Add support for generating Structurizr legend.

Resolves yuzutech#1686.

ci/tests/smoke.js

@@ -33,6 +33,7 @@ const tests = [
   { engine: 'excalidraw', file: 'venn.excalidraw', options: {}, outputFormat: ['svg'] },
   { engine: 'pikchr', file: 'sqlite-architecture.pikchr', options: {}, outputFormat: ['svg'] },
   { engine: 'structurizr', file: 'gettingstarted.structurizr', options: {}, outputFormat: ['svg'] },
+  { engine: 'structurizr', file: 'gettingstarted.structurizr', options: { output: 'legend' }, outputFormat: ['svg'] },
   { engine: 'diagramsnet', file: 'diagramsnet-infography.xml', options: {}, outputFormat: ['svg', 'png'] },
   { engine: 'diagramsnet', file: 'diagramsnet-mindmap.xml', options: {}, outputFormat: ['svg', 'png'] },
   { engine: 'diagramsnet', file: 'diagramsnet-network.xml', options: {}, outputFormat: ['svg', 'png'] },

docs/modules/setup/pages/diagram-options.adoc

@@ -200,6 +200,13 @@ empty string ("")
 |_string_
 |Key of the view (if the workspace contains more than one view)
 
+|output
+|_string_
+
+- `diagram`
+- `legend`
+|Select the output for the specified view.
+
 |===
 
 == Svgbob

server/src/main/java/io/kroki/server/service/Structurizr.java

@@ -132,7 +132,22 @@ static byte[] convert(String source, FileFormat fileFormat, PlantumlCommand plan
       } else {
         throw new BadRequestException("View type is not supported: " + selectedView.getClass().getSimpleName() + ", must be a DynamicView, DeploymentView, ComponentView, ContainerView, SystemContextView or SystemLandscapeView.");
       }
-      return plantumlCommand.convert(diagram.getDefinition(), fileFormat, new JsonObject());
+
+      String outputOption = options.getString("output");
+      if (outputOption != null) {
+        outputOption = outputOption.trim();
+      }
+
+      String diagramPlantUML;
+      if (outputOption == null || outputOption.equals("diagram")) {
+        diagramPlantUML = diagram.getDefinition();
+      } else if (outputOption.equals("legend")) {
+        diagramPlantUML = diagram.getLegend().getDefinition();
+      } else {
+        throw new BadRequestException("Unknown output option: " + outputOption);
+      }
+
+      return plantumlCommand.convert(diagramPlantUML, fileFormat, new JsonObject());
     } catch (StructurizrDslParserException e) {
       String cause = e.getMessage();
       final String message;

server/src/test/java/io/kroki/server/service/StructurizrServiceTest.java

@@ -15,6 +15,8 @@
 import org.junit.jupiter.api.condition.EnabledOnOs;
 import org.junit.jupiter.api.condition.OS;
 import org.junit.jupiter.api.extension.ExtendWith;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -50,12 +52,19 @@ static void prepare(VertxTestContext context, Vertx vertx) throws InterruptedExc
     });
   }
 
-  @Test
-  public void should_convert_getting_started_example() throws IOException, InterruptedException {
+  @ParameterizedTest
+  @ValueSource(strings = {"diagram", ""})
+  public void should_convert_getting_started_example(String output) throws IOException, InterruptedException {
     if (Files.isExecutable(Paths.get("/usr/bin/dot"))) {
       String source = read("./gettingstarted.structurizr");
       String expected = read("./gettingstarted.expected.svg");
-      byte[] result = Structurizr.convert(source, FileFormat.SVG, plantumlCommand, new StructurizrPlantUMLExporter(), new JsonObject());
+
+      JsonObject options = new JsonObject();
+      if (!output.isEmpty()) {
+        options.put("output", output);
+      }
+
+      byte[] result = Structurizr.convert(source, FileFormat.SVG, plantumlCommand, new StructurizrPlantUMLExporter(), options);
       assertThat(stripComments(new String(result))).isEqualToIgnoringNewLines(expected);
     } else {
       logger.info("/usr/bin/dot not found, skipping test.");
@@ -90,6 +99,21 @@ public void should_convert_bigbank_example_systemcontext_view() throws IOExcepti
     }
   }
 
+  @Test
+  public void should_convert_bigbank_example_systemcontext_legend() throws IOException, InterruptedException {
+    if (Files.isExecutable(Paths.get("/usr/bin/dot"))) {
+      String source = read("./bigbank.structurizr");
+      String expected = read("./bigbank.systemcontext.legend.expected.svg");
+      JsonObject options = new JsonObject();
+      options.put("view-key", "SystemContext");
+      options.put("output", "legend");
+      byte[] result = Structurizr.convert(source, FileFormat.SVG, plantumlCommand, new StructurizrPlantUMLExporter(), options);
+      assertThat(stripComments(new String(result))).isEqualToIgnoringNewLines(expected);
+    } else {
+      logger.info("/usr/bin/dot not found, skipping test.");
+    }
+  }
+
   @Test
   public void should_convert_aws_example() throws IOException, InterruptedException {
     if (Files.isExecutable(Paths.get("/usr/bin/dot"))) {
@@ -134,6 +158,20 @@ public void should_throw_exception_when_script_directive_used() throws IOExcepti
       .hasMessageStartingWith("Unable to parse the Structurizr DSL. Error running inline script, caused by java.lang.RuntimeException: Could not load a scripting engine for extension \"kts\" at line 5");
   }
 
+  @Test
+  public void should_throw_exception_when_unknown_output_specified() throws IOException {
+    String source = read("./bigbank.structurizr");
+
+    JsonObject options = new JsonObject();
+    options.put("output", "invalid");
+
+    assertThatThrownBy(() -> {
+      Structurizr.convert(source, FileFormat.SVG, plantumlCommand, new StructurizrPlantUMLExporter(), options);
+    })
+      .isInstanceOf(BadRequestException.class)
+      .hasMessageStartingWith("Unknown output option: invalid");
+  }
+
   @Test
   public void should_preserve_styles_defined_in_workspace_while_applying_theme() throws IOException, InterruptedException {
     String source = read("./workspace-style-with-theme.structurizr");