Introduce transaction generic helpers

Relates to #373

neo4j/transaction_helpers.go

@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) "Neo4j"
+ * Neo4j Sweden AB [https://neo4j.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package neo4j
+
+import "context"
+
+type ManagedTransactionWorkT[T any] func(tx ManagedTransaction) (T, error)
+
+func ExecuteRead[T any](ctx context.Context, session SessionWithContext,
+	work ManagedTransactionWorkT[T],
+	configurers ...func(config *TransactionConfig)) (T, error) {
+
+	return castGeneric[T](session.ExecuteRead(ctx, transactionWorkAdapter(work), configurers...))
+}
+
+func ExecuteWrite[T any](ctx context.Context, session SessionWithContext,
+	work ManagedTransactionWorkT[T],
+	configurers ...func(config *TransactionConfig)) (T, error) {
+
+	return castGeneric[T](session.ExecuteWrite(ctx, transactionWorkAdapter(work), configurers...))
+}
+
+func transactionWorkAdapter[T any](work ManagedTransactionWorkT[T]) ManagedTransactionWork {
+	return func(tx ManagedTransaction) (any, error) {
+		return work(tx)
+	}
+}
+
+func castGeneric[T any](result any, err error) (T, error) {
+	if err != nil {
+		return *new(T), err
+	}
+	return result.(T), nil
+}

neo4j/transaction_helpers_test.go

@@ -0,0 +1,134 @@
+/*
+ * Copyright (c) "Neo4j"
+ * Neo4j Sweden AB [https://neo4j.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package neo4j_test
+
+import (
+	"context"
+	"fmt"
+	"github.com/neo4j/neo4j-go-driver/v5/neo4j"
+	. "github.com/neo4j/neo4j-go-driver/v5/neo4j/internal/testutil"
+	"testing"
+)
+
+func TestExecuteRead(outer *testing.T) {
+	outer.Parallel()
+
+	ctx := context.Background()
+	session := &fakeSession{}
+
+	outer.Run("returns type-safe result from underlying session read execution", func(t *testing.T) {
+		result, err := neo4j.ExecuteRead[int](ctx, session, func(tx neo4j.ManagedTransaction) (int, error) {
+			return 42, nil
+		})
+
+		AssertNoError(t, err)
+		AssertIntEqual(t, result, 42)
+	})
+
+	outer.Run("returns underlying session read execution error", func(t *testing.T) {
+		result, err := neo4j.ExecuteRead[int](ctx, session, func(tx neo4j.ManagedTransaction) (int, error) {
+			return -1, fmt.Errorf("nope")
+		})
+
+		AssertErrorMessageContains(t, err, "nope")
+		AssertIntEqual(t, result, 0) // value is ignored - default is returned
+	})
+}
+
+func TestExecuteWrite(outer *testing.T) {
+	outer.Parallel()
+
+	ctx := context.Background()
+	session := &fakeSession{}
+
+	outer.Run("returns type-safe result from underlying session write execution", func(t *testing.T) {
+		result, err := neo4j.ExecuteWrite[string](ctx, session, func(tx neo4j.ManagedTransaction) (string, error) {
+			return "much wow", nil
+		})
+
+		AssertNoError(t, err)
+		AssertStringEqual(t, result, "much wow")
+	})
+
+	outer.Run("returns underlying session write execution error", func(t *testing.T) {
+		result, err := neo4j.ExecuteWrite[*struct{}](ctx, session, func(tx neo4j.ManagedTransaction) (*struct{}, error) {
+			return nil, fmt.Errorf("nope")
+		})
+
+		AssertErrorMessageContains(t, err, "nope")
+		AssertNil(t, result) // value is ignored - default is returned
+	})
+}
+
+type fakeSession struct {
+	neo4j.SessionWithContext
+}
+
+func (f *fakeSession) LastBookmarks() neo4j.Bookmarks {
+	panic("implement me")
+}
+
+//lint:ignore U1000 needed for interface adherence
+func (f *fakeSession) lastBookmark() string {
+	panic("implement me")
+}
+
+func (f *fakeSession) BeginTransaction(ctx context.Context, configurers ...func(*neo4j.TransactionConfig)) (neo4j.ExplicitTransaction, error) {
+	panic("implement me")
+}
+
+func (f *fakeSession) ExecuteRead(_ context.Context, work neo4j.ManagedTransactionWork, _ ...func(*neo4j.TransactionConfig)) (any, error) {
+	return work(&FakeTransaction{})
+}
+
+func (f *fakeSession) ExecuteWrite(_ context.Context, work neo4j.ManagedTransactionWork, _ ...func(*neo4j.TransactionConfig)) (any, error) {
+	return work(&FakeTransaction{})
+}
+
+func (f *fakeSession) Run(context.Context, string, map[string]any, ...func(*neo4j.TransactionConfig)) (neo4j.ResultWithContext, error) {
+	panic("implement me")
+}
+
+func (f *fakeSession) Close(context.Context) error {
+	panic("implement me")
+}
+
+//lint:ignore U1000 needed for interface adherence
+func (f *fakeSession) legacy() neo4j.Session {
+	panic("implement me")
+}
+
+//lint:ignore U1000 needed for interface adherence
+func (f *fakeSession) getServerInfo(ctx context.Context) (neo4j.ServerInfo, error) {
+	panic("implement me")
+}
+
+type FakeTransaction struct {
+	neo4j.ManagedTransaction
+}
+
+func (f *FakeTransaction) Run(ctx context.Context, cypher string, params map[string]any) (neo4j.ResultWithContext, error) {
+	panic("implement me")
+}
+
+//lint:ignore U1000 needed for interface adherence
+func (f *FakeTransaction) legacy() neo4j.Transaction {
+	panic("implement me")
+}