1 files changed, 118 insertions, 0 deletions
diff --git a/internal/mapping/mapping_test.go b/internal/mapping/mapping_test.go
new file mode 100644
index 0000000..d9190cd
--- /dev/null
+++ b/internal/mapping/mapping_test.go
@@ -0,0 +1,118 @@
+package mapping
+
+import (
+	"errors"
+	"testing"
+	"time"
+
+	"simenandre.no/accounted-multicase-intgr/internal/accounted"
+	"simenandre.no/accounted-multicase-intgr/internal/multicase"
+)
+
+func config() *Config {
+	return &Config{
+		Accounts:              map[string]string{"3000": "3001", "1460": "1460", "4301": "4000"},
+		CustomerLedgerAccount: "1510",
+		VATCodes: map[string]VATCode{
+			"3": {Rate: 25, Account: "2611"},
+			"6": {Rate: 0},
+		},
+		RoundingAccount: "3740",
+		MaxRoundingOre:  100,
+		SourceType:      "manual",
+	}
+}
+
+func voucher(lines ...multicase.Line) multicase.Voucher {
+	return multicase.Voucher{
+		Type: "11", TypeText: "Faktura", Number: "100", Text: "Demo kunde",
+		Date: time.Date(2026, 10, 1, 0, 0, 0, 0, time.UTC), Lines: lines,
+	}
+}
+
+func TestSplitNet(t *testing.T) {
+	tests := []struct {
+		gross, want int64
+		rate        float64
+	}{
+		{270019, 216015, 25},
+		{-270019, -216015, 25},
+		{12500, 10000, 25},
+		{1, 1, 25},
+		{11200, 10000, 12},
+		{5000, 5000, 0},
+	}
+	for _, tt := range tests {
+		if got := SplitNet(tt.gross, tt.rate); got != tt.want {
+			t.Errorf("SplitNet(%d, %v) = %d, want %d", tt.gross, tt.rate, got, tt.want)
+		}
+	}
+}
+
+func TestBuildSplitsVATAndMapsCustomerLedger(t *testing.T) {
+	e, err := config().Build(voucher(
+		multicase.Line{Account: "3000", Amount: -270019, VATCode: "3", CustomerNo: "20001"},
+		multicase.Line{Account: "20001", Amount: 270019, CustomerNo: "20001"},
+	))
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := []accounted.Line{
+		{Account: "3001", Credit: 216015},
+		{Account: "2611", Credit: 54004},
+		{Account: "1510", Debit: 270019},
+	}
+	if len(e.Lines) != len(want) {
+		t.Fatalf("lines = %+v", e.Lines)
+	}
+	for i, w := range want {
+		g := e.Lines[i]
+		if g.Account != w.Account || g.Debit != w.Debit || g.Credit != w.Credit {
+			t.Errorf("line %d = %+v, want %+v", i, g, w)
+		}
+	}
+	if e.SourceID != "multicase:11:100" || e.EntryDate != "2026-10-01" || e.Description != "Faktura 100: Demo kunde" {
+		t.Errorf("header = %+v", e)
+	}
+}
+
+func TestBuildReportsUnmapped(t *testing.T) {
+	_, err := config().Build(voucher(
+		multicase.Line{Account: "9999", Amount: -100},
+		multicase.Line{Account: "1460", Amount: 100, VATCode: "42"},
+	))
+	var u *UnmappedError
+	if !errors.As(err, &u) || len(u.Accounts) != 1 || u.Accounts[0] != "9999" || len(u.VATCodes) != 1 || u.VATCodes[0] != "42" {
+		t.Fatalf("err = %v", err)
+	}
+}
+
+func TestBuildRounding(t *testing.T) {
+	e, err := config().Build(voucher(
+		multicase.Line{Account: "1460", Amount: 1978734},
+		multicase.Line{Account: "4301", Amount: -1832162},
+		multicase.Line{Account: "4301", Amount: -146573},
+	))
+	if err != nil {
+		t.Fatal(err)
+	}
+	last := e.Lines[len(e.Lines)-1]
+	if last.Account != "3740" || last.Debit != 1 {
+		t.Errorf("rounding line = %+v", last)
+	}
+
+	_, err = config().Build(voucher(
+		multicase.Line{Account: "1460", Amount: 1000},
+		multicase.Line{Account: "4301", Amount: -500},
+	))
+	if err == nil {
+		t.Error("expected an error for a voucher off by more than max_rounding_ore")
+	}
+}
+
+func TestBuildSkipsZeroLines(t *testing.T) {
+	_, err := config().Build(voucher(multicase.Line{Account: "20001", Amount: 0, CustomerNo: "20001"}))
+	if !errors.Is(err, ErrEmpty) {
+		t.Fatalf("err = %v, want ErrEmpty", err)
+	}
+}