feat(map): Codegen for JsonSchema Target

lib/codegen/fromcto/jsonschema/jsonschemavisitor.js

@@ -381,11 +381,6 @@ class JSONSchemaVisitor {
     visitField(field, parameters, isScalarUUID = false) {
         debug('entering visitField', field.getName());
 
-
-        if (ModelUtil.isMap?.(field)) {
-            return;
-        }
-
         // Is this a primitive typed property?
         let jsonSchema;
         if (field.isPrimitive()) {
@@ -411,6 +406,34 @@ class JSONSchemaVisitor {
                 jsonSchema.description = 'The instance identifier for this type';
             }
 
+        } else if (ModelUtil.isMap?.(field)) {
+            const mapDeclaration = field.getParent().getModelFile().getModelManager().getType(field.getFullyQualifiedTypeName());
+
+            let valueDeclaration = mapDeclaration.getModelFile()
+                .getAllDeclarations()
+                .find(decl => decl.name === mapDeclaration.getValue().getType());
+
+            const jsonSchema = {
+                $id: field.getFullyQualifiedName(),
+                schema: {
+                    title: mapDeclaration.getName(),
+                    description : `An instance of ${field.getFullyQualifiedTypeName()}`,
+                    type: 'object',
+                    propertyNames: {
+                        type: 'string'
+                    },
+                    additionalProperties: {
+                        type: this.toJsonType(mapDeclaration.getValue().getType())
+                    }
+                }
+            };
+
+            // if its a ClassDeclaration, add reference to its schema.
+            if (valueDeclaration?.isClassDeclaration()) {
+                jsonSchema.schema.additionalProperties.$ref = `#/definitions/${field.getParent().getModelFile().getNamespace().concat(`.${mapDeclaration.getValue().getType()}`)}`;
+            }
+
+            return jsonSchema;
         // Not primitive, so must be a class or enumeration!
         } else {
             // Look up the type of the property.
@@ -546,6 +569,29 @@ class JSONSchemaVisitor {
         // Return the schema.
         return jsonSchema;
     }
+
+    /**
+     * Converts a Concerto type to a JSON type. Primitive types are converted
+     * everything else is passed through unchanged.
+     * @param {string} type  - the concerto type
+     * @return {string} the corresponding type in Json
+     * @private
+     */
+    toJsonType(type) {
+        switch (type) {
+        case 'Boolean':
+            return 'boolean';
+        case 'String':
+        case 'DateTime':
+            return 'string';
+        case 'Double':
+        case 'Long':
+        case 'Integer':
+            return 'number';
+        default:
+            return type;
+        }
+    }
 }
 
 module.exports = JSONSchemaVisitor;