Can't save a ES6 Map or Set variable as a string or blob type in the …

…column

test/functional/columns/value-transformer/entity/PhoneBook.ts

@@ -0,0 +1,31 @@
+import {Entity} from "../../../../../src/decorator/entity/Entity";
+import {Column} from "../../../../../src/decorator/columns/Column";
+import {ValueTransformer} from "../../../../../src/decorator/options/ValueTransformer";
+import {PrimaryGeneratedColumn} from "../../../../../src/decorator/columns/PrimaryGeneratedColumn";
+
+
+class PhonesTransformer implements ValueTransformer {
+
+    to (value: Map<string, number>): string {
+        return JSON.stringify([...value]);
+    }
+
+    from (value: string): Map<string, number> {
+        return new Map(JSON.parse(value));
+    }
+
+}
+
+@Entity()
+export class PhoneBook {
+
+    @PrimaryGeneratedColumn()
+    id: number;
+
+    @Column()
+    name: string;
+
+    @Column({ type: String, transformer: new PhonesTransformer() })
+    phones: Map<string, number>;
+
+}

test/functional/columns/value-transformer/value-transformer.ts

@@ -3,17 +3,18 @@ import {expect} from "chai";
 import {closeTestingConnections, createTestingConnections, reloadTestingDatabases} from "../../../utils/test-utils";
 import {Connection} from "../../../../src/connection/Connection";
 import {Post} from "./entity/Post";
+import { PhoneBook } from "./entity/PhoneBook";
 
 describe("columns > value-transformer functionality", () => {
 
     let connections: Connection[];
     before(async () => connections = await createTestingConnections({
-        entities: [Post],
+        entities: [Post, PhoneBook],
     }));
     beforeEach(() => reloadTestingDatabases(connections));
     after(() => closeTestingConnections(connections));
 
-    it("should marshal data using the provided value-transformer", () => Promise.all(connections.map(async connection => {
+    it.only("should marshal data using the provided value-transformer", () => Promise.all(connections.map(async connection => {
 
         const postRepository = connection.getRepository(Post);
 
@@ -33,6 +34,22 @@ describe("columns > value-transformer functionality", () => {
         expect(loadedPost!.title).to.be.equal("About columns1");
         expect(loadedPost!.tags).to.deep.eq(["very", "simple"]);
 
+
+        const phoneBookRepository = connection.getRepository(PhoneBook);
+        const phoneBook = new PhoneBook();
+        phoneBook.name = "George";
+        phoneBook.phones = new Map();
+        phoneBook.phones.set("work", 123456);
+        phoneBook.phones.set("mobile", 1234567);
+        await phoneBookRepository.save(phoneBook);
+
+        const loadedPhoneBook = await phoneBookRepository.findOne(1);
+        expect(loadedPhoneBook!.name).to.be.equal("George");
+        expect(loadedPhoneBook!.phones).not.to.be.undefined;
+        expect(loadedPhoneBook!.phones.get("work")).to.equal(123456);
+        expect(loadedPhoneBook!.phones.get("mobile")).to.equal(1234567);
+
+
     })));
 
 

tsconfig.json

@@ -16,7 +16,8 @@
         "stripInternal": true,
         "pretty": true,
         "strictNullChecks": true,
-        "noUnusedLocals": true
+        "noUnusedLocals": true,
+        "downlevelIteration": true
     },
     "exclude": [
         "tmp",