add post transactions endpoint

server.go

@@ -22,6 +22,8 @@ func (server Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	switch r.Method + r.URL.Path {
 	case "GET/api/transactions":
 		server.getTransactions(w, r)
+	case "POST/api/transactions":
+		server.postTransactions(w, r)
 	case "PUT/api/transactions":
 		server.putTransactions(w, r)
 	case "GET/api/balances":
@@ -50,6 +52,30 @@ func (server Server) getTransactions(w http.ResponseWriter, r *http.Request) {
 	json.NewEncoder(w).Encode(map[string]interface{}{"Transactions": transactions})
 }
 
+func (server Server) postTransactions(w http.ResponseWriter, r *http.Request) {
+	var request struct {
+		Transaction
+	}
+	if err := json.NewDecoder(r.Body).Decode(&request); err != nil {
+		server.err(w, r, err)
+		return
+	}
+	if err := server.ledger.NewTransaction(); err != nil {
+		server.err(w, r, err)
+		return
+	}
+	transactions, err := server.ledger.Transactions()
+	if err != nil {
+		server.err(w, r, err)
+		return
+	}
+	if err := server.ledger.SetTransaction(len(transactions)-1, request.Transaction); err != nil {
+		server.err(w, r, err)
+		return
+	}
+	json.NewEncoder(w).Encode(map[string]interface{}{"ok": true})
+}
+
 func (server Server) putTransactions(w http.ResponseWriter, r *http.Request) {
 	var request struct {
 		IDX int `json:"idx"`

server_test.go

@@ -0,0 +1,48 @@
+package main
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+)
+
+func TestServerPostTransactions(t *testing.T) {
+	path := testLedgerFile(t)
+	ledger, err := NewLedger(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	server := Server{ledger: ledger}
+
+	r := httptest.NewRequest(http.MethodPost, "/", strings.NewReader(`{
+      "Date": "2099-02-03",
+      "Description": "test",
+      "Payer": "payer",
+      "Payee": "payee",
+      "Amount": 1.02
+   }`))
+	w := httptest.NewRecorder()
+	server.postTransactions(w, r)
+
+	if w.Code != http.StatusOK {
+		t.Fatal(w.Code)
+	}
+	if s := strings.TrimSpace(string(w.Body.Bytes())); s != `{"ok":true}` {
+		t.Fatal(s)
+	}
+
+	transactions, err := ledger.Transactions()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if transactions[len(transactions)-1] != (Transaction{
+		Date:        "2099-02-03",
+		Description: "test",
+		Payer:       "payer",
+		Payee:       "payee",
+		Amount:      1.02,
+	}) {
+		t.Fatal(transactions[len(transactions)-1])
+	}
+}