Support modifying a transaction category

through the PUT /transactions/{transactionId} method.
The category is also returned on a /transaction(s) call.

Restrict the PUT to changing only the category. The other existing
attributes should remain immutable.
Remove the body of the PUT response, it isn't required, and it was
returning a 204, which shouldn't have it.

This patch also extracts the CategoryName as a separate component on the
OpenAPI spec, so that it can be reused on the Transaction.

Issues #26 and #23

internal/dal/impl.go

@@ -20,7 +20,15 @@ func (dal *DalImpl) Transaction(transactionId int64) (*entity.Transaction, error
 		log.Panic("database not available")
 	}
 
-	rows, err := dal.Db.Query("SELECT t.id, t.date, t.description, t.amount FROM pfbudget.transactions t WHERE t.id = $1", transactionId)
+	stmt := `
+	SELECT t.id, t.date, t.description, t.amount, tc.name
+	FROM pfbudget.transactions t
+	LEFT JOIN pfbudget.transactions_categorized tc
+	ON t.id = tc.id
+	WHERE t.id = $1
+	`
+
+	rows, err := dal.Db.Query(stmt, transactionId)
 	if err != nil {
 		return nil, err
 	}
@@ -40,7 +48,14 @@ func (dal *DalImpl) Transactions() (entity.Transactions, error) {
 		log.Panic("database not available")
 	}
 
-	rows, err := dal.Db.Query("SELECT t.id, t.date, t.description, t.amount FROM pfbudget.transactions t")
+	stmt := `
+	SELECT t.id, t.date, t.description, t.amount, tc.name
+	FROM pfbudget.transactions t
+	LEFT JOIN pfbudget.transactions_categorized tc
+	ON t.id = tc.id
+	`
+
+	rows, err := dal.Db.Query(stmt)
 	if err != nil {
 		return entity.Transactions{}, err
 	}

internal/dal/impl_test.go

@@ -26,27 +26,38 @@ func TestDalImpl_Transaction(t *testing.T) {
 	}
 	type args struct {
 		transactionId int64
-		rows          [][]driver.Value
 	}
 	tests := []struct {
 		name    string
 		fields  fields
 		args    args
+		mocks   [][]driver.Value
 		want    *entity.Transaction
 		wantErr bool
 	}{
 		{
-			"200",
+			"SelectTransaction",
 			fields{db},
-			args{
+			args{1},
-				1,
+			[][]driver.Value{
-				[][]driver.Value{
+				{1, date, "income", 1000, nil},
-					{1, date, "income", 1000},
+			},
-				}},
 			&entity.Transaction{Id: 1, Date: date, Description: "income", Value: decimal.NewFromInt(1000)},
 			false,
 		},
-		{"404", fields{db}, args{2, nil}, nil, false},
+		{
+			"SelectTransactionWithCategory",
+			fields{db},
+			args{1},
+			[][]driver.Value{
+				{1, date, "income", 1000, "C1"},
+			},
+			&entity.Transaction{Id: 1, Date: date, Description: "income", Value: decimal.NewFromInt(1000), Category: golang.Ptr("C1")},
+			false,
+		},
+		{
+			"SelectNoTransaction", fields{db}, args{2}, nil, nil, false,
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -55,12 +66,15 @@ func TestDalImpl_Transaction(t *testing.T) {
 			}
 
 			mock.
-				ExpectQuery("^SELECT .* FROM .*transactions t WHERE t.id = \\$1$").
+				ExpectQuery(`
+					^SELECT \w+\.id, \w+\.date, \w+\.description, \w+\.amount, \w+\.name
+					FROM \w+\.transactions \w+
+					LEFT JOIN \w+\.transactions_categorized \w+
+					ON \w+\.id = \w+\.id
+					WHERE \w+\.id = \$1$`).
 				WithArgs(tt.args.transactionId).
 				WillReturnRows(
-					mock.
+					mock.NewRows([]string{"id", "date", "description", "amount", "category"}).AddRows(tt.mocks...),
-						NewRows([]string{"id", "date", "description", "amount"}).
-						AddRows(tt.args.rows...),
 				)
 
 			got, err := d.Transaction(tt.args.transactionId)
@@ -85,30 +99,42 @@ func TestDalImpl_Transactions(t *testing.T) {
 	type fields struct {
 		Db *sql.DB
 	}
-	type args struct {
-		rows [][]driver.Value
-	}
 	tests := []struct {
 		name    string
 		fields  fields
-		args    args
+		mocks   [][]driver.Value
 		want    entity.Transactions
 		wantErr bool
 	}{
 		{
-			"200",
+			"SelectTransactions",
 			fields{db},
-			args{[][]driver.Value{
+			[][]driver.Value{
-				{1, date, "income", 1000},
+				{1, date, "income", 1000, nil},
-				{2, date, "expense", -10.50},
+				{2, date, "expense", -10.50, nil},
-			}},
+			},
 			entity.Transactions{
 				{Id: 1, Date: date, Description: "income", Value: decimal.NewFromInt(1000)},
 				{Id: 2, Date: date, Description: "expense", Value: decimal.NewFromFloat(-10.50)},
 			},
 			false,
 		},
-		{"204", fields{db}, args{}, nil, false},
+		{
+			"SelectTransactionsWithCategory",
+			fields{db},
+			[][]driver.Value{
+				{1, date, "income", 1000, "C1"},
+				{2, date, "expense", -10.50, nil},
+			},
+			entity.Transactions{
+				{Id: 1, Date: date, Description: "income", Value: decimal.NewFromInt(1000), Category: golang.Ptr("C1")},
+				{Id: 2, Date: date, Description: "expense", Value: decimal.NewFromFloat(-10.50)},
+			},
+			false,
+		},
+		{
+			"SelectNoTransactions", fields{db}, nil, nil, false,
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -117,12 +143,14 @@ func TestDalImpl_Transactions(t *testing.T) {
 			}
 
 			mock.
-				ExpectQuery("^SELECT .* FROM .*transactions t$").
+				ExpectQuery(`
+					^SELECT \w+\.id, \w+\.date, \w+\.description, \w+\.amount, \w+\.name
+					FROM \w+\.transactions \w+
+					LEFT JOIN \w+\.transactions_categorized \w+
+					ON \w+\.id = \w+\.id`).
 				WithoutArgs().
 				WillReturnRows(
-					mock.
+					mock.NewRows([]string{"id", "date", "description", "amount", "category"}).AddRows(tt.mocks...),
-						NewRows([]string{"id", "date", "description", "amount"}).
-						AddRows(tt.args.rows...),
 				)
 
 			got, err := dal.Transactions()