dependencyInjection.md

https://www.youtube.com/watch?v=J1f5b4vcxCQ

A piece of code using another piece of code that is passed in, instead of used directly.

The act of passing things to be used is called injection i.e. We inject the dependent code into the code that uses it.

Before

export class Storage(){
    private database: Database

    constructor(){
        this.database = New Database("db.sqlite");

        this.database.run(`
            CREATE TABLE IF NOT EXISTS user (
                id INTEGER PRIMARY KEY,
                username TEXT,
                group_id INTEGER,
                creation_time TIMESTAMP
            )
        `);
    }
}

After

export class Storage(){
    private database: Database

    constructor(database: Database){
        this.database = database;

        this.database.run(`
            CREATE TABLE IF NOT EXISTS user (
                id INTEGER PRIMARY KEY,
                username TEXT,
                group_id INTEGER,
                creation_time TIMESTAMP
            )
        `);
    }
}