Implement HTML writer (#33)

Reviewed-on: #33
Co-authored-by: Natercio Moniz <[email protected]>

internal/writing/csv/writer_test.go

@@ -0,0 +1,78 @@
+package csv_test
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/nmoniz/any2anexoj/internal"
+	"github.com/nmoniz/any2anexoj/internal/writing/csv"
+	"github.com/shopspring/decimal"
+)
+
+func TestWriter_Render(t *testing.T) {
+	aw := internal.NewAggregatorWriter()
+	ctx := t.Context()
+
+	items := []internal.ReportItem{
+		{
+			Symbol:        "AAPL",
+			Nature:        internal.NatureG01,
+			BrokerCountry: 826, // United Kingdom
+			AssetCountry:  840, // United States
+			BuyValue:      decimal.NewFromFloat(100.50),
+			BuyTimestamp:  time.Date(2023, 1, 15, 0, 0, 0, 0, time.UTC),
+			SellValue:     decimal.NewFromFloat(150.75),
+			SellTimestamp: time.Date(2023, 6, 20, 0, 0, 0, 0, time.UTC),
+			Fees:          decimal.NewFromFloat(2.50),
+			Taxes:         decimal.NewFromFloat(5.00),
+		},
+		{
+			Symbol:        "VWRL",
+			Nature:        internal.NatureG20,
+			BrokerCountry: 196, // Portugal equivalent demo
+			AssetCountry:  372, // Ireland
+			BuyValue:      decimal.NewFromFloat(200.00),
+			BuyTimestamp:  time.Date(2024, 2, 1, 0, 0, 0, 0, time.UTC),
+			SellValue:     decimal.NewFromFloat(250.25),
+			SellTimestamp: time.Date(2024, 7, 10, 0, 0, 0, 0, time.UTC),
+			Fees:          decimal.NewFromFloat(1.00),
+			Taxes:         decimal.NewFromFloat(0.00),
+		},
+	}
+
+	for _, ri := range items {
+		if err := aw.Write(ctx, ri); err != nil {
+			t.Fatalf("write report item: %v", err)
+		}
+	}
+
+	var buf bytes.Buffer
+	if err := csv.NewWriter(&buf).Render(aw); err != nil {
+		t.Fatalf("render: %v", err)
+	}
+
+	out := buf.String()
+
+	wantHeader := "source_country,code,realization_year,realization_month,realization_day,realization_value,acquisition_year,acquisition_month,acquisition_day,acquisition_value,expenses,foreign_tax_paid,counter_country"
+	if !strings.HasPrefix(out, wantHeader+"\n") {
+		t.Errorf("expected header row %q, got output:\n%s", wantHeader, out)
+	}
+
+	wantRow1 := "840,G01,2023,6,20,150.75,2023,1,15,100.50,2.50,5.00,826"
+	if !strings.Contains(out, wantRow1+"\n") {
+		t.Errorf("expected row 1 %q in output:\n%s", wantRow1, out)
+	}
+
+	wantRow2 := "372,G20,2024,7,10,250.25,2024,2,1,200.00,1.00,0.00,196"
+	if !strings.Contains(out, wantRow2+"\n") {
+		t.Errorf("expected row 2 %q in output:\n%s", wantRow2, out)
+	}
+
+	// Make sure the header only appears once and we have exactly 1 header + 2 data rows.
+	lines := strings.Split(strings.TrimRight(out, "\n"), "\n")
+	if got, want := len(lines), 3; got != want {
+		t.Errorf("expected %d lines (1 header + 2 rows), got %d:\n%s", want, got, out)
+	}
+}