feat: support plantUML classDiagram syntax (#13)

* feat: support plantUML syntax

* chore: update readme

* refactor: change if to switch statement

* docs: extend jsdoc with available options

* refactor: switch statement

* chore: extend jsodc

README.md

@@ -28,4 +28,9 @@ const defaultOutput = appRelationsDiscovery.getRelations(...docs);
 - For mermaid Flowchart 
 ```javascript
 const mermaidFlowchart = appRelationsDiscovery.getRelations(...docs,{syntax:'mermaid'});
+```
+
+- For plantUML classDiagram 
+```javascript
+const plantUMLClassDiagram = appRelationsDiscovery.getRelations(...docs,{syntax:'plantUML'});
 ```

lib/appRelationsDiscovery.js

@@ -1,7 +1,8 @@
 const getMermaidFlowchart = require('./getMermaidFlowchart');
+const getPlantUMLDiagram = require('./getPlantUMLDiagram');
 const {validate} = require('./utils');
 
-const supportedSyntax = ['default','mermaid'];
+const supportedSyntax = ['default','mermaid','plantUML'];
 
 const defaultOptions = {
   syntax: 'default',
@@ -11,7 +12,8 @@ const defaultOptions = {
  * Validates and analyzes a list of AsyncAPI documents and get applications described by those files
  * 
  * @param {Array} asyncApiDocs An array of asyncApiDocuments
- * @param {Object} options for getting a relations
+ * @param {Object} [options]
+ * @param {('default'|'mermaid'|'plantUML')} [options.syntax] syntax in which the relation will be generated.
  * @returns {Promise<DiscoveredRelations>} Relations between documents
  */
 // eslint-disable-next-line sonarjs/cognitive-complexity
@@ -74,10 +76,14 @@ async function getRelations(asyncApiDocs, { syntax } = defaultOptions) {
       };
     }
   });
-  if (syntax === 'default')
-    return metrics;
-  if (syntax === 'mermaid')
+  switch (syntax) {
+  case 'mermaid':
     return getMermaidFlowchart(metrics);
+  case 'plantUML':
+    return getPlantUMLDiagram(metrics);
+  default: 
+    return metrics;
+  }
 };
 
 module.exports = {getRelations};

lib/getPlantUMLDiagram.js

@@ -0,0 +1,30 @@
+/**
+ * Generates plantUML class diagram from default output syntax
+ * 
+ * @param {Object} metrics Relations between AsyncAPI docs in default output syntax
+ * @returns {String} class diagram following plantUML syntax
+ */
+function getPlantUMLDiagram(metrics) {
+  let i=1;
+  let plantUMLSyntax = '';
+  metrics.forEach((relations,server) => {
+    const [url, protocol] = server.split(',');
+    plantUMLSyntax+= `\nclass server${i} { \n url: ${url} \n protocol: ${protocol}\n}`;
+
+    relations.forEach((operations, channel) => {
+      operations.sub.forEach((metadata,subscriber) => {
+        const service = subscriber.replace(/\s/g,'');
+        plantUMLSyntax+=`\n${service} --|> server${i}:${channel}`;
+      });
+
+      operations.pub.forEach((metadata,publisher) => {
+        const service = publisher.replace(/\s/g,'');
+        plantUMLSyntax+=`\nserver${i} --|> ${service}:${channel}`;
+      });
+    });
+    i++;
+  });
+  return `@startuml\ntitle Classes - Class Diagram\n${plantUMLSyntax}\n@enduml`;
+}
+
+module.exports = getPlantUMLDiagram;