Fix empty categories tree (fixes #400)

allure-generator/src/main/javascript/components/status-toggle/StatusToggleView.hbs

@@ -1,16 +1,14 @@
 <div class="{{b 'status-toggle' 'items'}}">
     {{t 'component.tree.filter'}}:
     {{#each statuses}}
-        {{#if count}}
-            <div class="{{b 'status-toggle' 'item'}}">
-            {{#if active}}
-                <span class="y-label y-label_status_{{status}}" data-status="{{status}}"
-                        data-tooltip="{{t 'component.statusToggle.hideCases' status=statusName}}">{{count}}</span>
-            {{else}}
-                <span class="n-label n-label_status_{{status}}" data-status="{{status}}"
-                        data-tooltip="{{t 'component.statusToggle.showCases' status=statusName}}">{{count}}</span>
-            {{/if}}
-            </div>
+        <div class="{{b 'status-toggle' 'item'}}">
+        {{#if active}}
+            <span class="y-label y-label_status_{{status}}" data-status="{{status}}"
+                    data-tooltip="{{t 'component.statusToggle.hideCases' status=statusName}}">{{count}}</span>
+        {{else}}
+            <span class="n-label n-label_status_{{status}}" data-status="{{status}}"
+                    data-tooltip="{{t 'component.statusToggle.showCases' status=statusName}}">{{count}}</span>
         {{/if}}
+        </div>
     {{/each}}
 </div>

allure-generator/src/main/javascript/components/tree/TreeView.js

@@ -93,7 +93,6 @@ class TreeView extends View {
         const showGroupInfo = settings.get('showGroupInfo');
         const shownCases = this.collection.testcases.length;
         const totalCases = this.collection.allTestcases.length;
-
         return {
             baseUrl: this.baseUrl,
             showGroupInfo: showGroupInfo,

allure-generator/src/main/javascript/data/tree/TreeCollection.js

@@ -18,11 +18,12 @@ export default class TreeCollection extends Collection {
     }
 
     parse({time, statistic, children}) {
-        this.allTestcases = this.getFlattenTestcases(children);
-        this.allNodes = children;
+        const items = children || [];
+        this.allTestcases = this.getFlattenTestcases(items);
+        this.allNodes = items;
         this.time = time;
         this.statistic = statistic;
-        return children;
+        return items;
     }
 
     applyFilterAndSorting(statuses, sortSettings) {

allure-plugin-api/src/main/java/io/qameta/allure/tree/AbstractTreeAggregator.java

@@ -5,6 +5,8 @@
 import io.qameta.allure.context.RandomUidContext;
 import io.qameta.allure.core.Configuration;
 import io.qameta.allure.core.LaunchResults;
+import io.qameta.allure.entity.GroupTime;
+import io.qameta.allure.entity.Statistic;
 import io.qameta.allure.entity.StatusDetails;
 import io.qameta.allure.entity.TestResult;
 
@@ -39,7 +41,11 @@ public void aggregate(final Configuration configuration,
 
     protected TreeData getData(final Supplier<String> uidGenerator,
                                final List<LaunchResults> launches) {
-        final TreeData tree = new TreeData();
+        final TreeData tree = new TreeData()
+                .withTime(new GroupTime())
+                .withStatistic(new Statistic())
+                .withChildren(new ArrayList<>());
+
         launches.stream()
                 .flatMap(launch -> launch.getResults().stream())
                 .forEach(result -> addResultToTree(uidGenerator, tree, result));