books/accounting/ledgerPosting.js

const frappe = require('frappejs');

module.exports = class LedgerPosting {
  constructor({ reference, party, date, description }) {
    Object.assign(this, arguments[0]);
    this.entries = [];
    this.entryMap = {};
  }

  debit(account, amount, referenceType, referenceName) {
    const entry = this.getEntry(account, referenceType, referenceName);
    entry.debit += amount;
  }

  credit(account, amount, referenceType, referenceName) {
    const entry = this.getEntry(account, referenceType, referenceName);
    entry.credit += amount;
  }

  getEntry(account, referenceType, referenceName) {
    if (!this.entryMap[account]) {
      const entry = {
        account: account,
        party: this.party || '',
        date: this.date || this.reference.date,
        referenceType: referenceType || this.reference.doctype,
        referenceName: referenceName || this.reference.name,
        description: this.description,
        debit: 0,
        credit: 0
      };

      this.entries.push(entry);
      this.entryMap[account] = entry;
    }

    return this.entryMap[account];
  }

  async post() {
    this.validateEntries();
    await this.insertEntries();
  }

  async postReverse() {
    this.validateEntries();
    let temp;
    for (let entry of this.entries) {
      temp = entry.debit;
      entry.debit = entry.credit;
      entry.credit = temp;
    }
    await this.insertEntries();
  }

  validateEntries() {
    let debit = 0;
    let credit = 0;
    let debitAccounts = [];
    let creditAccounts = [];

    for (let entry of this.entries) {
      debit += entry.debit;
      credit += entry.credit;
      if (debit) {
        debitAccounts.push(entry.account);
      } else {
        creditAccounts.push(entry.account);
      }
    }

    if (debit !== credit) {
      throw new frappe.errors.ValidationError(frappe._('Debit {0} must be equal to Credit {1}', [debit, credit]));
    }
  }

  async insertEntries() {
    for (let entry of this.entries) {
      let entryDoc = frappe.newDoc({
        doctype: 'AccountingLedgerEntry'
      });
      Object.assign(entryDoc, entry);
      await entryDoc.insert();
    }
  }
};