feat: add method to remove references from a thing

Fixes #6

test/connectorClient.spec.ts

@@ -12,7 +12,9 @@
  * 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 {asyncPool} from '@krlwlfrt/async-pool';
 import {
+  isThing,
   SCBulkAddResponse,
   SCBulkAddRoute,
   SCBulkDoneResponse,
@@ -20,17 +22,22 @@ import {
   SCBulkResponse,
   SCBulkRoute,
   SCMessage,
+  SCThing,
+  SCThingOriginType,
+  SCThingType,
   SCThingUpdateResponse,
   SCThingUpdateRoute,
-  SCThingType,
-  SCThingOriginType,
 } from '@openstapps/core';
 import * as chai from 'chai';
 import {expect} from 'chai';
 import * as chaiAsPromised from 'chai-as-promised';
 import * as chaiSpies from 'chai-spies';
+import {readdir, readFile} from 'fs';
 import {suite, test} from 'mocha-typescript';
 import * as moment from 'moment';
+import {join, resolve} from 'path';
+import * as traverse from 'traverse';
+import {promisify} from 'util';
 import {ConnectorClient} from '../src/connectorClient';
 import {EmptyBulkError, NamespaceNotDefinedError} from '../src/errors';
 import {HttpClient} from '../src/httpClient';
@@ -47,8 +54,27 @@ const bulkDoneRoute = new SCBulkDoneRoute();
 const bulkRoute = new SCBulkRoute();
 const thingUpdateRoute = new SCThingUpdateRoute();
 
+const readdirPromisified = promisify(readdir);
+const readFilePromisified = promisify(readFile);
+
 const httpClient = new HttpClient();
 
+/**
+ * Check if something contains things
+ *
+ * @param thing Thing to check
+ */
+function doesContainThings<T extends SCThing>(thing: T): boolean {
+  /* tslint:disable-next-line:only-arrow-functions */
+  return traverse(thing).reduce(function(sum, item) {
+    if (this.isRoot) {
+      return false;
+    }
+
+    return sum || (item === null) ? false : isThing(item);
+  }, false);
+}
+
 @suite()
 export class ConnectorClientSpec {
   async after() {
@@ -305,6 +331,36 @@ export class ConnectorClientSpec {
     }).to.throw(NamespaceNotDefinedError);
   }
 
+  @test
+  async removeReferences() {
+    const pathToTestFiles = resolve(
+      __dirname,
+      '..',
+      'node_modules',
+      '@openstapps',
+      'core',
+      'test',
+      'resources',
+    );
+
+    const testFiles = await readdirPromisified(pathToTestFiles);
+
+    const testInstances = await asyncPool(5, testFiles, async (testFile) => {
+      const buffer = await readFilePromisified(join(pathToTestFiles, testFile));
+      const content = JSON.parse(buffer.toString());
+      return content.instance;
+    });
+
+    for (const testInstance of testInstances) {
+      const testInstanceWithoutReferences = ConnectorClient.removeReferences(testInstance);
+      expect(doesContainThings(testInstanceWithoutReferences)).to.be.equal(false, JSON.stringify(
+        [testInstance, testInstanceWithoutReferences],
+        null,
+        2,
+      ));
+    }
+  }
+
   @test
   async update() {
     const message: SCMessage = {