Emit decorator metadata

[tada5hi]

Describe the bug

When switching from tsc to swc to transpile TypeScript to JavaScript code, the swc transpiler sets for union types with null the metadata to: Object

ts

import {
    Column,
    CreateDateColumn,
    Entity,
    JoinColumn,
    ManyToOne,
    PrimaryGeneratedColumn,
    Unique,
    UpdateDateColumn,
} from 'typeorm';
import { Client, Realm, User } from '@authup/common';
import { UserEntity } from '../user';
import { RealmEntity } from '../realm';

@Entity({ name: 'auth_clients' })
@Unique(['name', 'realm_id'])
export class ClientEntity implements Client {
    @PrimaryGeneratedColumn('uuid')
        id: string;

    @Column({
        type: 'varchar',
        length: 256,
    })
        name: string;

    @Column({
        type: 'text',
        nullable: true,
    })
        description: string | null;

    @Column({
        type: 'varchar',
        length: 256,
        select: false,
        nullable: true,
    })
        secret: string | null;

    @Column({
        type: 'text',
        nullable: true,
    })
        redirect_uri: string | null;

    @Column({
        type: 'varchar',
        length: 512,
        nullable: true,
    })
        grant_types: string | null;

    @Column({
        type: 'varchar',
        length: 512,
        nullable: true,
        default: null,
    })
        scope: string | null;

    @Column({
        type: 'varchar',
        length: 2000,
        nullable: true,
    })
        base_url: string | null;

    @Column({
        type: 'varchar',
        length: 2000,
        nullable: true,
    })
        root_url: string | null;

    @Column({
        type: 'boolean',
        default: false,
    })
        is_confidential: boolean;

    // ------------------------------------------------------------------

    @CreateDateColumn()
        created_at: Date;

    @UpdateDateColumn()
        updated_at: Date;

    // ------------------------------------------------------------------

    @Column({ default: null })
        realm_id: Realm['id'] | null;

    @ManyToOne(() => RealmEntity, { onDelete: 'CASCADE', nullable: true })
    @JoinColumn({ name: 'realm_id' })
        realm: RealmEntity | null;

    @Column({ nullable: true })
        user_id: User['id'] | null;

    @ManyToOne(() => UserEntity, { onDelete: 'CASCADE', nullable: true })
    @JoinColumn({ name: 'user_id' })
        user: UserEntity | null;
}

tsc compilation

"use strict";
var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
    return c > 3 && r && Object.defineProperty(target, key, r), r;
};
var __metadata = (this && this.__metadata) || function (k, v) {
    if (typeof Reflect === "object" && typeof Reflect.metadata === "function") return Reflect.metadata(k, v);
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.ClientEntity = void 0;
const typeorm_1 = require("typeorm");
const user_1 = require("../user");
const realm_1 = require("../realm");
let ClientEntity = class ClientEntity {
};
__decorate([
    (0, typeorm_1.PrimaryGeneratedColumn)('uuid'),
    __metadata("design:type", String)
], ClientEntity.prototype, "id", void 0);
__decorate([
    (0, typeorm_1.Column)({
        type: 'varchar',
        length: 256,
    }),
    __metadata("design:type", String)
], ClientEntity.prototype, "name", void 0);
__decorate([
    (0, typeorm_1.Column)({
        type: 'text',
        nullable: true,
    }),
    __metadata("design:type", String)
], ClientEntity.prototype, "description", void 0);
__decorate([
    (0, typeorm_1.Column)({
        type: 'varchar',
        length: 256,
        select: false,
        nullable: true,
    }),
    __metadata("design:type", String)
], ClientEntity.prototype, "secret", void 0);
__decorate([
    (0, typeorm_1.Column)({
        type: 'text',
        nullable: true,
    }),
    __metadata("design:type", String)
], ClientEntity.prototype, "redirect_uri", void 0);
__decorate([
    (0, typeorm_1.Column)({
        type: 'varchar',
        length: 512,
        nullable: true,
    }),
    __metadata("design:type", String)
], ClientEntity.prototype, "grant_types", void 0);
__decorate([
    (0, typeorm_1.Column)({
        type: 'varchar',
        length: 512,
        nullable: true,
        default: null,
    }),
    __metadata("design:type", String)
], ClientEntity.prototype, "scope", void 0);
__decorate([
    (0, typeorm_1.Column)({
        type: 'varchar',
        length: 2000,
        nullable: true,
    }),
    __metadata("design:type", String)
], ClientEntity.prototype, "base_url", void 0);
__decorate([
    (0, typeorm_1.Column)({
        type: 'varchar',
        length: 2000,
        nullable: true,
    }),
    __metadata("design:type", String)
], ClientEntity.prototype, "root_url", void 0);
__decorate([
    (0, typeorm_1.Column)({
        type: 'boolean',
        default: false,
    }),
    __metadata("design:type", Boolean)
], ClientEntity.prototype, "is_confidential", void 0);
__decorate([
    (0, typeorm_1.CreateDateColumn)(),
    __metadata("design:type", Date)
], ClientEntity.prototype, "created_at", void 0);
__decorate([
    (0, typeorm_1.UpdateDateColumn)(),
    __metadata("design:type", Date)
], ClientEntity.prototype, "updated_at", void 0);
__decorate([
    (0, typeorm_1.Column)({ default: null }),
    __metadata("design:type", Object)
], ClientEntity.prototype, "realm_id", void 0);
__decorate([
    (0, typeorm_1.ManyToOne)(() => realm_1.RealmEntity, { onDelete: 'CASCADE', nullable: true }),
    (0, typeorm_1.JoinColumn)({ name: 'realm_id' }),
    __metadata("design:type", realm_1.RealmEntity)
], ClientEntity.prototype, "realm", void 0);
__decorate([
    (0, typeorm_1.Column)({ nullable: true }),
    __metadata("design:type", Object)
], ClientEntity.prototype, "user_id", void 0);
__decorate([
    (0, typeorm_1.ManyToOne)(() => user_1.UserEntity, { onDelete: 'CASCADE', nullable: true }),
    (0, typeorm_1.JoinColumn)({ name: 'user_id' }),
    __metadata("design:type", user_1.UserEntity)
], ClientEntity.prototype, "user", void 0);
ClientEntity = __decorate([
    (0, typeorm_1.Entity)({ name: 'auth_clients' }),
    (0, typeorm_1.Unique)(['name', 'realm_id'])
], ClientEntity);
exports.ClientEntity = ClientEntity;
//# sourceMappingURL=entity.js.map

swc compilation

"use strict";
Object.defineProperty(exports, "__esModule", {
    value: true
});
Object.defineProperty(exports, "ClientEntity", {
    enumerable: true,
    get: ()=>ClientEntity
});
const _typeorm = require("typeorm");
const _user = require("../user");
const _realm = require("../realm");
var __decorate = (void 0) && (void 0).__decorate || function(decorators, target, key, desc) {
    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
    else for(var i = decorators.length - 1; i >= 0; i--)if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
    return c > 3 && r && Object.defineProperty(target, key, r), r;
};
var __metadata = (void 0) && (void 0).__metadata || function(k, v) {
    if (typeof Reflect === "object" && typeof Reflect.metadata === "function") return Reflect.metadata(k, v);
};
let ClientEntity = class ClientEntity {
};
__decorate([
    (0, _typeorm.PrimaryGeneratedColumn)('uuid'),
    __metadata("design:type", String)
], ClientEntity.prototype, "id", void 0);
__decorate([
    (0, _typeorm.Column)({
        type: 'varchar',
        length: 256
    }),
    __metadata("design:type", String)
], ClientEntity.prototype, "name", void 0);
__decorate([
    (0, _typeorm.Column)({
        type: 'text',
        nullable: true
    }),
    __metadata("design:type", Object)
], ClientEntity.prototype, "description", void 0);
__decorate([
    (0, _typeorm.Column)({
        type: 'varchar',
        length: 256,
        select: false,
        nullable: true
    }),
    __metadata("design:type", Object)
], ClientEntity.prototype, "secret", void 0);
__decorate([
    (0, _typeorm.Column)({
        type: 'text',
        nullable: true
    }),
    __metadata("design:type", Object)
], ClientEntity.prototype, "redirect_uri", void 0);
__decorate([
    (0, _typeorm.Column)({
        type: 'varchar',
        length: 512,
        nullable: true
    }),
    __metadata("design:type", Object)
], ClientEntity.prototype, "grant_types", void 0);
__decorate([
    (0, _typeorm.Column)({
        type: 'varchar',
        length: 512,
        nullable: true,
        default: null
    }),
    __metadata("design:type", Object)
], ClientEntity.prototype, "scope", void 0);
__decorate([
    (0, _typeorm.Column)({
        type: 'varchar',
        length: 2000,
        nullable: true
    }),
    __metadata("design:type", Object)
], ClientEntity.prototype, "base_url", void 0);
__decorate([
    (0, _typeorm.Column)({
        type: 'varchar',
        length: 2000,
        nullable: true
    }),
    __metadata("design:type", Object)
], ClientEntity.prototype, "root_url", void 0);
__decorate([
    (0, _typeorm.Column)({
        type: 'boolean',
        default: false
    }),
    __metadata("design:type", Boolean)
], ClientEntity.prototype, "is_confidential", void 0);
__decorate([
    (0, _typeorm.CreateDateColumn)(),
    __metadata("design:type", typeof Date === "undefined" ? Object : Date)
], ClientEntity.prototype, "created_at", void 0);
__decorate([
    (0, _typeorm.UpdateDateColumn)(),
    __metadata("design:type", typeof Date === "undefined" ? Object : Date)
], ClientEntity.prototype, "updated_at", void 0);
__decorate([
    (0, _typeorm.Column)({
        default: null
    }),
    __metadata("design:type", Object)
], ClientEntity.prototype, "realm_id", void 0);
__decorate([
    (0, _typeorm.ManyToOne)(()=>_realm.RealmEntity, {
        onDelete: 'CASCADE',
        nullable: true
    }),
    (0, _typeorm.JoinColumn)({
        name: 'realm_id'
    }),
    __metadata("design:type", Object)
], ClientEntity.prototype, "realm", void 0);
__decorate([
    (0, _typeorm.Column)({
        nullable: true
    }),
    __metadata("design:type", Object)
], ClientEntity.prototype, "user_id", void 0);
__decorate([
    (0, _typeorm.ManyToOne)(()=>_user.UserEntity, {
        onDelete: 'CASCADE',
        nullable: true
    }),
    (0, _typeorm.JoinColumn)({
        name: 'user_id'
    }),
    __metadata("design:type", Object)
], ClientEntity.prototype, "user", void 0);
ClientEntity = __decorate([
    (0, _typeorm.Entity)({
        name: 'auth_clients'
    }),
    (0, _typeorm.Unique)([
        'name',
        'realm_id'
    ])
], ClientEntity);

Input code

No response

Config

{
    "$schema": "https://json.schemastore.org/swcrc",
    "module": {
        "type": "commonjs"
    },
    "jsc": {
        "target": "es2016",
        "parser": {
            "syntax": "typescript",
            "decorators": true
        },
        "transform": {
            "decoratorMetadata": true,
            "legacyDecorator": true
        },
        "loose": true
    }
}

Playground link

No response

Expected behavior

It should choose the non null type in preference like the tsc compiler does. But I'm also not sure if the behavior differs in several aspects. I only noticed it for the union type.

Actual behavior

No response

Version

1.3.26

Additional context

No response

[tada5hi]

@kdy1 this would be really great if this works in the future :blush:, than it would also possible to transpile codebases which are based on decorators, like typeorm for example.

[kdy1]

It's definitely not a priority and I'm very busy. Also, please don't write comments like +1

[tada5hi]

6809

[tada5hi]

It's definitely not a priority and I'm very busy. Also, please don't write comments like +1

No problem ✌️. Nevertheless, thank you very much. Swc is a really nice transpiler and besides the decorator problem, which makes it unusable for some libraries/application, i hadn't any real problems with it yet.

[joshghent]

I would really love this feature if it can be supported! Our particular use case is that we are using the Routing-controllers. Thanks for SWC 🎉