reflect-metadata VS InversifyJS

We could use the reflect-metadata library to store the metadata and then scan it manually to replace the placeholders with actual values, but there is a better way.

Second, TypeScript 5.0 cannot emit decorator metadata. Subsequently, it doesn’t integrate with the Reflect API and won’t work with the reflect-metadata npm package.

Database columns will be mapped to domain object properties using decorators. This will include relationships and enum types. reflect-metadata stores metadata about the classes and properties. Most of the work is a simple map for each class, renaming db column properties to domain model properties and vice versa. Reflect.defineProperty holds a list of field metadata on the target class. This is where more database ORM logic could live in the future such as column type, length, etc. A base domain model entity will use this metadata to map the models appropriately.

One of the most popular libraries in JavaScript for implementing the Inversion of Control (IoC) pattern is InversifyJS. It provides a robust and flexible framework for managing dependencies in a clean, modular way. However, InversifyJS has some drawbacks. One major limitation is the amount of boilerplate code required to set up and manage dependencies. Additionally, it often requires structuring your application in a specific way, which may not suit every project.

Take a class for which we are tasked to write a unit test. This class may have a dozen methods and a dozen more attributes. In my environment we were already using inversify to dependency inject into this class, and using container snapshot and restore as setup and teardown operators, in our jest test file. But it began getting out of control even after refactoring into test cases and test runners.

Inversify (https://inversify.io/) for IoC.

Alguns frameworks trabalham desta forma por padrão, como é o caso do Angular, quando este não é o padrão do framework que utilizamos podemos usar alguma biblioteca, como a Inversify ou tsyringe da Microsoft.

Using decorators required setting an --experimentalDecorators experimental compiler flag. Several popular TypeScript libraries, such as type-graphql and inversify, rely on this implementation.

inversify

It blows 🤯 my mind to think that my #opensource project InversifyJS has reached over 100 MILLION DOWNLOADS on npm. InversifyJS is a lightweight (<50KB) but powerful Inversion Of Control (IoC) container for #JavaScript applications powered by #TypeScript. It is used to implement Dependency Injection (DI) in thousands of applications, including high-profile products like Microsoft Sway and over forty thousand open source repositories on #GitHub and over two thousand open source packages on #npm.

we use https://inversify.io/ in production, it works great.