Enhance Neo4j integration test configuration (#544)

- Add `getVersionFromDB` to `DbServer` for dynamic version detection
- Remove default version in `VersionOf` if empty
- Default `GetDbServer` to localhost when `TEST_NEO4J_HOST` unset

neo4j/test-integration/dbserver/dbserver.go

@@ -23,11 +23,12 @@ package dbserver
 import (
 	"context"
 	"fmt"
-	"github.com/neo4j/neo4j-go-driver/v5/neo4j/config"
 	"os"
 	"strconv"
 	"sync"
 
+	"github.com/neo4j/neo4j-go-driver/v5/neo4j/config"
+
 	"github.com/neo4j/neo4j-go-driver/v5/neo4j"
 )
 
@@ -53,7 +54,7 @@ func GetDbServer(ctx context.Context) DbServer {
 
 	if server == nil {
 		vars := map[string]string{
-			"TEST_NEO4J_HOST":       "",
+			"TEST_NEO4J_HOST":       "localhost",
 			"TEST_NEO4J_USER":       "neo4j",
 			"TEST_NEO4J_PASS":       "password",
 			"TEST_NEO4J_SCHEME":     "neo4j",
@@ -62,15 +63,14 @@ func GetDbServer(ctx context.Context) DbServer {
 			"TEST_NEO4J_IS_CLUSTER": "0",
 			"TEST_NEO4J_VERSION":    "",
 		}
-		for k1, v1 := range vars {
-			v2, e2 := os.LookupEnv(k1)
-			if !e2 && v1 == "" {
-				panic(fmt.Sprintf("Required environment variable %s is missing", k1))
-			}
-			if e2 {
-				vars[k1] = v2
+
+		for k := range vars {
+			if envVal, exists := os.LookupEnv(k); exists {
+				vars[k] = envVal
+				fmt.Printf("Using %s=%s from environment\n", k, envVal)
 			}
 		}
+
 		key := "TEST_NEO4J_PORT"
 		port, err := strconv.ParseUint(vars[key], 10, 16)
 		if err != nil {
@@ -81,6 +81,7 @@ func GetDbServer(ctx context.Context) DbServer {
 		if err != nil {
 			panic(fmt.Sprintf("Unable to parse %s:%s to bool", key, vars[key]))
 		}
+
 		server = &DbServer{
 			Username:     vars["TEST_NEO4J_USER"],
 			Password:     vars["TEST_NEO4J_PASS"],
@@ -89,13 +90,62 @@ func GetDbServer(ctx context.Context) DbServer {
 			Port:         int(port),
 			IsCluster:    isCluster,
 			IsEnterprise: vars["TEST_NEO4J_EDITION"] == "enterprise",
-			Version:      VersionOf(vars["TEST_NEO4J_VERSION"]),
 		}
+
+		envVersion := VersionOf(vars["TEST_NEO4J_VERSION"])
+		setServerVersion(ctx, server, envVersion)
+
 		server.deleteData(ctx)
 	}
 	return *server
 }
 
+// setServerVersion assigns a specific Neo4j version to the DbServer instance.
+// It prefers the environment variable TEST_NEO4J_VERSION when available.
+// Otherwise, it queries the database to determine the version.
+// Panics if neither method can set the version, signaling the need for TEST_NEO4J_VERSION.
+func setServerVersion(ctx context.Context, server *DbServer, envVersion Version) {
+	if envVersion != noVersion {
+		server.Version = envVersion
+	} else {
+		version, err := server.getVersionFromDB(ctx)
+		if err != nil {
+			panic("Unable to determine version from database, please set the TEST_NEO4J_VERSION environment variable")
+		}
+		server.Version = version
+	}
+}
+
+// getVersionFromDB fetches the Neo4j database version.
+// this is used when the TEST_NEO4J_VERSION environment variable is not set.
+func (s *DbServer) getVersionFromDB(ctx context.Context) (Version, error) {
+	driver := s.Driver()
+	session := driver.NewSession(ctx, neo4j.SessionConfig{AccessMode: neo4j.AccessModeRead})
+	defer session.Close(ctx)
+
+	result, err := session.Run(ctx, "CALL dbms.components() YIELD versions UNWIND versions AS version RETURN version;", nil)
+	if err != nil {
+		return defaultVersion, err
+	}
+
+	record, err := result.Single(ctx)
+	if err != nil {
+		return defaultVersion, err
+	}
+
+	versionValue, found := record.Get("version")
+	if !found {
+		return defaultVersion, fmt.Errorf("version not found in record")
+	}
+
+	versionString, ok := versionValue.(string)
+	if !ok {
+		return defaultVersion, fmt.Errorf("version is not a string")
+	}
+
+	return VersionOf(versionString), nil
+}
+
 func (s DbServer) deleteData(ctx context.Context) {
 	driver := s.Driver()
 	session := driver.NewSession(ctx, neo4j.SessionConfig{AccessMode: neo4j.AccessModeWrite})

neo4j/test-integration/dbserver/version.go

@@ -46,19 +46,15 @@ var (
 )
 
 func VersionOf(server string) Version {
-	if server == "" {
-		return defaultVersion
-	} else {
-		if versionMatcher == nil {
-			versionMatcher = regexp.MustCompile(versionPattern)
-		}
-		matches := versionMatcher.FindStringSubmatch(server)
-		if matches != nil {
-			major, _ := strconv.Atoi(matches[2])
-			minor := parseMinor(matches[3])
-			patch, _ := strconv.Atoi(matches[4])
-			return Version{major, minor, patch}
-		}
+	if versionMatcher == nil {
+		versionMatcher = regexp.MustCompile(versionPattern)
+	}
+	matches := versionMatcher.FindStringSubmatch(server)
+	if matches != nil {
+		major, _ := strconv.Atoi(matches[2])
+		minor := parseMinor(matches[3])
+		patch, _ := strconv.Atoi(matches[4])
+		return Version{major, minor, patch}
 	}
 
 	return noVersion