Fixes an issue when nested groups are configured, but groups are not nested.

Author: simonbrowndotje

README.md

@@ -25,9 +25,10 @@ Once the layout has been applied, you can upload your workspace to the Structuri
 
 ## Changelog
 
-### 1.8.1 (unreleased)
+### 1.8.1 (13th March 2023)
 
 - Fixes warning about clusters with the same name.
+- Fixes an issue when nested groups are configured, but groups are not nested.
 
 ### 1.8.0 (12th March 2023)
 

src/main/java/com/structurizr/graphviz/DotFileWriter.java

@@ -163,8 +163,10 @@ void write(ContainerView view) throws Exception {
                 softwareSystems.add((SoftwareSystem)elementView.getElement().getParent());
             }
         }
+        List<SoftwareSystem> sortedSoftwareSystems = new ArrayList<>(softwareSystems);
+        sortedSoftwareSystems.sort(Comparator.comparing(Element::getId));
 
-        for (SoftwareSystem softwareSystem : softwareSystems) {
+        for (SoftwareSystem softwareSystem : sortedSoftwareSystems) {
             fileWriter.write(String.format(locale, "  subgraph cluster_%s {\n", softwareSystem.getId()));
             fileWriter.write("    margin=" + CLUSTER_INTERNAL_MARGIN + "\n");
 
@@ -202,8 +204,10 @@ void write(ComponentView view) throws Exception {
                 containers.add((Container)elementView.getElement().getParent());
             }
         }
+        List<Container> sortedContainers = new ArrayList<>(containers);
+        sortedContainers.sort(Comparator.comparing(Element::getId));
 
-        for (Container container : containers) {
+        for (Container container : sortedContainers) {
             fileWriter.write(String.format(locale, "  subgraph cluster_%s {\n", container.getId()));
             fileWriter.write("    margin=" + CLUSTER_INTERNAL_MARGIN + "\n");
 
@@ -378,7 +382,7 @@ private void writeElements(ModelView view, String padding, Set<GroupableElement>
                     } else if (groupCount == contextCount) {
                         // moved from a/b to a/c
                         // - close off previous subgraph
-                        if (groupCount > 1) {
+                        if (context.length() > 0) {
                             writer.write(padding + "}\n");
                         }
                     } else {

src/test/java/com/structurizr/graphviz/DotFileWriterTests.java

@@ -536,4 +536,57 @@ public void test_writeComponentViewWithGroupedElements() throws Exception {
                 "}", content);
     }
 
+    @Test
+    public void test_writeContainerViewWithGroupedElements_WithAndWithoutAGroupSeparator() throws Exception {
+        Workspace workspace = new Workspace("Name", "");
+        SoftwareSystem softwareSystem = workspace.getModel().addSoftwareSystem("Software System", "");
+        Container container1 = softwareSystem.addContainer("Container 1");
+        container1.setGroup("Group 1");
+        Container container2 = softwareSystem.addContainer("Container 2");
+        container2.setGroup("Group 2");
+
+        ContainerView view = workspace.getViews().createContainerView(softwareSystem, "Containers", "");
+        view.addAllElements();
+
+        DotFileWriter dotFileWriter = new DotFileWriter(PATH, RankDirection.TopBottom, 300, 300);
+        dotFileWriter.write(view);
+
+        File file = new File(PATH, "Containers.dot");
+        assertTrue(file.exists());
+
+        String expectedResult = "digraph {\n" +
+                "  compound=true\n" +
+                "  graph [splines=polyline,rankdir=TB,ranksep=1.0,nodesep=1.0,fontsize=5]\n" +
+                "  node [shape=box,fontsize=5]\n" +
+                "  edge []\n" +
+                "\n" +
+                "  subgraph cluster_1 {\n" +
+                "    margin=25\n" +
+                "    subgraph cluster_group_1 {\n" +
+                "      margin=25\n" +
+                "      2 [width=1.500000,height=1.000000,fixedsize=true,id=2,label=\"2: Container 1\"]\n" +
+                "    }\n" +
+                "    subgraph cluster_group_2 {\n" +
+                "      margin=25\n" +
+                "      3 [width=1.500000,height=1.000000,fixedsize=true,id=3,label=\"3: Container 2\"]\n" +
+                "    }\n" +
+                "  }\n" +
+                "\n" +
+                "}";
+
+        String content = new String(Files.readAllBytes(file.toPath()));
+        assertEquals(expectedResult, content);
+
+        // this should be the same
+        workspace.getModel().addProperty("structurizr.groupSeparator", "/");
+        dotFileWriter = new DotFileWriter(PATH, RankDirection.TopBottom, 300, 300);
+        dotFileWriter.write(view);
+
+        file = new File(PATH, "Containers.dot");
+        assertTrue(file.exists());
+
+        content = new String(Files.readAllBytes(file.toPath()));
+        assertEquals(expectedResult, content);
+    }
+
 }