[BUG] Entity constructor overrides attributes on projection/selective Get

[iak4v]

Summary:

Love this library for managing my dynamoDB table!

However I came across a bug, when I try to get a item using .get({..}, {attributes: [..]}) method, constructor overrides other attribute values which do not match the true value from the DB.

Code sample:

await UserManager.create(new User({ email: "user1@example.com", name: "User 1" }));
await UserManager.update({ email: "user1@example.com" }, { set: { createdAt: new Date("2000-01-01T12:00:00Z"), isAdmin: true } });

const user1 = await UserManager.get({ email: "user1@example.com" }, { attributes: ["name"] });
console.log(user1.isAdmin) // ❌ returns false instead of true
console.log(user1.createdAt) // ❌ returns current date and not matches the updated date value from DB

On the other hand

await UserManager.create(new User({ email: "user2@example.com", name: "User 2" }));
await UserManager.update({ email: "user2@example.com" }, { set: { createdAt: new Date("2000-01-01T12:00:00Z"), isAdmin: true } });

const user2 = await UserManager.get({ email: "user2@example.com" });
console.log(user2.isAdmin) // ✅ returns true as expected
console.log(user2.createdAt) // ✅ returns updated date value from DB as expected

Model

import { attribute, Dynamode, Entity, TableManager } from "dynamode";

Dynamode.ddb.local();

export class User extends Entity {
    @attribute.partitionKey.string()
    email: string;

    @attribute.string()
    name: string;

    @attribute.boolean()
    isAdmin: boolean;

    @attribute.date.string()
    createdAt: Date;

    constructor(props: { email: string, name: string, isAdmin?: boolean, createdAt?: Date }) {
        super();
        this.email = props.email;
        this.name = props.name;
        this.isAdmin = props.isAdmin || false;
        this.createdAt = props.createdAt || new Date();
    }
}

const UserTableManager = new TableManager(User, {
    tableName: "Users",
    partitionKey: "email",
    createdAt: "createdAt"
})

export const UserManager = UserTableManager.entityManager();

try { await UserTableManager.createTable() } catch { } // created already

Action performed:

If I try to get an item from db, the values in it changes based on the attributes array

Expected result:

Retrieved item should be same and match the true value from DB irrespective of attributes array I provide

Actual result:

Retrieved item differs and do not match the true value from DB based on attributes array I provide

Environment:

Operating System & version: Windows 11 x64-based processor
Node.js version: v22.18.0
NPM version: 10.9.3
Dynamode version: ^1.5.0

Other:

• I have read through the Dynamode documentation before posting this issue
• I have searched through the GitHub issues (including closed issues) and pull requests to ensure this issue has not already been raised before
• I have searched the internet to ensure this issue hasn't been raised or answered before

[blazejkustra]

Hey @i-akv 👋 I fixed the issue in #45. Would you mind trying it out before I release it?

Try installing this release candidate and let me know!

npm i dynamode@1.6.0-rc.1

[iak4v]

Working as expected ✅

• No more overriding of values in the constructor
• Only required attributes are fetched with type safety

Ready for the release 🚀

[blazejkustra]

@i-akv Released in 1.6.0 🤝

[blazejkustra]

Consider starring the repo if you haven't already! ⭐ Also, do you have any other concerns/questions/suggestions? Maybe docs are confusing or something isn't working as you imagined? @i-akv