merge of PR-2465: setup unit tests for federation

backend/src/config/index.ts

@@ -10,7 +10,7 @@ Decimal.set({
 })
 
 const constants = {
-  DB_VERSION: '0055-consistent_deleted_users',
+  DB_VERSION: '0056-add_communities_table',
   DECAY_START_TIME: new Date('2021-05-13 17:46:31-0000'), // GMT+0
   LOG4JS_CONFIG: 'log4js-config.json',
   // default log level on production should be info

backend/src/federation/index.test.ts

@@ -155,6 +155,25 @@ describe('federation', () => {
               expect(true).toBe(true)
             })
           })
+          describe('on data with receiving simply a string', () => {
+            beforeEach(() => {
+              socketEventMocks.data(
+                Buffer.from(
+                  `hello here is a new community and i don't know how to communicate with you`,
+                ),
+              )
+            })
+            it('logged the received data', () => {
+              expect(logger.info).toBeCalledWith(
+                `data: hello here is a new community and i don't know how to communicate with you`,
+              )
+            })
+            it('logged a warning of unexpected data format and structure', () => {
+              expect(logger.warn).toBeCalledWith(
+                `received totaly wrong or too much apiVersions-Definition JSON-String:hello here is a new community and i don't know how to communicate with you`,
+              )
+            })
+          })
         })
       })
     })

database/entity/Community.ts

@@ -1 +1 @@
-export { Community } from './0055-add_communities_table/Community'
+export { Community } from './0056-add_communities_table/Community'