test(sql): live SQL Server gate for the row cap (R06:S-1)

An events table with 40 rows for one where-pair selector: the capped SELECT TOP (2) runs as real T-SQL, the ambiguous tag publishes BadConfigurationError, a single-row station reads Good through the same statement, and the driver stays Healthy. Live run 2026-10-22: SQL Server 22/22, Postgres 7/7 and Oracle 6/6 (LIMIT n / FETCH FIRST n ROWS ONLY after WHERE) all green on 10.100.0.35. Refs #744 Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
2026-10-22 16:10:12 -04:00
parent 2a28c06fc7
commit a7506e7ed4
1 changed files with 58 additions and 0 deletions
@@ -58,6 +58,64 @@ public sealed class SqlServerReadTests
        driver.GetHostStatuses().ShouldHaveSingleItem().State.ShouldBe(HostState.Running);
    }

+    // ---- R06:S-1: the row cap, on real T-SQL ----
+
+    /// <summary>
+    ///     A where-pair selector pointed at an events table (40 rows for one station) used to pull every
+    ///     matching row on every poll. The plan now emits <c>SELECT TOP (2) …</c> — proven valid T-SQL here —
+    ///     and the second row makes the tag publish <c>BadConfigurationError</c> while the driver stays
+    ///     Healthy (the server answered). The positive control: a station with exactly one row reads Good
+    ///     through the same capped statement.
+    /// </summary>
+    [Fact]
+    public async Task ReadAsync_realSqlServer_anAmbiguousSelectorIsRowCappedToAConfigurationError()
+    {
+        SkipUnlessLive();
+        const string table = "RowCapEvents";
+
+        await using (var arrange = await _sql.OpenInspectionConnectionAsync())
+        {
+            await using var command = arrange.CreateCommand();
+            command.CommandText = string.Create(CultureInfo.InvariantCulture, $"""
+                IF OBJECT_ID(N'{SqlPollServerFixture.Schema}.{table}') IS NOT NULL DROP TABLE {SqlPollServerFixture.Schema}.{table};
+                CREATE TABLE {SqlPollServerFixture.Schema}.{table} (
+                    {SqlPollServerFixture.WideRowSelectorColumn} int NOT NULL,
+                    oven_temp float NULL,
+                    {SqlPollServerFixture.TimestampColumn} datetime2 NOT NULL);
+                INSERT INTO {SqlPollServerFixture.Schema}.{table} VALUES (1, 21.5, '2026-07-24T10:00:00');
+                DECLARE @i int = 0;
+                WHILE @i < 40
+                BEGIN
+                    INSERT INTO {SqlPollServerFixture.Schema}.{table} VALUES (7, @i, DATEADD(second, @i, '2026-07-24T10:00:00'));
+                    SET @i += 1;
+                END
+                """);
+            await command.ExecuteNonQueryAsync(TestContext.Current.CancellationToken);
+        }
+
+        try
+        {
+            await using var driver = await StartAsync(
+                WideRowWhere("Sql/Events/Ambiguous", "oven_temp", "7", table),
+                WideRowWhere("Sql/Events/Clean", "oven_temp", "1", table));
+
+            var snapshots = await driver.ReadAsync(
+                ["Sql/Events/Ambiguous", "Sql/Events/Clean"], TestContext.Current.CancellationToken);
+
+            snapshots[0].StatusCode.ShouldBe(SqlStatusCodes.BadConfigurationError);
+            snapshots[1].StatusCode.ShouldBe(SqlStatusCodes.Good);
+            Convert.ToDouble(snapshots[1].Value).ShouldBe(21.5);
+            driver.GetHealth().State.ShouldBe(DriverState.Healthy);
+        }
+        finally
+        {
+            await using var cleanup = await _sql.OpenInspectionConnectionAsync();
+            await using var drop = cleanup.CreateCommand();
+            drop.CommandText = $"DROP TABLE IF EXISTS {SqlPollServerFixture.Schema}.{table}";
+            await drop.ExecuteNonQueryAsync(CancellationToken.None);
+        }
+    }
+
    // ---- key-value model ----

    /// <summary>The plan's headline case: a seeded key-value row round-trips as a Good snapshot.</summary>