GH-638 - Create aggregating Asciidoc document including all files generated

spring-modulith-docs/src/main/java/org/springframework/modulith/docs/Asciidoctor.java

@@ -367,4 +367,19 @@ public String renderBeanReferences(ApplicationModule module) {
 
 		return bullets.isBlank() ? "None" : bullets;
 	}
+
+	public String renderHeadline(int i, String modules) {
+
+		return "=".repeat(i) + " " + modules + System.lineSeparator();
+	}
+
+	public String renderPlantUmlInclude(String componentsFilename) {
+
+		return "plantuml::" + componentsFilename + "[]" + System.lineSeparator();
+	}
+
+	public String renderGeneralInclude(String componentsFilename) {
+
+		return "include::" + componentsFilename + "[]" + System.lineSeparator();
+	}
 }

spring-modulith-docs/src/main/java/org/springframework/modulith/docs/Documenter.java

@@ -184,8 +184,89 @@ public Documenter writeDocumentation() {
 	public Documenter writeDocumentation(DiagramOptions options, CanvasOptions canvasOptions) {
 
 		return writeModulesAsPlantUml(options)
-				.writeIndividualModulesAsPlantUml(options) //
-				.writeModuleCanvases(canvasOptions);
+				.writeIndividualModulesAsPlantUml(options)
+				.writeModuleCanvases(canvasOptions)
+				.writeAggregatingDocument(options, canvasOptions);
+	}
+
+	/**
+	 * Writes aggregating document called 'all-docs.adoc' that includes any existing component diagrams and canvases.
+	 * using {@link DiagramOptions#defaults()} and {@link CanvasOptions#defaults()}.
+	 *
+	 * @return the current instance, will never be {@literal null}.
+	 */
+	public Documenter writeAggregatingDocument(){
+
+		return writeAggregatingDocument(DiagramOptions.defaults(), CanvasOptions.defaults());
+	}
+
+	/**
+	 * Writes aggregating document called 'all-docs.adoc' that includes any existing component diagrams and canvases.
+	 *
+	 * @param options must not be {@literal null}.
+	 * @param canvasOptions must not be {@literal null}.
+	 * @return the current instance, will never be {@literal null}.
+	 */
+	public Documenter writeAggregatingDocument(DiagramOptions options, CanvasOptions canvasOptions){
+
+		Assert.notNull(options, "DiagramOptions must not be null!");
+		Assert.notNull(canvasOptions, "CanvasOptions must not be null!");
+
+		var asciidoctor = Asciidoctor.withJavadocBase(modules, canvasOptions.getApiBase());
+		var outputFolder = new OutputFolder(this.outputFolder);
+
+		// Get file name for module overview diagram
+		var componentsFilename = options.getTargetFileName().orElse(DEFAULT_COMPONENTS_FILE);
+		var componentsDoc = new StringBuilder();
+
+		if (outputFolder.contains(componentsFilename)) {
+			componentsDoc.append(asciidoctor.renderHeadline(2, modules.getSystemName().orElse("Modules")))
+					.append(asciidoctor.renderPlantUmlInclude(componentsFilename))
+					.append(System.lineSeparator());
+		}
+
+		// Get file names for individual module diagrams and canvases
+		var moduleDocs = modules.stream().map(it -> {
+
+			// Get diagram file name, e.g. module-inventory.puml
+			var fileNamePattern = options.getTargetFileName().orElse(DEFAULT_MODULE_COMPONENTS_FILE);
+			Assert.isTrue(fileNamePattern.contains("%s"), () -> String.format(INVALID_FILE_NAME_PATTERN, fileNamePattern));
+			var filename = String.format(fileNamePattern, it.getName());
+
+			// Get canvas file name, e.g. module-inventory.adoc
+			var canvasFilename = canvasOptions.getTargetFileName(it.getName());
+
+			// Generate output, e.g.:
+			/*
+			== Inventory
+			plantuml::module-inventory.puml[]
+			include::module-inventory.adoc[]
+			 */
+			var content = new StringBuilder();
+			content.append((outputFolder.contains(filename) ? asciidoctor.renderPlantUmlInclude(filename) : ""))
+					.append((outputFolder.contains(canvasFilename) ? asciidoctor.renderGeneralInclude(canvasFilename) : ""));
+			if (!content.isEmpty()) {
+				content.insert(0, asciidoctor.renderHeadline(2, it.getDisplayName()))
+						.append(System.lineSeparator());
+			}
+			return content.toString();
+
+		}).collect(Collectors.joining());
+
+		var allDocs = componentsDoc.append(moduleDocs).toString();
+
+		// Write file to all-docs.adoc
+		if (!allDocs.isBlank()) {
+			Path file = recreateFile("all-docs.adoc");
+
+			try (Writer writer = new FileWriter(file.toFile())) {
+				writer.write(allDocs);
+			} catch (IOException o_O) {
+				throw new RuntimeException(o_O);
+			}
+		}
+
+		return this;
 	}
 
 	/**
@@ -1177,4 +1258,17 @@ protected void startContainerBoundary(ModelView view, Container container, Inden
 		@Override
 		protected void endContainerBoundary(ModelView view, IndentingWriter writer) {};
 	};
+
+	private static class OutputFolder {
+
+		private final String path;
+
+        OutputFolder(String path) {
+            this.path = path;
+        }
+
+		boolean contains(String filename) {
+			return Files.exists(Paths.get(path, filename));
+		}
+    }
 }

spring-modulith-integration-test/src/test/java/org/springframework/modulith/docs/DocumenterTest.java

@@ -24,6 +24,7 @@
 import java.nio.file.Paths;
 import java.util.Comparator;
 import java.util.Optional;
+import java.util.stream.Stream;
 
 import org.junit.jupiter.api.Test;
 import org.springframework.modulith.core.ApplicationModule;
@@ -86,10 +87,78 @@ void customizesOutputLocation() throws IOException {
 
 		} finally {
 
-			Files.walk(path)
-					.sorted(Comparator.reverseOrder())
-					.map(Path::toFile)
-					.forEach(File::delete);
+			deleteDirectory(path);
 		}
 	}
+
+	@Test // GH-638
+	void writesAggregatingDocumentOnlyIfOtherDocsExist() throws IOException {
+
+		String customOutputFolder = "build/spring-modulith";
+		Path path = Paths.get(customOutputFolder);
+
+		Documenter documenter = new Documenter(ApplicationModules.of(Application.class), customOutputFolder);
+
+		try {
+
+			// all-docs.adoc should be created
+			documenter.writeDocumentation();
+
+			// Count files
+			long actualFiles;
+			try (Stream<Path> stream = Files.walk(path)) {
+				actualFiles = stream.filter(Files::isRegularFile).count();
+			}
+			// Expect 2 files per module plus components diagram and all-docs.adoc
+			long expectedFiles = (documenter.getModules().stream().count() * 2) + 2;
+			assertThat(actualFiles).isEqualTo(expectedFiles);
+
+			Optional<Path> optionalPath = Files.walk(path)
+					.filter(p -> p.getFileName().toString().equals("all-docs.adoc"))
+					.findFirst();
+			assertThat(optionalPath.isPresent());
+
+			// Count non-blank lines in all-docs.adoc
+			long actualLines;
+			try (Stream<String> lines = Files.lines(optionalPath.get())) {
+				actualLines = lines.filter(line -> !line.trim().isEmpty())
+						.count();
+			}
+			// Expect 3 lines per module and 2 lines for components
+			long expectedLines = (documenter.getModules().stream().count() * 3) + 2;
+			assertThat(actualLines).isEqualTo(expectedLines);
+
+			// all-docs.adoc should not be created
+			deleteDirectoryContents(path);
+
+			documenter.writeAggregatingDocument();
+
+			optionalPath = Files.walk(path)
+					.filter(p -> p.getFileName().toString().equals("all-docs.adoc"))
+					.findFirst();
+			assertThat(optionalPath.isEmpty());
+
+		} finally {
+
+			deleteDirectory(path);
+		}
+	}
+
+	private static void deleteDirectoryContents(Path path) throws IOException {
+
+		if (Files.exists(path) && Files.isDirectory(path)) {
+			try (Stream<Path> walk = Files.walk(path)) {
+				walk.sorted(Comparator.reverseOrder())
+						.filter(p -> !p.equals(path)) // Ensure we don't delete the directory itself
+						.map(Path::toFile)
+						.forEach(File::delete);
+			}
+		}
+	}
+
+	private static void deleteDirectory(Path path) throws IOException {
+
+		deleteDirectoryContents(path);
+		Files.deleteIfExists(path);
+	}
 }

src/docs/antora/modules/ROOT/pages/documentation.adoc

@@ -7,6 +7,8 @@ Spring Modulith's `Documenter` abstraction can produce two different kinds of sn
 * C4 and UML component diagrams describing the relationships between the individual application modules
 * A so-called __Application Module Canvas__, a tabular overview about the module and the most relevant elements in those (Spring beans, aggregate roots, events published and listened to as well as configuration properties).
 
+Additionally, `Documenter` can produce an aggregating Asciidoc file that includes all existing component diagrams and canvases.
+
 [[component-diagrams]]
 == Generating Application Module Component diagrams
 
@@ -302,3 +304,46 @@ This will detect component stereotypes defined by https://github.com/xmolecules/
 * __Application events listened to by the module__ -- Derived from methods annotated with Spring's `@EventListener`, `@TransactionalEventListener`, jMolecules' `@DomainEventHandler` or beans implementing `ApplicationListener`.
 * __Configuration properties__ -- Spring Boot Configuration properties exposed by the application module.
 Requires the usage of the `spring-boot-configuration-processor` artifact to extract the metadata attached to the properties.
+
+[[aggregating-document]]
+== Generating an Aggregating Document
+
+The aggregating document can be generated by calling `Documenter.writeAggregatingDocument()`:
+
+.Generating an aggregating document using `Documenter`
+[tabs]
+======
+Java::
++
+[source, java, role="primary"]
+----
+class DocumentationTests {
+
+  ApplicationModules modules = ApplicationModules.of(Application.class);
+
+  @Test
+  void writeDocumentationSnippets() {
+
+    new Documenter(modules)
+      .writeAggregatingDocument();
+  }
+}
+----
+Kotlin::
++
+[source, kotlin, role="secondary"]
+----
+class DocumentationTests {
+
+  private val modules = ApplicationModules.of(Application::class)
+
+  @Test
+  fun writeDocumentationSnippets() {
+    Documenter(modules)
+        .writeAggregatingDocument()
+  }
+}
+----
+======
+
+The aggregating document will include any existing application module component diagrams and application module canvases. If there are none, then this method will not produce an output file.