feat: add help message about AnonymousSchema generated classes (#211)

hooks/98_userHelp.js

@@ -0,0 +1,57 @@
+const fs = require('fs');
+
+function checkForAnonymousSchemaObjects(generator) {
+    const modelPath = generator.targetDir + '/src/main/java/com/asyncapi/model';
+    var anonymousPresent = false;
+    var anonymousFileNames = [];
+    fs.readdirSync(modelPath).forEach(file => {
+        if (file.startsWith('AnonymousSchema')) {
+            anonymousPresent = true;
+            anonymousFileNames.push(generator.templateParams['userJavaPackage'].replace(/\./g, '/') + '/model/' + file);
+        }
+    });
+    if (anonymousPresent) {
+  console.log(`Following AnonymousSchema classes were generated in DTO classes:
+${anonymousFileNames.toString()}\n
+This may be a result of explicit (composition, inheritance, array items) Schema Object definition e.g.\n
+    schemas:
+      NamedObject:
+      type: object
+        properties:
+          field:
+            type: array
+            items:
+              type: object #Anonymous object
+              properties:
+                field:
+                  type: string
+\nOR\n
+    messages:
+      Message:
+        payload:
+          type: object #Anonymous object
+          properties:\n
+Please move such elements to child of "schemas:" to define proper names.
+If changing of data model is not possible, you may use "$id" to set name e.g.\n
+    properties:
+      field:
+        type: array
+        items:
+          $id: ArrayElement #Name of object
+          type: object
+          properties:
+            field:
+              type: string`);
+    }
+}
+
+module.exports = {
+    /**
+     * Print help information for user if problems encountered during generation.
+     *
+     * @param generator
+     */
+    'generate:after': generator => {
+        checkForAnonymousSchemaObjects(generator);
+    }
+};