hunk.code_window: You can run following command:
   ```
   typeorm migrations:generate -n PostRefactoring
   ```
   And it will generate a new migration called `{TIMESTAMP}-PostRefactoring.ts` with the following content:
  
hunk.labels: keep keep keep replace keep keep keep
hunk.after_edit: typeorm migration:generate -n PostRefactoring
  
hunk.file_path: docs/migrations.md
hunk.type: replace
file: import "reflect-metadata";
  import {closeTestingConnections, createTestingConnections, reloadTestingDatabases} from "../../utils/test-utils";
  import {Connection} from "../../../src/connection/Connection";
  import {Post} from "./entity/Post";
  
  describe("github issues > #1576 Entities with null as `id` are merged [@next]", () => {
  
      let connections: Connection[];
      before(async () => connections = await createTestingConnections({
          entities: [__dirname + "/entity/*{.js,.ts}"],
          enabledDrivers: ["postgres"]
      }));
      beforeEach(() => reloadTestingDatabases(connections));
      after(() => closeTestingConnections(connections));
  
      it("should successfully create object", () => Promise.all(connections.map(async connection => {
  
          const cats = [
              { id: null, name2: "1" },
              { id: null, name: "2", name2: null },
          ];
  
          const post = connection.manager.create(Post, {
              categories: cats
          });
  
          console.log(post);
      })));
  
  });
  