Remove unconditional placeholder from dartdoc page rendering. (#8465)

Author: isoos

app/lib/dartdoc/dartdoc_page.dart

@@ -254,9 +254,6 @@ extension DartDocPageRender on DartDocPage {
             ],
           ),
           _left,
-          // TODO: remove this after all runtimes are rendered with dartdoc >=8.0.0
-          if (!left.contains('dartdoc-sidebar-left-content'))
-            d.div(id: 'dartdoc-sidebar-left-content', text: ''),
         ],
       );
 

app/test/dartdoc/dartdoc_page_test.dart

@@ -224,13 +224,6 @@ void main() {
               renderedFirstBreadcrumbs.remove();
             }
 
-            // removing unconditional placeholder
-            renderedXmlDoc.descendantElements
-                .firstWhereOrNull((e) =>
-                    e.localName == 'div' &&
-                    e.getAttribute('id') == 'dartdoc-sidebar-left-content')
-                ?.remove();
-
             // main content section -> div
             final fileMainContentDiv = fileXmlRoot.descendantElements
                 .firstWhere(

app/test/task/testdata/goldens/documentation/oxygen/1.0.0/index.html

@@ -85,7 +85,6 @@ <h5 class="hidden-xs">
             <a href="oxygen/">oxygen</a>
           </li>
         </ol>
-        <div id="dartdoc-sidebar-left-content"></div>
       </div>
       <div id="dartdoc-sidebar-right" class="sidebar sidebar-offcanvas-right"></div>
     </main>

app/test/task/testdata/goldens/documentation/oxygen/1.0.0/oxygen/index.html

@@ -121,7 +121,6 @@ <h5>
             <a href="../oxygen/">oxygen</a>
           </li>
         </ol>
-        <div id="dartdoc-sidebar-left-content"></div>
       </div>
       <div id="dartdoc-sidebar-right" class="sidebar sidebar-offcanvas-right">
         <h5>oxygen library</h5>

app/test/task/testdata/goldens/documentation/oxygen/2.0.0/index.html

@@ -85,7 +85,6 @@ <h5 class="hidden-xs">
             <a href="oxygen/">oxygen</a>
           </li>
         </ol>
-        <div id="dartdoc-sidebar-left-content"></div>
       </div>
       <div id="dartdoc-sidebar-right" class="sidebar sidebar-offcanvas-right"></div>
     </main>

app/test/task/testdata/goldens/documentation/oxygen/2.0.0/oxygen/index.html

@@ -121,7 +121,6 @@ <h5>
             <a href="../oxygen/">oxygen</a>
           </li>
         </ol>
-        <div id="dartdoc-sidebar-left-content"></div>
       </div>
       <div id="dartdoc-sidebar-right" class="sidebar sidebar-offcanvas-right">
         <h5>oxygen library</h5>

app/test/task/testdata/goldens/documentation/oxygen/latest/index.html

@@ -83,7 +83,6 @@ <h5 class="hidden-xs">
             <a href="oxygen/">oxygen</a>
           </li>
         </ol>
-        <div id="dartdoc-sidebar-left-content"></div>
       </div>
       <div id="dartdoc-sidebar-right" class="sidebar sidebar-offcanvas-right"></div>
     </main>

app/test/task/testdata/goldens/documentation/oxygen/latest/oxygen/index.html

@@ -119,7 +119,6 @@ <h5>
             <a href="../oxygen/">oxygen</a>
           </li>
         </ol>
-        <div id="dartdoc-sidebar-left-content"></div>
       </div>
       <div id="dartdoc-sidebar-right" class="sidebar sidebar-offcanvas-right">
         <h5>oxygen library</h5>