fix(conformance): fail fast when the suite is not on libSQL

libsql-conformance/src/test/java/com/github/magnusp/libsql/conformance/LibsqlConformanceGuard.java

@@ -0,0 +1,73 @@
+package com.github.magnusp.libsql.conformance;
+
+import java.sql.Connection;
+import java.sql.DatabaseMetaData;
+import java.sql.DriverManager;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Statement;
+
+final class LibsqlConformanceGuard {
+
+    static final String EXPECTED_DRIVER_NAME = "libSQL JDBC Driver";
+    static final String EXPECTED_DATABASE_PRODUCT_NAME = "SQLite (libSQL)";
+    static final String LIBSQL_SOURCE_ID_SUFFIX = "alt1";
+
+    private static final String PROBE_URL = "jdbc:sqlite::memory:";
+
+    private LibsqlConformanceGuard() {}
+
+    static void verify() {
+        try (Connection connection = DriverManager.getConnection(PROBE_URL)) {
+            verify(connection);
+        } catch (SQLException e) {
+            throw new IllegalStateException(
+                    "Conformance suite could not obtain a JDBC connection from " + PROBE_URL, e);
+        }
+    }
+
+    static void verify(Connection connection) throws SQLException {
+        DatabaseMetaData metadata = connection.getMetaData();
+        String driverName = metadata.getDriverName();
+        String productName = metadata.getDatabaseProductName();
+
+        if (!EXPECTED_DRIVER_NAME.equals(driverName)
+                || !EXPECTED_DATABASE_PRODUCT_NAME.equals(productName)) {
+            throw new AssertionError(
+                    "Conformance suite is not connected to libSQL: expected driver \""
+                            + EXPECTED_DRIVER_NAME
+                            + "\" and database product \""
+                            + EXPECTED_DATABASE_PRODUCT_NAME
+                            + "\", but resolved driver \""
+                            + driverName
+                            + "\" and database product \""
+                            + productName
+                            + "\"");
+        }
+
+        String sourceId = readSourceId(connection);
+        if (sourceId == null || !sourceId.endsWith(LIBSQL_SOURCE_ID_SUFFIX)) {
+            throw new AssertionError(
+                    "Conformance suite is not connected to a libSQL server: expected SQLite"
+                            + " source id ending \""
+                            + LIBSQL_SOURCE_ID_SUFFIX
+                            + "\", but resolved \""
+                            + sourceId
+                            + "\" through driver \""
+                            + driverName
+                            + "\"");
+        }
+    }
+
+    private static String readSourceId(Connection connection) throws SQLException {
+        try (Statement statement = connection.createStatement();
+                ResultSet resultSet = statement.executeQuery("SELECT sqlite_source_id()")) {
+            if (!resultSet.next()) {
+                throw new AssertionError(
+                        "Conformance suite could not read a SQLite source id from "
+                                + "the libSQL connection");
+            }
+            return resultSet.getString(1);
+        }
+    }
+}

libsql-conformance/src/test/java/com/github/magnusp/libsql/conformance/LibsqlConformanceGuardTest.java

@@ -0,0 +1,108 @@
+package com.github.magnusp.libsql.conformance;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Proxy;
+import java.sql.Connection;
+import java.sql.DatabaseMetaData;
+import java.sql.ResultSet;
+import java.sql.Statement;
+import org.junit.jupiter.api.Test;
+
+class LibsqlConformanceGuardTest {
+
+    @Test
+    void acceptsALibsqlConnection() throws Exception {
+        Connection connection =
+                connection(
+                        "libSQL JDBC Driver",
+                        "SQLite (libSQL)",
+                        "2024-10-21 16:30:22 03a9703e27c44437c39363d0baf82db4ebc94538a0f284"
+                                + "11c85dda156f82alt1");
+
+        LibsqlConformanceGuard.verify(connection);
+    }
+
+    @Test
+    void rejectsAForeignDriverAndNamesTheResolvedAndExpectedDriver() {
+        Connection connection = connection("SQLite JDBC", "SQLite", null);
+
+        AssertionError failure =
+                assertThrows(
+                        AssertionError.class, () -> LibsqlConformanceGuard.verify(connection));
+
+        assertThat(failure)
+                .hasMessageContaining("\"SQLite JDBC\"")
+                .hasMessageContaining("\"libSQL JDBC Driver\"");
+    }
+
+    @Test
+    void rejectsANonLibsqlServerAndNamesTheResolvedSourceId() {
+        Connection connection =
+                connection(
+                        "libSQL JDBC Driver",
+                        "SQLite (libSQL)",
+                        "2024-10-21 16:30:22 03a9703e27c44437c39363d0baf82db4ebc94538a0f284"
+                                + "11c85dda156f82");
+
+        AssertionError failure =
+                assertThrows(
+                        AssertionError.class, () -> LibsqlConformanceGuard.verify(connection));
+
+        assertThat(failure)
+                .hasMessageContaining("2024-10-21 16:30:22")
+                .hasMessageContaining("alt1");
+    }
+
+    private static Connection connection(
+            String driverName, String productName, String sourceId) {
+        ResultSet resultSet =
+                proxy(
+                        ResultSet.class,
+                        (proxy, method, args) ->
+                                switch (method.getName()) {
+                                    case "next" -> true;
+                                    case "getString" -> sourceId;
+                                    case "close" -> null;
+                                    default -> unsupported(method.getName());
+                                });
+        Statement statement =
+                proxy(
+                        Statement.class,
+                        (proxy, method, args) ->
+                                switch (method.getName()) {
+                                    case "executeQuery" -> resultSet;
+                                    case "close" -> null;
+                                    default -> unsupported(method.getName());
+                                });
+        DatabaseMetaData metadata =
+                proxy(
+                        DatabaseMetaData.class,
+                        (proxy, method, args) ->
+                                switch (method.getName()) {
+                                    case "getDriverName" -> driverName;
+                                    case "getDatabaseProductName" -> productName;
+                                    default -> unsupported(method.getName());
+                                });
+        return proxy(
+                Connection.class,
+                (proxy, method, args) ->
+                        switch (method.getName()) {
+                            case "getMetaData" -> metadata;
+                            case "createStatement" -> statement;
+                            case "close" -> null;
+                            default -> unsupported(method.getName());
+                        });
+    }
+
+    private static Object unsupported(String methodName) {
+        throw new UnsupportedOperationException(methodName);
+    }
+
+    @SuppressWarnings("unchecked")
+    private static <T> T proxy(Class<T> type, InvocationHandler handler) {
+        return (T) Proxy.newProxyInstance(type.getClassLoader(), new Class<?>[] {type}, handler);
+    }
+}

libsql-conformance/src/test/java/com/github/magnusp/libsql/conformance/XerialLauncherSessionListener.java

@@ -8,6 +8,7 @@ public final class XerialLauncherSessionListener implements LauncherSessionListe
     @Override
     public void launcherSessionOpened(LauncherSession session) {
         XerialConformanceDriver.register();
+        LibsqlConformanceGuard.verify();
     }
 
     @Override