added test for typeorm#3997

Author: AlexMesser

test/github-issues/3997/entity/Photo.ts

@@ -0,0 +1,19 @@
+import {Column, Entity, JoinColumn, ManyToOne, PrimaryGeneratedColumn} from "../../../../src";
+import {User} from "./User";
+
+@Entity()
+export class Photo {
+
+    @PrimaryGeneratedColumn()
+    id: number;
+
+    @Column()
+    name: string;
+
+    @Column()
+    userId: string;
+
+    @ManyToOne(_type => User, type => type.photos)
+    @JoinColumn({ name: 'userId' })
+    user: User;
+}

test/github-issues/3997/entity/User.ts

@@ -0,0 +1,17 @@
+import {Column, Entity, OneToMany, PrimaryGeneratedColumn} from "../../../../src";
+import {Photo} from "./Photo";
+
+@Entity()
+export class User {
+    @PrimaryGeneratedColumn()
+    id: number;
+
+    @Column()
+    name: string;
+
+    @Column("decimal", { precision: 9, scale: 6 })
+    height: number;
+
+    @OneToMany(_type => Photo, type => type.user, { cascade: true })
+    photos: Photo[];
+}

test/github-issues/3997/issue-3997.ts

@@ -0,0 +1,28 @@
+import "reflect-metadata";
+import {Connection} from "../../../src";
+import {closeTestingConnections, createTestingConnections} from "../../utils/test-utils";
+import {Photo} from "./entity/Photo";
+import {User} from "./entity/User";
+
+describe("github issues > #3997 synchronize=true always failing when using decimal column type with a foreign key constraint", () => {
+    let connections: Connection[];
+    before(async () => connections = await createTestingConnections({
+        schemaCreate: false,
+        dropSchema: true,
+        entities: [User, Photo],
+    }));
+    after(() => closeTestingConnections(connections));
+
+    it("should recognize model changes", () => Promise.all(connections.map(async connection => {
+        const sqlInMemory = await connection.driver.createSchemaBuilder().log();
+        sqlInMemory.upQueries.length.should.be.greaterThan(0);
+        sqlInMemory.downQueries.length.should.be.greaterThan(0);
+    })));
+
+    it("should not generate queries when no model changes", () => Promise.all(connections.map(async connection => {
+        await connection.driver.createSchemaBuilder().build();
+        const sqlInMemory = await connection.driver.createSchemaBuilder().log();
+        sqlInMemory.upQueries.length.should.be.equal(0);
+        sqlInMemory.downQueries.length.should.be.equal(0);
+    })));
+});