feat: Indicate in metadata which client info properties are supported…

…. [metadata]

Signed-off-by: Michael Simons <[email protected]>

neo4j-jdbc/src/main/java/org/neo4j/jdbc/ConnectionImpl.java

@@ -577,7 +577,7 @@ private void setClientInfo0(String name, String value) throws SQLWarning {
 			var throwable = new SQLClientInfoException(Map.of("", ClientInfoStatus.REASON_UNKNOWN));
 			throw new SQLWarning("Client information without a name are not supported", throwable);
 		}
-		if (!Set.of("ApplicationName", "ClientUser", "ClientHostname").contains(name)) {
+		if (!DatabaseMetadataImpl.isSupportedClientInfoProperty(name)) {
 			var throwable = new SQLClientInfoException(Map.of(name, ClientInfoStatus.REASON_UNKNOWN_PROPERTY));
 			throw new SQLWarning("Unknown client info property `" + name + "`", throwable);
 		}

neo4j-jdbc/src/main/java/org/neo4j/jdbc/DatabaseMetadataImpl.java

@@ -97,6 +97,13 @@ final class DatabaseMetadataImpl implements DatabaseMetaData {
 	private static final List<String> TIME_DATE_FUNCTIONS = List.of("date", "datetime", "localdatetime", "localtime",
 			"time", "duration");
 
+	private static final List<ClientInfoProperty> SUPPORTED_CLIENT_INFO_PROPERTIES = List.of(
+			new ClientInfoProperty("ApplicationName", "The name of the application currently utilizing the connection"),
+			new ClientInfoProperty("ClientUser",
+					"The name of the user that the application using the connection is performing work for"),
+			new ClientInfoProperty("ClientHostname",
+					"The hostname of the computer the application using the connection is running on"));
+
 	private static final Logger LOGGER = Logger.getLogger(DatabaseMetadataImpl.class.getCanonicalName());
 
 	private final Connection connection;
@@ -1476,8 +1483,22 @@ public boolean autoCommitFailureClosesAllResultSets() throws SQLException {
 	}
 
 	@Override
-	public ResultSet getClientInfoProperties() throws SQLException {
-		throw new SQLFeatureNotSupportedException();
+	public ResultSet getClientInfoProperties() {
+
+		var keys = List.of("NAME", "MAX_LEN", "DEFAULT_VALUE", "DESCRIPTION");
+		var values = new ArrayList<Value[]>();
+		for (var property : SUPPORTED_CLIENT_INFO_PROPERTIES) {
+			values.add(new Value[] { Values.value(property.name()), Values.value(65536), Values.NULL,
+					Values.value(property.description()) });
+		}
+		var response = createRunResponseForStaticKeys(keys);
+		var pull = staticPullResponseFor(keys, values);
+
+		return new ResultSetImpl(new LocalStatementImpl(), new ThrowingTransactionImpl(), response, pull, -1, -1, -1);
+	}
+
+	static boolean isSupportedClientInfoProperty(String name) {
+		return SUPPORTED_CLIENT_INFO_PROPERTIES.stream().anyMatch(p -> p.name().equals(name));
 	}
 
 	@Override
@@ -1640,4 +1661,7 @@ private record QueryAndRunResponse(PullResponse pullResponse, CompletableFuture<
 	private record UniqueConstraint(String name, List<String> labelsOrTypes, List<String> properties) {
 	}
 
+	private record ClientInfoProperty(String name, String description) {
+	}
+
 }

neo4j-jdbc/src/test/java/org/neo4j/jdbc/DatabaseMetadataImplTests.java

@@ -238,6 +238,31 @@ void getTypeInfoShouldWork() throws SQLException {
 		}
 	}
 
+	@Test
+	void getClientInfoPropertiesShouldWork() throws SQLException {
+		var connection = newConnection();
+		var maxLen = (int) Math.pow(2, 16);
+		try (var rs = connection.getMetaData().getClientInfoProperties()) {
+			assertThat(rs.next()).isTrue();
+			assertThat(rs.getString("NAME")).isEqualTo("ApplicationName");
+			assertThat(rs.getInt("MAX_LEN")).isEqualTo(maxLen);
+			assertThat(rs.getString("DEFAULT_VALUE")).isNull();
+			assertThat(rs.getString("DESCRIPTION")).isNotNull();
+			assertThat(rs.next()).isTrue();
+			assertThat(rs.getString("NAME")).isEqualTo("ClientUser");
+			assertThat(rs.getInt("MAX_LEN")).isEqualTo(maxLen);
+			assertThat(rs.getString("DESCRIPTION")).isNotNull();
+			assertThat(rs.next()).isTrue();
+			assertThat(rs.getString("NAME")).isEqualTo("ClientHostname");
+			assertThat(rs.getInt("MAX_LEN")).isEqualTo(maxLen);
+			assertThat(rs.getString("DESCRIPTION")).isNotNull();
+			assertThat(rs.next()).isFalse();
+		}
+
+		connection.setClientInfo("ApplicationName", "a unit test");
+		assertThat(connection.getClientInfo("ApplicationName")).isEqualTo("a unit test");
+	}
+
 	private Connection newConnection() throws SQLException {
 		var url = "jdbc:neo4j://host";