AG reads: share one floor-bounded newest-snapshot read across Viewer and Service (#4228)

Darling/Darling.Tests/AvailabilityGroupCountReadTests.cs

@@ -31,7 +31,7 @@ public sealed class AvailabilityGroupCountReadTests
     private static string? ConnectionString => Environment.GetEnvironmentVariable("DARLING_TEST_PG");
 
     /// <summary>Plants TWO distinct AGs under one server, so a count/topology pair that "agree" by both
-    /// landing on 0 or both landing on 1 does not pass this — <see cref="DarlingAgReader.AvailabilityGroupCountSql"/>'s
+    /// landing on 0 or both landing on 1 does not pass this — <see cref="PerformanceMonitor.Darling.Storage.DarlingAgStatesReader.ReplicaGroupCountSql"/>'s
     /// doc explains why the database grain and the ORDER BY the topology read carries cannot change the
     /// number either read reports.</summary>
     [Fact]

Darling/Darling.Tests/DarlingAgReaderTests.cs

@@ -392,98 +392,8 @@ public void SerializedShape_CarriesTheFieldsBothConsumersRead()
         JsonAssert.DoesNotContain("\"severity\": 3", json);
     }
 
-    /* ─────────────────────────── SQL dialect pins ─────────────────────────── */
-
-    [Fact]
-    public void ReadSql_IsPostgresDialect_WithPositionalServerFilter()
-    {
-        foreach (var sql in new[] { Reader.ReplicaStatesSql, Reader.DatabaseReplicaStatesSql })
-        {
-            /* Positional params (Npgsql), never a named @param or an N'' literal. */
-            Assert.Contains("$1", sql, StringComparison.Ordinal);
-            Assert.DoesNotContain("@", sql, StringComparison.Ordinal);
-            Assert.DoesNotContain("N'", sql, StringComparison.Ordinal);
-
-            /* The filter guards BOTH the inner latest-instant aggregate and the outer read — count, don't just
-               Contains, or deleting either WHERE leaves this green. */
-            Assert.Equal(2, Occurrences(sql, "$1::integer IS NULL"));
-        }
-    }
-
-    private static int Occurrences(string haystack, string needle)
-    {
-        var count = 0;
-        for (var i = haystack.IndexOf(needle, StringComparison.Ordinal); i >= 0;
-             i = haystack.IndexOf(needle, i + needle.Length, StringComparison.Ordinal))
-        {
-            count++;
-        }
-
-        return count;
-    }
-
-    [Fact]
-    public void ReadSql_RestrictsToTheEnabledServerRegistry()
-    {
-        /* Every other fleet read joins the enabled registry; without it a server disabled in the control plane
-           keeps producing AG cards until its rows age out, after it has already left /api/fleet and the sidebar. */
-        foreach (var sql in new[] { Reader.ReplicaStatesSql, Reader.DatabaseReplicaStatesSql })
-        {
-            Assert.Contains("JOIN servers AS s", sql, StringComparison.Ordinal);
-            Assert.Contains("s.is_enabled", sql, StringComparison.Ordinal);
-        }
-    }
-
-    [Fact]
-    public void ReadSql_KeepsEveryRowAtEachServersNewestCollection()
-    {
-        /* DISTINCT ON would keep ONE row per server — which is exactly wrong here, since a snapshot is many rows
-           (one per replica / per database). The join against MAX(collection_time) keeps them all. */
-        foreach (var sql in new[] { Reader.ReplicaStatesSql, Reader.DatabaseReplicaStatesSql })
-        {
-            Assert.Contains("MAX(collection_time)", sql, StringComparison.Ordinal);
-            Assert.Contains("GROUP BY server_id", sql, StringComparison.Ordinal);
-            Assert.DoesNotContain("DISTINCT ON", sql, StringComparison.Ordinal);
-        }
-    }
-
-    [Fact]
-    public void ReadSql_SelectsIsLocalOnBothGrains()
-    {
-        /* V37 put is_local on the replica grain; V34 already had it on the database grain. Inserting it shifted
-           the replica read's ordinals, which is the classic silent mis-map. */
-        Assert.Contains("r.is_local", Reader.ReplicaStatesSql, StringComparison.Ordinal);
-        Assert.Contains("d.is_local", Reader.DatabaseReplicaStatesSql, StringComparison.Ordinal);
-    }
-
-    [Fact]
-    public void ReadSql_ReadsTheCollectQualifiedBaseTables()
-    {
-        /* Post-V14 collectors get no v_* passthrough view, so the readers name the base tables directly. */
-        Assert.Contains("FROM collect.ag_replica_states", Reader.ReplicaStatesSql, StringComparison.Ordinal);
-        Assert.Contains("FROM collect.ag_database_replica_states", Reader.DatabaseReplicaStatesSql, StringComparison.Ordinal);
-    }
-
-    [Fact]
-    public void ReadSql_SelectsEveryColumnTheDtoSurfaces()
-    {
-        foreach (var column in new[]
-        {
-            "role_desc", "operational_state_desc", "connected_state_desc", "recovery_health_desc",
-            "synchronization_health_desc", "availability_mode_desc", "failover_mode_desc", "endpoint_url",
-        })
-        {
-            Assert.Contains(column, Reader.ReplicaStatesSql, StringComparison.Ordinal);
-        }
-
-        foreach (var column in new[]
-        {
-            "synchronization_state_desc", "last_hardened_lsn", "last_commit_lsn", "log_send_queue_size",
-            "redo_queue_size", "log_send_rate", "redo_rate", "is_suspended", "suspend_reason_desc",
-            "secondary_lag_seconds", "is_local",
-        })
-        {
-            Assert.Contains(column, Reader.DatabaseReplicaStatesSql, StringComparison.Ordinal);
-        }
-    }
+    /* The SQL dialect/shape pins used to live here, against this reader's own copy of the statement text. That
+       copy moved to DarlingAgStatesReaderTests (#4228) along with the statement text itself — see
+       DarlingAgStatesReader in PerformanceMonitor.Darling.Storage, now the one implementation ReadReplicasAsync
+       and ReadDatabasesAsync above map into this file's ReplicaRow / DatabaseRow. */
 }