@nivinjoseph/n-domain/src/domain-helper.ts

Domain Driven Design and Event Sourcing based framework for business layer implementation

// import { Uuid } from "@nivinjoseph/n-util";
import { given } from "@nivinjoseph/n-defensive";
// import { ulid } from "ulid";
import { monotonicFactory } from "ulid";
const ulid = monotonicFactory();

// public
export class DomainHelper
{
    public static get now(): number { return Date.now(); }


    // public static generateId(prefix: string): string
    // {
    //     given(prefix, "prefix").ensureHasValue().ensureIsString()
    //         .ensure(t => t.trim().length === 3, "should be 3 chars long")
    //         .ensure((t) => t.matchesFormat("@@@"), "should contain only alphabet chars");
        
    //     // 4 + 32 = 36
    //     return `${prefix.trim().toLowerCase()}_${Uuid.create().replaceAll("-", "")}`;
    // }
    
    public static generateId(prefix: string): string
    {
        given(prefix, "prefix").ensureHasValue().ensureIsString()
            .ensure(t => t.trim().length === 3, "should be 3 chars long")
            .ensure((t) => t.matchesFormat("@@@"), "should contain only alphabet chars");
        
        const date = new Date();
        const year = date.getUTCFullYear().toString().substring(2);
        const month = ((date.getUTCMonth() + 1) / 100).toFixed(2).split(".").takeLast();
        const day = (date.getUTCDate() / 100).toFixed(2).split(".").takeLast();
        
        const dateValue = `${year}${month}${day}`;
        
        // 4 + 32 = 36
        return `${prefix.trim().toLowerCase()}_${dateValue}${ulid(date.valueOf())}`.toLowerCase();
    }
    
    public static aggregateTypeToSnakeCase(aggregateType: Function): string
    {
        let aggregateName = (<Object>aggregateType).getTypeName();
        const re = /[A-Z]/g;

        let index = aggregateName.search(re);
        while (index !== -1)
        {
            const char = aggregateName[index];
            const replacement = "_" + char.toLowerCase();
            aggregateName = aggregateName.replace(char, replacement);

            index = aggregateName.search(re);
        }

        if (aggregateName.startsWith("_"))
            aggregateName = aggregateName.substring(1);

        return aggregateName;
    }
}