderExceptions.Length > 0)
+                {
+                    <h3>Loader Exceptions:</h3>
+                    <ul>
+                        @foreach (var ex in reflectionTypeLoadException.LoaderExceptions)
+                        {
+                            <li>@ex.Message</li>
+                        }
+                    </ul>
+                }
+            }
+        }
+        <div id="stackpage" class="page">
+            <ul>
+                @{
+                    var exceptionCount = 0;
+                    var stackFrameCount = 0;
+                    var exceptionDetailId = "";
+                    var frameId = "";
+                }
+                @foreach (var errorDetail in Model.ErrorDetails)
+                {
+                    @{
+                        exceptionCount++;
+                        exceptionDetailId = "exceptionDetail" + exceptionCount;
+                    }
+                    <li>
+                        <h2 class="stackerror">@errorDetail.Error.GetType().Name: @errorDetail.Error.Message</h2>
+                        <ul>
+                        @foreach (var frame in errorDetail.StackFrames)
+                        {
+                            @{
+                                stackFrameCount++;
+                                frameId = "frame" + stackFrameCount;
+                            }
+                            <li class="frame" id="@frameId">
+                                @if (string.IsNullOrEmpty(frame.File))
+                                {
+                                    <h3>@frame.Function</h3>
+                                }
+                                else
+                                {
+                                    <h3>@frame.Function in <code title="@frame.File">@System.IO.Path.GetFileName(frame.File)</code></h3>
+                                }
+
+                                @if (frame.Line != 0 && frame.ContextCode.Any())
+                                {
+                                    <button class="expandCollapseButton" data-frameId="@frameId">+</button>
+                                    <div class="source">
+                                        @if (frame.PreContextCode.Any())
+                                        {
+                                            <ol start="@frame.PreContextLine" class="collapsible">
+                                                @foreach (var line in frame.PreContextCode)
+                                                {
+                                                    <li><span>@line</span></li>
+                                                }
+                                            </ol>
+                                        }
+
+                                        <ol start="@frame.Line" class="highlight">
+                                            @foreach (var line in frame.ContextCode)
+                                            {
+                                                <li><span>@line</span></li>
+                                            }
+                                        </ol>
+
+                                        @if (frame.PostContextCode.Any())
+                                        {
+                                            <ol start='@(frame.Line + 1)' class="collapsible">
+                                                @foreach (var line in frame.PostContextCode)
+                                                {
+                                                    <li><span>@line</span></li>
+                                                }
+                                            </ol>
+                                        }
+                                    </div>
+                                }
+                            </li>
+                        }
+                        </ul>
+                    </li>
+                    <li>
+                        <br/>
+                        <div class="rawExceptionBlock">
+                            <div class="showRawExceptionContainer">
+                                <button class="showRawException" data-exceptionDetailId="@exceptionDetailId">Show raw exception details</button>
+                            </div>
+                            <div id="@exceptionDetailId" class="rawExceptionDetails">
+                                <pre class="rawExceptionStackTrace">@errorDetail.Error.ToString()</pre>
+                            </div>
+                        </div>
+                    </li>
+                }
+            </ul>
+        </div>
+        <footer>
+            @Model.RuntimeDisplayName @Model.RuntimeArchitecture v@(Model.ClrVersion) &nbsp;&nbsp;&nbsp;|&nbsp;&nbsp;&nbsp;Microsoft.AspNetCore.Hosting version @Model.CurrentAssemblyVesion &nbsp;&nbsp;&nbsp;|&nbsp;&nbsp;&nbsp; @Model.OperatingSystemDescription &nbsp;&nbsp;&nbsp;|&nbsp;&nbsp;&nbsp;<a href="http://go.microsoft.com/fwlink/?LinkId=517394">Need help?</a>
+        </footer>
+        <script>
+            //<!--
+            <%$ include: ErrorPage.js %>
+            //-->
+        </script>
+</body>
+</html>

src/Microsoft.AspNetCore.Hosting/Startup/ExceptionPage/Views/ErrorPage.css

@@ -0,0 +1,195 @@
+body {
+    font-family: 'Segoe UI', Tahoma, Arial, Helvetica, sans-serif;
+    font-size: .813em;
+    color: #222;
+}
+
+h1, h2, h3, h4, h5 {
+    /*font-family: 'Segoe UI',Tahoma,Arial,Helvetica,sans-serif;*/
+    font-weight: 100;
+}
+
+h1 {
+    color: #44525e;
+    margin: 15px 0 15px 0;
+}
+
+h2 {
+    margin: 10px 5px 0 0;
+}
+
+h3 {
+    color: #363636;
+    margin: 5px 5px 0 0;
+}
+
+code {
+    font-family: Consolas, "Courier New", courier, monospace;
+}
+
+body .titleerror {
+    padding: 3px 3px 6px 3px;
+    display: block;
+    font-size: 1.5em;
+    font-weight: 100;
+}
+
+body .location {
+    margin: 3px 0 10px 30px;
+}
+
+#header {
+    font-size: 18px;
+    padding: 15px 0;
+    border-top: 1px #ddd solid;
+    border-bottom: 1px #ddd solid;
+    margin-bottom: 0;
+}
+
+    #header li {
+        display: inline;
+        margin: 5px;
+        padding: 5px;
+        color: #a0a0a0;
+        cursor: pointer;
+    }
+
+    #header .selected {
+        background: #44c5f2;
+        color: #fff;
+    }
+
+#stackpage ul {
+    list-style: none;
+    padding-left: 0;
+    margin: 0;
+    /*border-bottom: 1px #ddd solid;*/
+}
+
+#stackpage .details {
+    font-size: 1.2em;
+    padding: 3px;
+    color: #000;
+}
+
+#stackpage .stackerror {
+    padding: 5px;
+    border-bottom: 1px #ddd solid;
+}
+
+
+#stackpage .frame {
+    padding: 0;
+    margin: 0 0 0 30px;
+}
+
+    #stackpage .frame h3 {
+        padding: 2px;
+        margin: 0;
+    }
+
+#stackpage .source {
+    padding: 0 0 0 30px;
+}
+
+    #stackpage .source ol li {
+        font-family: Consolas, "Courier New", courier, monospace;
+        white-space: pre;
+        background-color: #fbfbfb;
+    }
+
+#stackpage .frame .source .highlight li span {
+    color: #FF0000;
+}
+
+#stackpage .source ol.collapsible li {
+    color: #888;
+}
+
+    #stackpage .source ol.collapsible li span {
+        color: #606060;
+    }
+
+.page table {
+    border-collapse: separate;
+    border-spacing: 0;
+    margin: 0 0 20px;
+}
+
+.page th {
+    vertical-align: bottom;
+    padding: 10px 5px 5px 5px;
+    font-weight: 400;
+    color: #a0a0a0;
+    text-align: left;
+}
+
+.page td {
+    padding: 3px 10px;
+}
+
+.page th, .page td {
+    border-right: 1px #ddd solid;
+    border-bottom: 1px #ddd solid;
+    border-left: 1px transparent solid;
+    border-top: 1px transparent solid;
+    box-sizing: border-box;
+}
+
+    .page th:last-child, .page td:last-child {
+        border-right: 1px transparent solid;
+    }
+
+.page .length {
+    text-align: right;
+}
+
+a {
+    color: #1ba1e2;
+    text-decoration: none;
+}
+
+    a:hover {
+        color: #13709e;
+        text-decoration: underline;
+    }
+
+.showRawException {
+    cursor: pointer;
+    color: #44c5f2;
+    background-color: transparent;
+    font-size: 1.2em;
+    text-align: left;
+    text-decoration: none;
+    display: inline-block;
+    border: 0;
+    padding: 0;
+}
+
+.rawExceptionStackTrace {
+    font-size: 1.2em;
+}
+
+.rawExceptionBlock {
+    border-top: 1px #ddd solid;
+    border-bottom: 1px #ddd solid;
+}
+
+.showRawExceptionContainer {
+    margin-top: 10px;
+    margin-bottom: 10px;
+}
+
+.expandCollapseButton {
+    cursor: pointer;
+    float: left;
+    height: 16px;
+    width: 16px;
+    font-size: 10px;
+    position: absolute;
+    left: 10px;
+    background-color: #eee;
+    padding: 0;
+    border: 0;
+    margin: 0;
+}

src/Microsoft.AspNetCore.Hosting/Startup/ExceptionPage/Views/ErrorPage.js

@@ -0,0 +1,192 @@
+(function (window, undefined) {
+    "use strict";
+
+    function ns(selector, element) {
+        return new NodeCollection(selector, element);
+    }
+
+    function NodeCollection(selector, element) {
+        this.items = [];
+        element = element || window.document;
+
+        var nodeList;
+
+        if (typeof (selector) === "string") {
+            nodeList = element.querySelectorAll(selector);
+            for (var i = 0, l = nodeList.length; i < l; i++) {
+                this.items.push(nodeList.item(i));
+            }
+        }
+    }
+
+    NodeCollection.prototype = {
+        each: function (callback) {
+            for (var i = 0, l = this.items.length; i < l; i++) {
+                callback(this.items[i], i);
+            }
+            return this;
+        },
+
+        children: function (selector) {
+            var children = [];
+
+            this.each(function (el) {
+                children = children.concat(ns(selector, el).items);
+            });
+
+            return ns(children);
+        },
+
+        hide: function () {
+            this.each(function (el) {
+                el.style.display = "none";
+            });
+
+            return this;
+        },
+
+        toggle: function () {
+            this.each(function (el) {
+                el.style.display = el.style.display === "none" ? "" : "none";
+            });
+
+            return this;
+        },
+
+        show: function () {
+            this.each(function (el) {
+                el.style.display = "";
+            });
+
+            return this;
+        },
+
+        addClass: function (className) {
+            this.each(function (el) {
+                var existingClassName = el.className,
+                    classNames;
+                if (!existingClassName) {
+                    el.className = className;
+                } else {
+                    classNames = existingClassName.split(" ");
+                    if (classNames.indexOf(className) < 0) {
+                        el.className = existingClassName + " " + className;
+                    }
+                }
+            });
+
+            return this;
+        },
+
+        removeClass: function (className) {
+            this.each(function (el) {
+                var existingClassName = el.className,
+                    classNames, index;
+                if (existingClassName === className) {
+                    el.className = "";
+                } else if (existingClassName) {
+                    classNames = existingClassName.split(" ");
+                    index = classNames.indexOf(className);
+                    if (index > 0) {
+                        classNames.splice(index, 1);
+                        el.className = classNames.join(" ");
+                    }
+                }
+            });
+
+            return this;
+        },
+
+        attr: function (name) {
+            if (this.items.length === 0) {
+                return null;
+            }
+
+            return this.items[0].getAttribute(name);
+        },
+
+        on: function (eventName, handler) {
+            this.each(function (el, idx) {
+                var callback = function (e) {
+                    e = e || window.event;
+                    if (!e.which && e.keyCode) {
+                        e.which = e.keyCode; // Normalize IE8 key events
+                    }
+                    handler.apply(el, [e]);
+                };
+
+                if (el.addEventListener) { // DOM Events
+                    el.addEventListener(eventName, callback, false);
+                } else if (el.attachEvent) { // IE8 events
+                    el.attachEvent("on" + eventName, callback);
+                } else {
+                    el["on" + type] = callback;
+                }
+            });
+
+            return this;
+        },
+
+        click: function (handler) {
+            return this.on("click", handler);
+        },
+
+        keypress: function (handler) {
+            return this.on("keypress", handler);
+        }
+    };
+
+    function frame(el) {
+        ns(".source .collapsible", el).toggle();
+    }
+
+    function expandCollapseButton(el) {
+        var frameId = el.getAttribute("data-frameId");
+        frame(document.getElementById(frameId));
+        if (el.innerText === "+") {
+            el.innerText = "-";
+        }
+        else {
+            el.innerText = "+";
+        }
+    }
+
+    function tab(el) {
+        var unselected = ns("#header .selected").removeClass("selected").attr("id");
+        var selected = ns("#" + el.id).addClass("selected").attr("id");
+
+        ns("#" + unselected + "page").hide();
+        ns("#" + selected + "page").show();
+    }
+
+    ns(".rawExceptionDetails").hide();
+    ns(".collapsible").hide();
+    ns(".page").hide();
+    ns("#stackpage").show();
+
+    ns(".expandCollapseButton")
+        .click(function () {
+            expandCollapseButton(this);
+        })
+        .keypress(function (e) {
+            if (e.which === 13) {
+                expandCollapseButton(this);
+            }
+        });
+
+    ns("#header li")
+        .click(function () {
+            tab(this);
+        })
+        .keypress(function (e) {
+            if (e.which === 13) {
+                tab(this);
+            }
+        });
+
+    ns(".showRawException")
+        .click(function () {
+            var exceptionDetailId = this.getAttribute("data-exceptionDetailId");
+            ns("#" + exceptionDetailId).toggle();
+        });
+})(window);

src/Microsoft.AspNetCore.Hosting/Startup/ExceptionPage/Views/ErrorPageModel.cs

@@ -0,0 +1,29 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System.Collections.Generic;
+using Microsoft.Extensions.StackTrace.Sources;
+
+namespace Microsoft.AspNetCore.Hosting.Views
+{
+    /// <summary>
+    /// Holds data to be displayed on the error page.
+    /// </summary>
+    internal class ErrorPageModel
+    {
+        /// <summary>
+        /// Detailed information about each exception in the stack.
+        /// </summary>
+        public IEnumerable<ExceptionDetails> ErrorDetails { get; set; }
+
+        public string RuntimeDisplayName { get; set; }
+
+        public string RuntimeArchitecture { get; set; }
+
+        public string ClrVersion { get; set; }
+
+        public string CurrentAssemblyVesion { get; set; }
+
+        public string OperatingSystemDescription { get; set; }
+    }
+}

src/Microsoft.AspNetCore.Hosting/Startup/StartupExceptionPage.cs

@@ -1,329 +0,0 @@
-// Copyright (c) .NET Foundation. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-using System;
-using System.Collections.Generic;
-using System.Diagnostics;
-using System.Globalization;
-using System.IO;
-using System.Linq;
-using System.Reflection;
-using System.Runtime.ExceptionServices;
-using System.Runtime.InteropServices;
-using System.Text;
-using System.Text.Encodings.Web;
-using Microsoft.Extensions.StackTrace.Sources;
-
-namespace Microsoft.AspNetCore.Hosting
-{
-    internal static class StartupExceptionPage
-    {
-        private static readonly string _errorPageFormatString = GetResourceString("GenericError.html", escapeBraces: true);
-        private static readonly string _errorMessageFormatString = GetResourceString("GenericError_Message.html");
-        private static readonly string _errorExceptionFormatString = GetResourceString("GenericError_Exception.html");
-        private static readonly string _errorFooterFormatString = GetResourceString("GenericError_Footer.html");
-
-        public static byte[] GenerateErrorHtml(bool showDetails, Exception exception)
-        {
-            // Build the message for each error
-            var builder = new StringBuilder();
-            var rawExceptionDetails = new StringBuilder();
-
-            if (!showDetails)
-            {
-                WriteMessage("An error occurred while starting the application.", builder);
-            }
-            else
-            {
-                Debug.Assert(exception != null);
-                var wasSourceCodeWrittenOntoPage = false;
-                var flattenedExceptions = FlattenAndReverseExceptionTree(exception);
-                foreach (var innerEx in flattenedExceptions)
-                {
-                    WriteException(innerEx, builder, ref wasSourceCodeWrittenOntoPage);
-                }
-
-                WriteRawExceptionDetails("Show raw exception details", exception.ToString(), rawExceptionDetails);
-            }
-
-            // Generate the footer
-            var footer = showDetails ? GenerateFooterEncoded() : null;
-
-            // And generate the full markup
-            return Encoding.UTF8.GetBytes(string.Format(CultureInfo.InvariantCulture, _errorPageFormatString, builder, rawExceptionDetails, footer));
-        }
-
-        private static string BuildCodeSnippetDiv(StackFrameInfo frameInfo)
-        {
-            var filename = frameInfo.FilePath;
-            if (!string.IsNullOrEmpty(filename))
-            {
-                int failingLineNumber = frameInfo.LineNumber;
-                if (failingLineNumber >= 1)
-                {
-                    var lines = GetFailingCallSiteInFile(filename, failingLineNumber);
-                    if (lines != null)
-                    {
-                        return @"<div class=""codeSnippet"">"
-                            + @"<div class=""filename""><code>" + HtmlEncodeAndReplaceLineBreaks(filename) + "</code></div>" + Environment.NewLine
-                            + string.Join(Environment.NewLine, lines) + "</div>" + Environment.NewLine;
-                    }
-                }
-            }
-
-            // fallback
-            return null;
-        }
-
-        private static string BuildLineForStackFrame(StackFrameInfo frameInfo)
-        {
-            var builder = new StringBuilder("<pre>");
-            var stackFrame = frameInfo.StackFrame;
-            var method = stackFrame.GetMethod();
-            var displayInfo = frameInfo.MethodDisplayInfo;
-
-            // Special case: no method available
-            if (method == null)
-            {
-                return null;
-            }
-
-            // First, write the type name
-            var type = method.DeclaringType;
-            if (type != null)
-            {
-                // Special-case ExceptionDispatchInfo.Throw()
-                if (type == typeof(ExceptionDispatchInfo) && method.Name == "Throw")
-                {
-                    return @"<pre><span class=""faded"">--- exception rethrown ---</span></pre>";
-                }
-
-                var typeName = displayInfo.DeclaringTypeName;
-                // Separate the namespace component from the type name so that we can format it differently.
-                if (!string.IsNullOrEmpty(typeName) && !string.IsNullOrEmpty(type.Namespace))
-                {
-                    builder.Append($@"<span class=""faded"">at {HtmlEncodeAndReplaceLineBreaks(type.Namespace)}</span>");
-                    typeName = typeName.Substring(type.Namespace.Length);
-                }
-
-                builder.Append(HtmlEncodeAndReplaceLineBreaks(typeName));
-            }
-
-            // Next, write the method signature
-            builder.Append(displayInfo.Name);
-
-            // Build method parameters
-            var methodParameters = "(" + string.Join(", ", displayInfo.Parameters) + ")";
-            builder.Append($@"<span class=""faded"">{HtmlEncodeAndReplaceLineBreaks(methodParameters)}</span>");
-
-            // Do we have source information for this frame?
-            if (stackFrame.GetILOffset() != -1)
-            {
-                var filename = frameInfo.FilePath;
-                if (!string.IsNullOrEmpty(filename))
-                {
-                    builder.AppendFormat(CultureInfo.InvariantCulture, " in {0}:line {1:D}", HtmlEncodeAndReplaceLineBreaks(filename), frameInfo.LineNumber);
-                }
-            }
-
-            // Finish
-            builder.Append("</pre>");
-            return builder.ToString();
-        }
-
-        private static string GetResourceString(string name, bool escapeBraces = false)
-        {
-            // '{' and '}' are special in CSS, so we use "[[[0]]]" instead for {0} (and so on).
-            var assembly = typeof(StartupExceptionPage).GetTypeInfo().Assembly;
-            var resourceName = assembly.GetName().Name + ".compiler.resources." + name;
-            var manifestStream = assembly.GetManifestResourceStream(resourceName);
-            var formatString = new StreamReader(manifestStream, Encoding.UTF8, detectEncodingFromByteOrderMarks: false).ReadToEnd();
-            if (escapeBraces)
-            {
-                formatString = formatString.Replace("{", "{{").Replace("}", "}}").Replace("[[[", "{").Replace("]]]", "}");
-            }
-
-            return formatString;
-        }
-
-        private static List<string> GetFailingCallSiteInFile(string filename, int failedLineNumber)
-        {
-            // We figure out the [first, last] range of lines to read from the file.
-            var firstLineNumber = failedLineNumber - 2;
-            firstLineNumber = Math.Max(1, firstLineNumber);
-            var lastLineNumber = failedLineNumber + 2;
-            lastLineNumber = Math.Max(lastLineNumber, failedLineNumber);
-
-            // Figure out how many characters lastLineNumber will take to print.
-            var lastLineNumberCharLength = lastLineNumber.ToString("D", CultureInfo.InvariantCulture).Length;
-
-            var errorSubContents = new List<string>();
-            var didReadFailingLine = false;
-
-            try
-            {
-                var thisLineNum = 0;
-                foreach (var line in File.ReadLines(filename))
-                {
-                    thisLineNum++;
-
-                    // Are we within the correct range?
-                    if (thisLineNum < firstLineNumber)
-                    {
-                        continue;
-                    }
-                    if (thisLineNum > lastLineNumber)
-                    {
-                        break;
-                    }
-
-                    var encodedLine = HtmlEncodeAndReplaceLineBreaks("Line "
-                        + thisLineNum.ToString("D", CultureInfo.InvariantCulture).PadLeft(lastLineNumberCharLength)
-                        + ":  "
-                        + line);
-
-                    if (thisLineNum == failedLineNumber)
-                    {
-                        didReadFailingLine = true;
-                        errorSubContents.Add(@"<div class=""line error""><code>" + encodedLine + "</code></div>");
-                    }
-                    else
-                    {
-                        errorSubContents.Add(@"<div class=""line""><code>" + encodedLine + "</code></div>");
-                    }
-                }
-            }
-            catch
-            {
-                // If there's an error for any reason, don't show source.
-                return null;
-            }
-
-            return (didReadFailingLine) ? errorSubContents : null;
-        }
-
-        private static string GenerateFooterEncoded()
-        {
-            var runtimeType = HtmlEncodeAndReplaceLineBreaks(Microsoft.Extensions.Internal.RuntimeEnvironment.RuntimeType);
-            var runtimeDisplayName = runtimeType == "CoreCLR" ? ".NET Core" : runtimeType == "CLR" ? ".NET Framework" : "Mono";
-#if NETSTANDARD1_3
-            var systemRuntimeAssembly = typeof(System.ComponentModel.DefaultValueAttribute).GetTypeInfo().Assembly;
-            var assemblyVersion = new AssemblyName(systemRuntimeAssembly.FullName).Version.ToString();
-            var clrVersion = HtmlEncodeAndReplaceLineBreaks(assemblyVersion);
-#else
-            var clrVersion = HtmlEncodeAndReplaceLineBreaks(Environment.Version.ToString());
-#endif
-            var runtimeArch = HtmlEncodeAndReplaceLineBreaks(RuntimeInformation.ProcessArchitecture.ToString());
-            var currentAssembly = typeof(StartupExceptionPage).GetTypeInfo().Assembly;
-            var currentAssemblyVersion = currentAssembly.GetCustomAttribute<AssemblyInformationalVersionAttribute>().InformationalVersion;
-            currentAssemblyVersion = HtmlEncodeAndReplaceLineBreaks(currentAssemblyVersion);
-
-            var osDescription = HtmlEncodeAndReplaceLineBreaks(RuntimeInformation.OSDescription);
-
-            return string.Format(CultureInfo.InvariantCulture, _errorFooterFormatString, runtimeDisplayName, runtimeArch, clrVersion,
-                currentAssemblyVersion, osDescription);
-        }
-
-        private static string HtmlEncodeAndReplaceLineBreaks(string input)
-        {
-            if (string.IsNullOrEmpty(input))
-            {
-                return string.Empty;
-            }
-
-            // Split on line breaks before passing it through the encoder.
-            // We use the static default encoder since we can't depend on DI in the error handling logic.
-            return string.Join("<br />" + Environment.NewLine,
-                input.Split(new[] { "\r\n" }, StringSplitOptions.None)
-                .SelectMany(s => s.Split(new[] { '\r', '\n' }, StringSplitOptions.None))
-                .Select(HtmlEncoder.Default.Encode));
-        }
-
-        private static void WriteException(Exception ex, StringBuilder builder, ref bool wasFailingCallSiteSourceWritten)
-        {
-            string inlineSourceDiv = null;
-
-            // First, build the stack trace
-            var firstStackFrame = true;
-            var stackTraceBuilder = new StringBuilder();
-            foreach (var frameInfo in StackTraceHelper.GetFrames(ex))
-            {
-                if (!firstStackFrame)
-                {
-                    stackTraceBuilder.Append("<br />");
-                }
-                firstStackFrame = false;
-                var thisFrameLine = BuildLineForStackFrame(frameInfo);
-                stackTraceBuilder.AppendLine(thisFrameLine);
-
-                // Try to include the source code in the error page if we can.
-                if (!wasFailingCallSiteSourceWritten && inlineSourceDiv == null)
-                {
-                    inlineSourceDiv = BuildCodeSnippetDiv(frameInfo);
-                    if (inlineSourceDiv != null)
-                    {
-                        wasFailingCallSiteSourceWritten = true;
-                    }
-                }
-            }
-
-            // Finally, build the rest of the <div>
-            builder.AppendFormat(CultureInfo.InvariantCulture, _errorExceptionFormatString,
-                HtmlEncodeAndReplaceLineBreaks(ex.GetType().FullName),
-                HtmlEncodeAndReplaceLineBreaks(ex.Message),
-                inlineSourceDiv,
-                stackTraceBuilder);
-        }
-
-        private static void WriteRawExceptionDetails(string linkText, string line, StringBuilder rawExceptionDetails)
-        {
-            rawExceptionDetails
-                .AppendLine("<div class=\"rawExceptionBlock\">")
-                .AppendFormat($"    <div><a href=\"#\" onclick=\"javascript: showRawException(); return false;\">{linkText}</a></div>")
-                .AppendLine()
-                .AppendLine("    <div id=\"rawException\">")
-                .Append("        <pre>");
-
-            rawExceptionDetails.AppendLine(line);
-
-            rawExceptionDetails
-                .AppendLine("</pre>")
-                .AppendLine("    </div>")
-                .AppendLine("</div>");
-        }
-
-        private static void WriteMessage(string message, StringBuilder builder)
-        {
-            // Build the <div>
-            builder.AppendFormat(CultureInfo.InvariantCulture, _errorMessageFormatString,
-                HtmlEncodeAndReplaceLineBreaks(message));
-        }
-
-        private static IEnumerable<Exception> FlattenAndReverseExceptionTree(Exception ex)
-        {
-            // ReflectionTypeLoadException is special because the details are in 
-            // the LoaderExceptions property
-            var typeLoadException = ex as ReflectionTypeLoadException;
-            if (typeLoadException != null)
-            {
-                var typeLoadExceptions = new List<Exception>();
-                foreach (var loadException in typeLoadException.LoaderExceptions)
-                {
-                    typeLoadExceptions.AddRange(FlattenAndReverseExceptionTree(loadException));
-                }
-
-                typeLoadExceptions.Add(ex);
-                return typeLoadExceptions;
-            }
-
-            var list = new List<Exception>();
-            while (ex != null)
-            {
-                list.Add(ex);
-                ex = ex.InnerException;
-            }
-            list.Reverse();
-            return list;
-        }
-    }
-}

src/Microsoft.AspNetCore.Hosting/project.json

@@ -24,13 +24,17 @@
     "Microsoft.AspNetCore.Hosting.Server.Abstractions": "1.1.0-*",
     "Microsoft.AspNetCore.Http": "1.1.0-*",
     "Microsoft.AspNetCore.Http.Extensions": "1.1.0-*",
-    "Microsoft.Extensions.FileProviders.Physical": "1.1.0-*",
-    "Microsoft.Extensions.Options": "1.1.0-*",
     "Microsoft.Extensions.Configuration": "1.1.0-*",
     "Microsoft.Extensions.Configuration.EnvironmentVariables": "1.1.0-*",
     "Microsoft.Extensions.DependencyInjection": "1.1.0-*",
+    "Microsoft.Extensions.FileProviders.Physical": "1.1.0-*",
     "Microsoft.Extensions.Logging": "1.1.0-*",
+    "Microsoft.Extensions.Options": "1.1.0-*",
     "Microsoft.Extensions.PlatformAbstractions": "1.1.0-*",
+    "Microsoft.Extensions.RazorViews.Sources": {
+      "type": "build",
+      "version": "1.1.0-*"
+    },
     "Microsoft.Extensions.RuntimeEnvironment.Sources": {
       "type": "build",
       "version": "1.1.0-*"
@@ -68,5 +72,8 @@
         "System.Reflection.Extensions": "4.0.1-*"
       }
     }
+  },
+  "tools": {
+    "RazorPageGenerator": "1.1.0-*"
   }
 }

test/Microsoft.AspNetCore.Hosting.Tests/WebHostBuilderTests.cs

@@ -82,7 +82,7 @@ namespace Microsoft.AspNetCore.Hosting
             using (host)
             {
                 host.Start();
-                await AssertResponseContains(server.RequestDelegate, "Message from the LoaderException</span>");
+                await AssertResponseContains(server.RequestDelegate, "Message from the LoaderException</div>");
             }
         }
 
@@ -481,20 +481,20 @@ namespace Microsoft.AspNetCore.Hosting
             var hostingEnv = host.Services.GetService<IHostingEnvironment>();
             Assert.Equal("Microsoft.AspNetCore.Hosting.Tests", hostingEnv.ApplicationName);
         }
-        
+
         [Fact]
         public void Configure_SupportsStaticMethodDelegate()
         {
             var host = new WebHostBuilder()
                 .UseServer(new TestServer())
-                .Configure(StaticConfigureMethod) 
+                .Configure(StaticConfigureMethod)
                 .Build();
 
             var hostingEnv = host.Services.GetService<IHostingEnvironment>();
             Assert.Equal("Microsoft.AspNetCore.Hosting.Tests", hostingEnv.ApplicationName);
         }
 
-        private static void StaticConfigureMethod(IApplicationBuilder app) 
+        private static void StaticConfigureMethod(IApplicationBuilder app)
         { }
 
         private IWebHostBuilder CreateWebHostBuilder()