Files
billit/internal/gst/calculator_test.go
Arkaprabha Chakraborty 28733e22d3 quite a lot of things
2025-12-06 03:05:44 +05:30

123 lines
3.7 KiB
Go

package gst
import (
"testing"
)
func TestCalculateLineItem(t *testing.T) {
c := NewCalculator()
product := Product{
SKU: "TEST01",
BasePrice: 100,
WholesalePrice: 90,
GSTRate: Rate18,
}
// Case 1: Retail, Intra-state
item := c.CalculateLineItem(product, 2, CustomerRetail, false)
if item.UnitPrice != 100 {
t.Errorf("Expected UnitPrice 100, got %f", item.UnitPrice)
}
if item.TaxableVal != 200 {
t.Errorf("Expected TaxableVal 200, got %f", item.TaxableVal)
}
if item.CGSTAmount != 18 { // 9% of 200
t.Errorf("Expected CGST 18, got %f", item.CGSTAmount)
}
if item.IGSTAmount != 0 {
t.Errorf("Expected IGST 0, got %f", item.IGSTAmount)
}
if item.TotalAmount != 236 { // 200 + 18 + 18
t.Errorf("Expected Total 236, got %f", item.TotalAmount)
}
// Case 2: Wholesale, Inter-state
item = c.CalculateLineItem(product, 10, CustomerWholesale, true)
if item.UnitPrice != 90 {
t.Errorf("Expected UnitPrice 90, got %f", item.UnitPrice)
}
if item.TaxableVal != 900 {
t.Errorf("Expected TaxableVal 900, got %f", item.TaxableVal)
}
if item.CGSTAmount != 0 {
t.Errorf("Expected CGST 0, got %f", item.CGSTAmount)
}
if item.IGSTAmount != 162 { // 18% of 900
t.Errorf("Expected IGST 162, got %f", item.IGSTAmount)
}
if item.TotalAmount != 1062 { // 900 + 162
t.Errorf("Expected Total 1062, got %f", item.TotalAmount)
}
}
func TestCalculateInvoice(t *testing.T) {
c := NewCalculator()
product := Product{SKU: "TEST01", BasePrice: 100, GSTRate: Rate18}
item1 := c.CalculateLineItem(product, 1, CustomerRetail, false)
item2 := c.CalculateLineItem(product, 1, CustomerRetail, false)
// Test with convenience fee (intra-state)
invoice := c.CalculateInvoice([]LineItem{item1, item2}, 50, false)
// Convenience fee is taxed at 18%
// SubTotal should include convenience fee: 100 + 100 + 50 = 250
expectedSubTotal := 250.0
if invoice.SubTotal != expectedSubTotal {
t.Errorf("Expected SubTotal %f, got %f", expectedSubTotal, invoice.SubTotal)
}
// Convenience fee tax: 50 * 0.18 = 9
expectedFeeTax := 9.0
if invoice.ConvenienceFeeTax != expectedFeeTax {
t.Errorf("Expected ConvenienceFeeTax %f, got %f", expectedFeeTax, invoice.ConvenienceFeeTax)
}
// Total CGST: 9 + 9 + 4.5 = 22.5 (from items + half of fee tax)
expectedCGST := 22.5
if invoice.TotalCGST != expectedCGST {
t.Errorf("Expected TotalCGST %f, got %f", expectedCGST, invoice.TotalCGST)
}
// GrandTotal: SubTotal + CGST + SGST = 250 + 22.5 + 22.5 = 295
expectedTotal := 295.0
if invoice.GrandTotal != expectedTotal {
t.Errorf("Expected GrandTotal %f, got %f", expectedTotal, invoice.GrandTotal)
}
}
func TestCalculateInvoiceInterState(t *testing.T) {
c := NewCalculator()
product := Product{SKU: "TEST01", BasePrice: 100, GSTRate: Rate18}
item := c.CalculateLineItem(product, 1, CustomerRetail, true)
// Test with convenience fee (inter-state)
invoice := c.CalculateInvoice([]LineItem{item}, 50, true)
// SubTotal: 100 + 50 = 150
expectedSubTotal := 150.0
if invoice.SubTotal != expectedSubTotal {
t.Errorf("Expected SubTotal %f, got %f", expectedSubTotal, invoice.SubTotal)
}
// Convenience fee tax: 50 * 0.18 = 9
expectedFeeTax := 9.0
if invoice.ConvenienceFeeTax != expectedFeeTax {
t.Errorf("Expected ConvenienceFeeTax %f, got %f", expectedFeeTax, invoice.ConvenienceFeeTax)
}
// Total IGST: 18 + 9 = 27 (from item + fee tax)
expectedIGST := 27.0
if invoice.TotalIGST != expectedIGST {
t.Errorf("Expected TotalIGST %f, got %f", expectedIGST, invoice.TotalIGST)
}
// GrandTotal: SubTotal + IGST = 150 + 27 = 177
expectedTotal := 177.0
if invoice.GrandTotal != expectedTotal {
t.Errorf("Expected GrandTotal %f, got %f", expectedTotal, invoice.GrandTotal)
}
}