feat: validate generated schemas

Fixes #1

src/schema.ts

@@ -12,6 +12,7 @@
  * You should have received a copy of the GNU General Public License along with
  * this program. If not, see <https://www.gnu.org/licenses/>.
  */
+import * as ajv from 'ajv';
 import {Schema as JSONSchema} from 'jsonschema';
 import {join} from 'path';
 import {DEFAULT_CONFIG, SchemaGenerator} from 'ts-json-schema-generator';
@@ -29,6 +30,7 @@ import {isSchemaWithDefinitions} from './common';
  */
 export class Converter {
   private generator: SchemaGenerator;
+  private schemaValidator: ajv.Ajv;
 
   /**
    * Create a new converter
@@ -56,6 +58,10 @@ export class Converter {
       createParser(program, config),
       createFormatter(config),
     );
+
+    // create ajv instance
+    this.schemaValidator = new ajv();
+    this.schemaValidator.addMetaSchema(require('ajv/lib/refs/json-schema-draft-06.json'));
   }
 
   /**
@@ -73,8 +79,21 @@ export class Converter {
     schema.id = 'https://core.stapps.tu-berlin.de/v' + version + '/lib/schema/' + type + '.json';
 
     if (isSchemaWithDefinitions(schema)) {
+      const selfReference = {
+        ...{},
+        ...schema,
+      };
+
+      delete selfReference.$schema;
+      delete selfReference.definitions;
+      delete selfReference.id;
+
       // add self reference to definitions
-      schema.definitions['SC' + type] = Object.assign({}, schema.properties);
+      schema.definitions['SC' + type] = Object.assign({}, selfReference as any);
+    }
+
+    if (!this.schemaValidator.validateSchema(schema)) {
+      throw new Error(`Generated schema for ${type} is invalid!`);
     }
 
     return schema;