using System;
using Npgsql;
var connectionString = Environment.GetEnvironmentVariable("NPGSQL_TEST_DB")
?? "Server=localhost;Username=npgsql_tests;Password=npgsql_tests;Database=npgsql_tests;Timeout=0;Command Timeout=0";
var dataSourceBuilder = new NpgsqlSlimDataSourceBuilder(connectionString);
await using var dataSource = dataSourceBuilder.Build();
await using var conn = dataSource.CreateConnection();
await conn.OpenAsync();
await using var cmd = new NpgsqlCommand("SELECT 'Hello World'", conn);
await using var reader = await cmd.ExecuteReaderAsync();
if (!await reader.ReadAsync())
throw new Exception("Got nothing from the database");
var value = reader.GetFieldValue(0);
if (value != "Hello World")
throw new Exception($"Got {value} instead of the expected 'Hello World'");