ledger.newtransaction

ledger.go

@@ -8,6 +8,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path"
+	"time"
 )
 
 type Ledger struct {
@@ -24,6 +25,21 @@ func NewLedger(path string) (Ledger, error) {
 	}, err
 }
 
+func (ledger Ledger) NewTransaction() error {
+	transactions, err := ledger.Transactions()
+	if err != nil {
+		return err
+	}
+	transactions = append(transactions, Transaction{
+		Date:        time.Now().Format("2006-01-02"),
+		Description: "?",
+		Payer:       "?",
+		Payee:       "?",
+		Amount:      0,
+	})
+	return ledger.SetTransactions(transactions)
+}
+
 func (ledger Ledger) SetTransaction(i int, transaction Transaction) error {
 	transactions, err := ledger.Transactions()
 	if err != nil {

ledger_test.go

@@ -2,7 +2,7 @@ package main
 
 import (
 	"fmt"
-	"io"
+	"io/ioutil"
 	"os"
 	"path"
 	"testing"
@@ -10,8 +10,19 @@ import (
 	"github.com/google/uuid"
 )
 
+func testLedgerFile(t *testing.T) string {
+	path := path.Join(t.TempDir(), t.Name()+".dat")
+	if b, err := ioutil.ReadFile("./testdata/ledger.dat"); err != nil {
+		t.Fatal(err)
+	} else if err := ioutil.WriteFile(path, b, os.ModePerm); err != nil {
+		t.Fatal(err)
+	}
+	return path
+}
+
 func TestLedgerTransactionsBalances(t *testing.T) {
-	ledger, err := NewLedger("./testdata/ledger.dat")
+	path := testLedgerFile(t)
+	ledger, err := NewLedger(path)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -67,21 +78,7 @@ func TestLedgerSetTransaction(t *testing.T) {
 			Amount:      1.23,
 		}
 	}
-	path := path.Join(t.TempDir(), "ledger.dat")
-	a, err := os.Open("./testdata/ledger.dat")
-	if err != nil {
-		t.Fatal(err)
-	}
-	b, err := os.Create(path)
-	if err != nil {
-		t.Fatal(err)
-	}
-	if _, err := io.Copy(b, a); err != nil {
-		t.Fatal(err)
-	}
-	a.Close()
-	b.Close()
-
+	path := testLedgerFile(t)
 	ledger, err := NewLedger(path)
 	if err != nil {
 		t.Fatal(err)
@@ -109,3 +106,27 @@ func TestLedgerSetTransaction(t *testing.T) {
 		t.Fatal(want, got)
 	}
 }
+
+func TestLedgerNewTransaction(t *testing.T) {
+	path := testLedgerFile(t)
+	ledger, err := NewLedger(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	transactions, err := ledger.Transactions()
+	if err != nil {
+		t.Fatal(err)
+	}
+	wantTransactions := append(transactions, newStubTransaction())
+	ledger.NewTransaction()
+	if err != nil {
+		t.Fatal(err)
+	}
+	gotTransactions, err := ledger.Transactions()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if fmt.Sprint(wantTransactions) != fmt.Sprint(gotTransactions) {
+		t.Fatal(wantTransactions, gotTransactions)
+	}
+}

transaction.go

@@ -8,6 +8,7 @@ import (
 	"io"
 	"strconv"
 	"strings"
+	"time"
 )
 
 type Transaction struct {
@@ -18,6 +19,20 @@ type Transaction struct {
 	Amount      float32
 }
 
+const (
+	UnknownAccount = "?"
+)
+
+func newStubTransaction() Transaction {
+	return Transaction{
+		Date:        time.Now().Format("2006-01-02"),
+		Description: UnknownAccount,
+		Payer:       UnknownAccount,
+		Payee:       UnknownAccount,
+		Amount:      0,
+	}
+}
+
 func readTransaction(r io.Reader) (Transaction, error) {
 	lines := make([][]byte, 3)
 	for i := range lines {

transaction_test.go

@@ -6,6 +6,24 @@ import (
 	"testing"
 )
 
+func TestNewStubTransaction(t *testing.T) {
+	want := Transaction{
+		Date:        "1",
+		Amount:      0,
+		Payer:       UnknownAccount,
+		Payee:       UnknownAccount,
+		Description: UnknownAccount,
+	}
+	got := newStubTransaction()
+	if got.Date == "" {
+		t.Fatal(got.Date)
+	}
+	got.Date = want.Date
+	if want != got {
+		t.Fatal(want, got)
+	}
+}
+
 func TestWords(t *testing.T) {
 	input := `
       hello world