Show friendly message when stage has no data

app/assets/stylesheets/pages/cycle_analytics.scss

@@ -352,4 +352,23 @@
       } 
     }
   }
+
+  .empty-stage {
+    text-align: center;
+    width: 75%;
+    margin: 0 auto;
+    padding-top: 130px;
+    color: $gl-text-color-light;
+
+    .icon-no-data {
+      height: 36px;
+      width: 78px;
+      display: inline-block;
+      margin-bottom: 20px;
+    }
+
+    h4 {
+      color: $gl-text-color;
+    }
+  }
 }

app/views/projects/cycle_analytics/_empty_stage.html.haml

+.empty-stage-container
+  .empty-stage
+    .icon-no-data
+      = render "shared/icons/icon_no_data.svg"
+    %h4 We don’t have enough data to show this stage.
+    %p
+      The test phase measures the median time to run the entire pipeline for that project.
+      It’s related to the time GitLab CI takes to run every job for the commits pushed
+      to that merge request defined in the previous stage.
+      Learn more about the
+      %a{ :href => "https://docs.gitlab.com/ce/user/project/cycle_analytics.html" }
+        expected workflow and calculations.

app/views/projects/cycle_analytics/show.html.haml

@@ -90,6 +90,6 @@
           %template{ "v-if" => "isLoadingStage" }
             = icon("spinner spin", "v-show" => "isLoadingStage")
           %template{ "v-if" => "isEmptyStage" }
-            %p No results
+            = render partial: "empty_stage"
           %template{ "v-if" => "state.items.length && !isLoadingStage && !isEmptyStage" }
             %component{ ":is" => "currentStage.component", ":stage" => "currentStage", ":items" => "state.items" }

app/views/shared/icons/_icon_no_data.svg

+<svg xmlns="http://www.w3.org/2000/svg" viewBox="211 0 78 36" xmlns:xlink="http://www.w3.org/1999/xlink">
+  <defs>
+    <circle id="a" cx="5" cy="31" r="5"/>
+    <mask id="e" width="10" height="10" x="0" y="0" fill="#fff">
+      <use xlink:href="#a"/>
+    </mask>
+    <circle id="b" cx="29" cy="14" r="5"/>
+    <mask id="f" width="10" height="10" x="0" y="0" fill="#fff">
+      <use xlink:href="#b"/>
+    </mask>
+    <circle id="c" cx="53" cy="24" r="5"/>
+    <mask id="g" width="10" height="10" x="0" y="0" fill="#fff">
+      <use xlink:href="#c"/>
+    </mask>
+    <circle id="d" cx="73" cy="5" r="5"/>
+    <mask id="h" width="10" height="10" x="0" y="0" fill="#fff">
+      <use xlink:href="#d"/>
+    </mask>
+  </defs>
+  <g fill="none" fill-rule="evenodd" transform="translate(211)">
+    <path stroke="#B5A7DD" stroke-width="2" d="M5 31l24-17 26 10L73 5" stroke-linecap="round" stroke-dasharray="3 6"/>
+    <use fill="#FFF" stroke="#6B4FBB" stroke-width="6" mask="url(#e)" xlink:href="#a"/>
+    <use fill="#FFF" stroke="#6B4FBB" stroke-width="6" mask="url(#f)" xlink:href="#b"/>
+    <use fill="#FFF" stroke="#B5A7DD" stroke-width="6" mask="url(#g)" xlink:href="#c"/>
+    <use fill="#FFF" stroke="#B5A7DD" stroke-width="6" mask="url(#h)" xlink:href="#d"/>
+  </g>
+</svg>