Retrieve source code for the entire stack trace

Provide the ability to extract the source code of the entire exception stack
trace, not just the frame raising the error. This improves debugging
capability of the error page, especially for framework-related errors.

8 files changed, 109 insertions, 69 deletions

diff --git a/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb b/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb
index 0ca1a87645..274f6f2f22 100644
--- a/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb
+++ b/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb
@@ -38,9 +38,7 @@ module ActionDispatch
         template = ActionView::Base.new([RESCUES_TEMPLATE_PATH],
           request: request,
           exception: wrapper.exception,
-          application_trace: wrapper.application_trace,
-          framework_trace: wrapper.framework_trace,
-          full_trace: wrapper.full_trace,
+          traces: traces_from_wrapper(wrapper),
           routes_inspector: routes_inspector(exception),
           source_extract: wrapper.source_extract,
           line_number: wrapper.line_number,
@@ -95,5 +93,36 @@ module ActionDispatch
         ActionDispatch::Routing::RoutesInspector.new(@routes_app.routes.routes)
       end
     end
+
+    # Augment the exception traces by providing ids for all unique stack frame
+    def traces_from_wrapper(wrapper)
+      application_trace = wrapper.application_trace
+      framework_trace = wrapper.framework_trace
+      full_trace = wrapper.full_trace
+
+      if application_trace && framework_trace
+        id_counter = 0
+
+        application_trace = application_trace.map do |trace|
+          prev = id_counter
+          id_counter += 1
+          { id: prev, trace: trace }
+        end
+
+        framework_trace = framework_trace.map do |trace|
+          prev = id_counter
+          id_counter += 1
+          { id: prev, trace: trace }
+        end
+
+        full_trace = application_trace + framework_trace
+      end
+
+      {
+        "Application Trace" => application_trace,
+        "Framework Trace" => framework_trace,
+        "Full Trace" => full_trace
+      }
+    end
   end
 end
diff --git a/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb b/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb
index 2326bb043a..b98b553c38 100644
--- a/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb
+++ b/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb
@@ -61,12 +61,15 @@ module ActionDispatch
     end
 
     def source_extract
-      if application_trace && trace = application_trace.first
-        file, line, _ = trace.split(":")
-        @file = file
-        @line_number = line.to_i
-        source_fragment(@file, @line_number)
-      end
+      exception.backtrace.map do |trace|
+        file, line = trace.split(":")
+        line_number = line.to_i
+        {
+          code: source_fragment(file, line_number),
+          file: file,
+          line_number: line_number
+        }
+      end if exception.backtrace
     end
 
     private
@@ -110,7 +113,7 @@ module ActionDispatch
     def expand_backtrace
       @exception.backtrace.unshift(
         @exception.to_s.split("\n")
-      ).flatten! 
+      ).flatten!
     end
   end
 end
diff --git a/actionpack/lib/action_dispatch/middleware/templates/rescues/_source.erb b/actionpack/lib/action_dispatch/middleware/templates/rescues/_source.erb
index 38429cb78e..51660a619b 100644
--- a/actionpack/lib/action_dispatch/middleware/templates/rescues/_source.erb
+++ b/actionpack/lib/action_dispatch/middleware/templates/rescues/_source.erb
@@ -1,25 +1,29 @@
 <% if @source_extract %>
-<div class="source">
-<div class="info">
-  Extracted source (around line <strong>#<%= @line_number %></strong>):
-</div>
-<div class="data">
-  <table cellpadding="0" cellspacing="0" class="lines">
-      <tr>
-        <td>
-          <pre class="line_numbers">
-            <% @source_extract.keys.each do |line_number| %>
+  <% @source_extract.each_with_index do |extract_source, index| %>
+    <% if extract_source[:code] %>
+      <div class="source <%="hidden" if index != 0%>" id="frame-source-<%=index%>">
+        <div class="info">
+          Extracted source (around line <strong>#<%= extract_source[:line_number] %></strong>):
+        </div>
+        <div class="data">
+          <table cellpadding="0" cellspacing="0" class="lines">
+            <tr>
+              <td>
+                <pre class="line_numbers">
+                  <% extract_source[:code].keys.each do |line_number| %>
 <span><%= line_number -%></span>
-            <% end %>
-          </pre>
-        </td>
+                  <% end %>
+                </pre>
+              </td>
 <td width="100%">
 <pre>
-<% @source_extract.each do |line, source| -%><div class="line<%= " active" if line == @line_number -%>"><%= source -%></div><% end -%>
+<% extract_source[:code].each do |line, source| -%><div class="line<%= " active" if line == extract_source[:line_number] -%>"><%= source -%></div><% end -%>
 </pre>
 </td>
-    </tr>
-  </table>
-</div>
-</div>
+            </tr>
+          </table>
+        </div>
+      </div>
+    <% end %>
+  <% end %>
 <% end %>
diff --git a/actionpack/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb b/actionpack/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb
index b181909bff..f62caf51d7 100644
--- a/actionpack/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb
+++ b/actionpack/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb
@@ -1,9 +1,4 @@
-<%
-   traces = { "Application Trace" => @application_trace,
-              "Framework Trace"   => @framework_trace,
-              "Full Trace"        => @full_trace }
-   names = traces.keys
-%>
+<% names = @traces.keys %>
 
 <p><code>Rails.root: <%= defined?(Rails) && Rails.respond_to?(:root) ? Rails.root : "unset" %></code></p>
 
@@ -16,9 +11,42 @@
     <a href="#" onclick="<%= hide.join %><%= show %>; return false;"><%= name %></a> <%= '|' unless names.last == name %>
   <% end %>
 
-  <% traces.each do |name, trace| %>
+  <% @traces.each do |name, trace| %>
     <div id="<%= name.gsub(/\s/, '-') %>" style="display: <%= (name == "Application Trace") ? 'block' : 'none' %>;">
-      <pre><code><%= trace.join "\n" %></code></pre>
+      <pre><code><% trace.each do |frame| %><a class="trace-frames" data-frame-id="<%= frame[:id] %>" href="#"><%= frame[:trace] %></a><br><% end %></code></pre>
     </div>
   <% end %>
+
+  <script type="text/javascript">
+    var traceFrames = document.getElementsByClassName('trace-frames');
+    var selectedFrame, currentSource = document.getElementById('frame-source-0');
+
+    // Add click listeners for all stack frames
+    for (var i = 0; i < traceFrames.length; i++) {
+      traceFrames[i].addEventListener('click', function(e) {
+        e.preventDefault();
+        var target = e.target;
+        var frame_id = target.dataset.frameId;
+
+        if (selectedFrame) {
+          selectedFrame.className = selectedFrame.className.replace("selected", "");
+        }
+
+        target.className += " selected";
+        selectedFrame = target;
+
+        // Change the extracted source code
+        changeSourceExtract(frame_id);
+      });
+
+      function changeSourceExtract(frame_id) {
+        var el = document.getElementById('frame-source-' + frame_id);
+        if (currentSource && el) {
+          currentSource.className += " hidden";
+          el.className = el.className.replace(" hidden", "");
+          currentSource = el;
+        }
+      }
+    }
+  </script>
 </div>
diff --git a/actionpack/lib/action_dispatch/middleware/templates/rescues/_trace.text.erb b/actionpack/lib/action_dispatch/middleware/templates/rescues/_trace.text.erb
index d4af5c9b06..36b01bf952 100644
--- a/actionpack/lib/action_dispatch/middleware/templates/rescues/_trace.text.erb
+++ b/actionpack/lib/action_dispatch/middleware/templates/rescues/_trace.text.erb
@@ -1,15 +1,9 @@
-<%
-  traces = { "Application Trace" => @application_trace,
-             "Framework Trace"   => @framework_trace,
-             "Full Trace"        => @full_trace }
-%>
-
 Rails.root: <%= defined?(Rails) && Rails.respond_to?(:root) ? Rails.root : "unset" %>
 
-<% traces.each do |name, trace| %>
+<% @traces.each do |name, trace| %>
 <% if trace.any? %>
 <%= name %>
-<%= trace.join("\n") %>
+<%= trace.map(&:trace).join("\n") %>
 
 <% end %>
 <% end %>
diff --git a/actionpack/lib/action_dispatch/middleware/templates/rescues/layout.erb b/actionpack/lib/action_dispatch/middleware/templates/rescues/layout.erb
index bc5d03dc10..e0509f56f4 100644
--- a/actionpack/lib/action_dispatch/middleware/templates/rescues/layout.erb
+++ b/actionpack/lib/action_dispatch/middleware/templates/rescues/layout.erb
@@ -116,9 +116,15 @@
       background-color: #FFCCCC;
     }
 
+    .hidden {
+      display: none;
+    }
+
     a { color: #980905; }
     a:visited { color: #666; }
+    a.trace-frames { color: #666; }
     a:hover { color: #C52F24; }
+    a.trace-frames.selected { color: #C52F24 }
 
     <%= yield :style %>
   </style>
diff --git a/actionpack/lib/action_dispatch/middleware/templates/rescues/template_error.html.erb b/actionpack/lib/action_dispatch/middleware/templates/rescues/template_error.html.erb
index 027a0f5b3e..c1e8b6cae3 100644
--- a/actionpack/lib/action_dispatch/middleware/templates/rescues/template_error.html.erb
+++ b/actionpack/lib/action_dispatch/middleware/templates/rescues/template_error.html.erb
@@ -1,4 +1,3 @@
-<% @source_extract = @exception.source_extract(0, :html) %>
 <header>
   <h1>
     <%= @exception.original_exception.class.to_s %> in
@@ -12,29 +11,7 @@
   </p>
   <pre><code><%= h @exception.message %></code></pre>
 
-  <div class="source">
-    <div class="info">
-      <p>Extracted source (around line <strong>#<%= @exception.line_number %></strong>):</p>
-    </div>
-    <div class="data">
-    <table cellpadding="0" cellspacing="0" class="lines">
-      <tr>
-        <td>
-          <pre class="line_numbers">
-            <% @source_extract.keys.each do |line_number| %>
-<span><%= line_number -%></span>
-            <% end %>
-          </pre>
-        </td>
-<td width="100%">
-<pre>
-<% @source_extract.each do |line, source| -%><div class="line<%= " active" if line == @exception.line_number -%>"><%= source -%></div><% end -%>
-</pre>
-</td>
-    </tr>
-  </table>
-</div>
-</div>
+  <%= render template: "rescues/_source" %>
 
   <p><%= @exception.sub_template_message %></p>
 
diff --git a/actionpack/lib/action_dispatch/middleware/templates/rescues/template_error.text.erb b/actionpack/lib/action_dispatch/middleware/templates/rescues/template_error.text.erb
index 5da21d9784..77bcd26726 100644
--- a/actionpack/lib/action_dispatch/middleware/templates/rescues/template_error.text.erb
+++ b/actionpack/lib/action_dispatch/middleware/templates/rescues/template_error.text.erb
@@ -1,4 +1,3 @@
-<% @source_extract = @exception.source_extract(0, :html) %>
 <%= @exception.original_exception.class.to_s %> in <%= @request.parameters["controller"].camelize if @request.parameters["controller"] %>#<%= @request.parameters["action"] %>
 
 Showing <%= @exception.file_name %> where line #<%= @exception.line_number %> raised: