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scadaproj/ZB.MOM.WW.LocalDb/tests/ZB.MOM.WW.LocalDb.Tests/SyncSessionTests.cs
T

597 lines
24 KiB
C#

using System.Threading.Channels;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.Abstractions;
using ZB.MOM.WW.LocalDb.Contracts;
using ZB.MOM.WW.LocalDb.Internal;
using ZB.MOM.WW.LocalDb.Replication;
using ZB.MOM.WW.LocalDb.Replication.Internal;
namespace ZB.MOM.WW.LocalDb.Tests;
public sealed class SyncSessionTests : IDisposable
{
private const string OrdersSql = "CREATE TABLE orders (id INTEGER PRIMARY KEY, sku TEXT, qty INTEGER)";
private static readonly TimeSpan RunTimeout = TimeSpan.FromSeconds(15);
private readonly List<string> _paths = [];
private readonly List<IDisposable> _disposables = [];
public void Dispose()
{
foreach (var d in _disposables)
d.Dispose();
Microsoft.Data.Sqlite.SqliteConnection.ClearAllPools();
foreach (var p in _paths)
{
if (File.Exists(p)) File.Delete(p);
if (File.Exists(p + "-wal")) File.Delete(p + "-wal");
if (File.Exists(p + "-shm")) File.Delete(p + "-shm");
}
}
private sealed record Side(
SqliteLocalDb Db, OplogStore Store, LwwApplier Applier, SyncSession Session);
private async Task<Side> NewSideAsync(
string createSql = OrdersSql,
string table = "orders",
ReplicationOptions? options = null,
ILogger? logger = null,
Func<DateTimeOffset>? utcNow = null)
{
var path = Path.Combine(Path.GetTempPath(), Guid.NewGuid() + ".db");
_paths.Add(path);
var db = new SqliteLocalDb(new LocalDbOptions { Path = path });
_disposables.Add(db);
await db.ExecuteAsync(createSql);
db.RegisterReplicated(table);
options ??= new ReplicationOptions { FlushInterval = TimeSpan.FromMilliseconds(20) };
var store = new OplogStore(db, options, utcNow);
var applier = new LwwApplier(db, utcNow);
var session = new SyncSession(db, store, applier, options, logger ?? NullLogger.Instance, utcNow);
return new Side(db, store, applier, session);
}
private static (SyncDuplex A, SyncDuplex B) DuplexPair(int? capacity = null)
{
Channel<SyncMessage> New() => capacity is int c
? Channel.CreateBounded<SyncMessage>(c)
: Channel.CreateUnbounded<SyncMessage>();
var aToB = New();
var bToA = New();
var a = new SyncDuplex
{
Send = (m, ct) => aToB.Writer.WriteAsync(m, ct).AsTask(),
Inbox = bToA.Reader,
};
var b = new SyncDuplex
{
Send = (m, ct) => bToA.Writer.WriteAsync(m, ct).AsTask(),
Inbox = aToB.Reader,
};
return (a, b);
}
private static (SyncDuplex Duplex, ChannelWriter<SyncMessage> ToSession, ChannelReader<SyncMessage> FromSession) ScriptedPeer()
{
var toSession = Channel.CreateUnbounded<SyncMessage>();
var fromSession = Channel.CreateUnbounded<SyncMessage>();
var duplex = new SyncDuplex
{
Send = (m, ct) => fromSession.Writer.WriteAsync(m, ct).AsTask(),
Inbox = toSession.Reader,
};
return (duplex, toSession.Writer, fromSession.Reader);
}
private static Handshake MatchingHandshake(SqliteLocalDb sessionDb, string peerNodeId, uint version = 1, long lastAppliedRemoteSeq = 0)
{
var h = new Handshake { NodeId = peerNodeId, LibSchemaVersion = version, LastAppliedRemoteSeq = lastAppliedRemoteSeq };
foreach (var t in sessionDb.ReplicatedTables.Values.OrderBy(t => t.Name, StringComparer.Ordinal))
h.Tables.Add(new TableDigest { TableName = t.Name, Digest = t.Digest });
return h;
}
private static async Task<SyncMessage> NextAsync(ChannelReader<SyncMessage> reader, CancellationToken ct)
{
await reader.WaitToReadAsync(ct);
reader.TryRead(out var msg);
return msg!;
}
private static async Task<SyncMessage> NextOfCaseAsync(
ChannelReader<SyncMessage> reader, SyncMessage.MsgOneofCase msgCase, CancellationToken ct)
{
SyncMessage msg;
do { msg = await NextAsync(reader, ct); } while (msg.MsgCase != msgCase);
return msg;
}
private static async Task SwallowAsync(Task task)
{
try { await task; }
catch (OperationCanceledException) { }
}
private static async Task WaitForAsync(Func<Task<bool>> predicate, TimeSpan timeout)
{
var deadline = DateTime.UtcNow + timeout;
while (DateTime.UtcNow < deadline)
{
if (await predicate()) return;
await Task.Delay(20);
}
throw new TimeoutException("Condition not reached within " + timeout);
}
private static async Task<List<(long Id, string? Sku, long? Qty)>> ReadOrders(SqliteLocalDb db)
{
var rows = await db.QueryAsync(
"SELECT id, sku, qty FROM orders ORDER BY id",
x => (x.GetInt64(0), x.IsDBNull(1) ? null : x.GetString(1), (long?)(x.IsDBNull(2) ? null : x.GetInt64(2))));
return rows.ToList();
}
private static async Task<long> OplogCount(SqliteLocalDb db)
{
var r = await db.QueryAsync("SELECT COUNT(*) FROM __localdb_oplog", x => x.GetInt64(0));
return r[0];
}
private static async Task<long> LastAckedSeq(SqliteLocalDb db)
{
var r = await db.QueryAsync("SELECT last_acked_seq FROM __localdb_peer_state WHERE id = 1", x => x.GetInt64(0));
return r[0];
}
private static OplogEntry ProtoEntry(long seq, long id, string sku, long hlc, string nodeId = "peer") =>
new()
{
Seq = seq,
TableName = "orders",
PkJson = $"{{\"id\":{id}}}",
RowJson = $"{{\"id\":{id},\"sku\":\"{sku}\",\"qty\":1}}",
Hlc = hlc,
NodeId = nodeId,
IsTombstone = false,
};
private static long AheadHlc(TimeSpan ahead) =>
DateTimeOffset.UtcNow.Add(ahead).ToUnixTimeMilliseconds() << 16;
[Fact]
public async Task Handshake_Exchanged_BothProceed()
{
var a = await NewSideAsync();
var b = await NewSideAsync();
var (da, db) = DuplexPair();
using var cts = new CancellationTokenSource(RunTimeout);
var runA = a.Session.RunAsync(da, cts.Token);
var runB = b.Session.RunAsync(db, cts.Token);
await WaitForAsync(() => Task.FromResult(a.Session.PeerNodeId is not null && b.Session.PeerNodeId is not null), RunTimeout);
Assert.Equal(b.Db.NodeId, a.Session.PeerNodeId);
Assert.Equal(a.Db.NodeId, b.Session.PeerNodeId);
cts.Cancel();
await SwallowAsync(runA);
await SwallowAsync(runB);
}
[Fact]
public async Task Handshake_DigestMismatch_FailsClosed()
{
var a = await NewSideAsync();
var b = await NewSideAsync("CREATE TABLE orders (id INTEGER PRIMARY KEY, sku TEXT, qty INTEGER, extra TEXT)");
await a.Db.ExecuteAsync("INSERT INTO orders (id, sku, qty) VALUES (1, 'A', 5)");
var (da, db) = DuplexPair();
using var cts = new CancellationTokenSource(RunTimeout);
var runA = a.Session.RunAsync(da, cts.Token);
var runB = b.Session.RunAsync(db, cts.Token);
var exA = await Assert.ThrowsAsync<LocalDbSchemaMismatchException>(() => runA);
var exB = await Assert.ThrowsAsync<LocalDbSchemaMismatchException>(() => runB);
Assert.Contains("orders", exA.Message);
Assert.Contains("orders", exB.Message);
// No delta crossed the handshake: B never received A's row.
Assert.Empty(await ReadOrders(b.Db));
}
[Fact]
public async Task Handshake_SchemaVersionMismatch_FailsClosed()
{
var a = await NewSideAsync();
var (duplex, toSession, _) = ScriptedPeer();
using var cts = new CancellationTokenSource(RunTimeout);
var run = a.Session.RunAsync(duplex, cts.Token);
await toSession.WriteAsync(new SyncMessage { Handshake = MatchingHandshake(a.Db, "peer", version: 2) }, cts.Token);
await Assert.ThrowsAsync<LocalDbSchemaMismatchException>(() => run);
}
[Fact]
public async Task Deltas_FlowBothDirections_AcksAdvanceWatermarks()
{
var a = await NewSideAsync();
var b = await NewSideAsync();
await a.Db.ExecuteAsync("INSERT INTO orders (id, sku, qty) VALUES (1, 'FROM_A', 10)");
await b.Db.ExecuteAsync("INSERT INTO orders (id, sku, qty) VALUES (2, 'FROM_B', 20)");
var (da, db) = DuplexPair();
using var cts = new CancellationTokenSource(RunTimeout);
var runA = a.Session.RunAsync(da, cts.Token);
var runB = b.Session.RunAsync(db, cts.Token);
async Task<bool> Converged()
{
var ra = await ReadOrders(a.Db);
var rb = await ReadOrders(b.Db);
return ra.Count == 2 && rb.Count == 2
&& await OplogCount(a.Db) == 0 && await OplogCount(b.Db) == 0;
}
await WaitForAsync(Converged, RunTimeout);
var rowsA = await ReadOrders(a.Db);
var rowsB = await ReadOrders(b.Db);
Assert.Equal(rowsA, rowsB);
Assert.Equal([(1L, "FROM_A", (long?)10), (2L, "FROM_B", (long?)20)], rowsA);
Assert.True(await LastAckedSeq(a.Db) >= 1);
Assert.True(await LastAckedSeq(b.Db) >= 1);
cts.Cancel();
await SwallowAsync(runA);
await SwallowAsync(runB);
}
[Fact]
public async Task Backlog_DrainsWithoutWaitingFlushInterval()
{
var options = new ReplicationOptions { MaxBatchSize = 5, FlushInterval = TimeSpan.FromSeconds(30) };
var a = await NewSideAsync(options: options);
var b = await NewSideAsync(options: options);
const int rows = 15; // 3 x MaxBatchSize
for (var i = 1; i <= rows; i++)
await a.Db.ExecuteAsync("INSERT INTO orders (id, sku, qty) VALUES (@id, 'R', @id)", new { id = i });
var (da, db) = DuplexPair();
using var cts = new CancellationTokenSource(RunTimeout);
var runA = a.Session.RunAsync(da, cts.Token);
var runB = b.Session.RunAsync(db, cts.Token);
// FlushInterval is 30 s: reaching convergence in a couple seconds proves the pump loops
// immediately on backlog instead of waiting a flush tick between batches.
var sw = System.Diagnostics.Stopwatch.StartNew();
await WaitForAsync(async () => (await ReadOrders(b.Db)).Count == rows, TimeSpan.FromSeconds(5));
sw.Stop();
Assert.True(sw.Elapsed < TimeSpan.FromSeconds(5), $"drain took {sw.Elapsed}");
cts.Cancel();
await SwallowAsync(runA);
await SwallowAsync(runB);
}
[Fact]
public async Task Backpressure_BoundedDuplex_NoDeadlock()
{
// Capacity-1 crosswise channels with backlog in BOTH directions: under the old shared
// send-gate design each side's pump held the gate while blocked on the full channel, and
// each side's receive loop then blocked on the gate trying to send its ack — a circular
// wait. The two-lane writer breaks it: receiving enqueues acks without ever blocking.
var options = new ReplicationOptions { MaxBatchSize = 2, FlushInterval = TimeSpan.FromMilliseconds(20) };
var a = await NewSideAsync(options: options);
var b = await NewSideAsync(options: options);
const int rowsPerSide = 40;
for (var i = 1; i <= rowsPerSide; i++)
{
await a.Db.ExecuteAsync("INSERT INTO orders (id, sku, qty) VALUES (@id, 'A', @id)", new { id = i });
await b.Db.ExecuteAsync("INSERT INTO orders (id, sku, qty) VALUES (@id, 'B', @id)", new { id = 100 + i });
}
var (da, db) = DuplexPair(capacity: 1);
using var cts = new CancellationTokenSource(RunTimeout);
var runA = a.Session.RunAsync(da, cts.Token);
var runB = b.Session.RunAsync(db, cts.Token);
await WaitForAsync(
async () => (await ReadOrders(a.Db)).Count == 2 * rowsPerSide && (await ReadOrders(b.Db)).Count == 2 * rowsPerSide,
RunTimeout);
cts.Cancel();
await SwallowAsync(runA);
await SwallowAsync(runB);
}
[Fact]
public async Task OutOfOrderAck_DoesNotRegress()
{
var a = await NewSideAsync();
for (var i = 1; i <= 5; i++)
await a.Db.ExecuteAsync("INSERT INTO orders (id, sku, qty) VALUES (@id, 'R', @id)", new { id = i });
var (duplex, toSession, fromSession) = ScriptedPeer();
using var cts = new CancellationTokenSource(RunTimeout);
var run = a.Session.RunAsync(duplex, cts.Token);
await DriveHandshakeAsync(a.Db, toSession, fromSession, cts.Token);
await toSession.WriteAsync(new SyncMessage { DeltaAck = new DeltaAck { AppliedThruSeq = 5 } }, cts.Token);
await toSession.WriteAsync(new SyncMessage { DeltaAck = new DeltaAck { AppliedThruSeq = 2 } }, cts.Token);
// Barrier: the session applies inbound messages in order, so its DeltaAck for this batch
// proves both out-of-order acks above were already processed.
await toSession.WriteAsync(new SyncMessage
{
DeltaBatch = new DeltaBatch { Entries = { ProtoEntry(1, 100, "BARRIER", 5_000_000) } },
}, cts.Token);
await NextOfCaseAsync(fromSession, SyncMessage.MsgOneofCase.DeltaAck, cts.Token);
Assert.Equal(5, a.Session.PeerAckedSeq);
Assert.Equal(5, await LastAckedSeq(a.Db));
var snap = await a.Db.QueryAsync("SELECT needs_snapshot FROM __localdb_peer_state WHERE id = 1", x => x.GetInt64(0));
Assert.Equal(0, snap[0]);
cts.Cancel();
await SwallowAsync(run);
}
[Fact]
public async Task Teardown_PrimaryFaultSurfaces()
{
var a = await NewSideAsync();
// Backlog keeps the pump loop mid-work while the receive loop faults.
for (var i = 1; i <= 10; i++)
await a.Db.ExecuteAsync("INSERT INTO orders (id, sku, qty) VALUES (@id, 'R', @id)", new { id = i });
var (duplex, toSession, fromSession) = ScriptedPeer();
using var cts = new CancellationTokenSource(RunTimeout);
var run = a.Session.RunAsync(duplex, cts.Token);
await DriveHandshakeAsync(a.Db, toSession, fromSession, cts.Token);
await toSession.WriteAsync(new SyncMessage
{
DeltaBatch = new DeltaBatch
{
Entries = { new OplogEntry
{
Seq = 1, TableName = "widgets", PkJson = "{\"id\":9}",
RowJson = "{\"id\":9}", Hlc = 5_000_000, NodeId = "peer", IsTombstone = false,
} },
},
}, cts.Token);
// The receive loop's schema fault must surface — not an OperationCanceledException from
// the torn-down pump/writer siblings.
var ex = await Assert.ThrowsAsync<LocalDbSchemaMismatchException>(() => run);
Assert.Contains("widgets", ex.Message);
}
[Fact]
public async Task HlcDriftAhead_Warns()
{
var logger = new ListLogger();
var a = await NewSideAsync(
options: new ReplicationOptions { FlushInterval = TimeSpan.FromMilliseconds(20), FailClosedOnDrift = false },
logger: logger);
var (duplex, toSession, fromSession) = ScriptedPeer();
using var cts = new CancellationTokenSource(RunTimeout);
var run = a.Session.RunAsync(duplex, cts.Token);
await DriveHandshakeAsync(a.Db, toSession, fromSession, cts.Token);
// Two separate drifted batches: both apply, but only ONE warning is logged per session.
await toSession.WriteAsync(new SyncMessage
{
DeltaBatch = new DeltaBatch { Entries = { ProtoEntry(1, 1, "AHEAD1", AheadHlc(TimeSpan.FromMinutes(10))) } },
}, cts.Token);
var ack1 = await NextOfCaseAsync(fromSession, SyncMessage.MsgOneofCase.DeltaAck, cts.Token);
Assert.Equal(1, ack1.DeltaAck.AppliedThruSeq);
await toSession.WriteAsync(new SyncMessage
{
DeltaBatch = new DeltaBatch { Entries = { ProtoEntry(2, 2, "AHEAD2", AheadHlc(TimeSpan.FromMinutes(11))) } },
}, cts.Token);
var ack2 = await NextOfCaseAsync(fromSession, SyncMessage.MsgOneofCase.DeltaAck, cts.Token);
Assert.Equal(2, ack2.DeltaAck.AppliedThruSeq);
Assert.Equal(2, (await ReadOrders(a.Db)).Count); // applied despite drift
Assert.Equal(1, logger.Entries.Count(e => e.Level == LogLevel.Warning));
cts.Cancel();
await SwallowAsync(run);
}
[Fact]
public async Task HlcDriftAhead_FailClosed_DeadLetters()
{
var a = await NewSideAsync(
options: new ReplicationOptions { FlushInterval = TimeSpan.FromMilliseconds(20), FailClosedOnDrift = true });
var (duplex, toSession, fromSession) = ScriptedPeer();
using var cts = new CancellationTokenSource(RunTimeout);
var run = a.Session.RunAsync(duplex, cts.Token);
await DriveHandshakeAsync(a.Db, toSession, fromSession, cts.Token);
// One batch: seq 1 drifted (dead-lettered), seq 2 clean (applied). Watermark covers both.
await toSession.WriteAsync(new SyncMessage
{
DeltaBatch = new DeltaBatch
{
Entries =
{
ProtoEntry(1, 1, "DRIFTED", AheadHlc(TimeSpan.FromMinutes(10))),
ProtoEntry(2, 2, "CLEAN", 5_000_000),
},
},
}, cts.Token);
var ack = await NextOfCaseAsync(fromSession, SyncMessage.MsgOneofCase.DeltaAck, cts.Token);
Assert.Equal(2, ack.DeltaAck.AppliedThruSeq);
var rows = await ReadOrders(a.Db);
Assert.Single(rows);
Assert.Equal(2, rows[0].Id);
var dead = await a.Db.QueryAsync(
"SELECT pk_json, error FROM __localdb_dead_letter",
x => (Pk: x.GetString(0), Err: x.GetString(1)));
Assert.Single(dead);
Assert.Equal("{\"id\":1}", dead[0].Pk);
Assert.Contains("drift", dead[0].Err, StringComparison.OrdinalIgnoreCase);
// The session stays alive after dead-lettering: a follow-up clean batch still applies.
await toSession.WriteAsync(new SyncMessage
{
DeltaBatch = new DeltaBatch { Entries = { ProtoEntry(3, 3, "AFTER", 5_000_001) } },
}, cts.Token);
var ack3 = await NextOfCaseAsync(fromSession, SyncMessage.MsgOneofCase.DeltaAck, cts.Token);
Assert.Equal(3, ack3.DeltaAck.AppliedThruSeq);
Assert.Equal(2, (await ReadOrders(a.Db)).Count);
cts.Cancel();
await SwallowAsync(run);
}
[Fact]
public async Task PeerNeedsSnapshot_InvokesSnapshotHooks()
{
// (a) peer's HandshakeAck.snapshot_required = true -> our SnapshotSender fires, and its
// gated send delegate routes messages through the writer onto the wire.
{
var a = await NewSideAsync();
var (duplex, toSession, fromSession) = ScriptedPeer();
var sent = new TaskCompletionSource();
a.Session.SnapshotSender = (send, token) =>
{
sent.TrySetResult();
return send(new SyncMessage { SnapshotComplete = new SnapshotComplete { AsOfSeq = 7 } }, token);
};
using var cts = new CancellationTokenSource(RunTimeout);
var run = a.Session.RunAsync(duplex, cts.Token);
await NextAsync(fromSession, cts.Token); // session Handshake
await toSession.WriteAsync(new SyncMessage { Handshake = MatchingHandshake(a.Db, "peer") }, cts.Token);
await NextAsync(fromSession, cts.Token); // session HandshakeAck
await toSession.WriteAsync(new SyncMessage { HandshakeAck = new HandshakeAck { NodeId = "peer", SnapshotRequired = true } }, cts.Token);
await sent.Task.WaitAsync(RunTimeout);
var complete = await NextOfCaseAsync(fromSession, SyncMessage.MsgOneofCase.SnapshotComplete, cts.Token);
Assert.Equal(7, complete.SnapshotComplete.AsOfSeq);
cts.Cancel();
await SwallowAsync(run);
}
// (b) inbound SnapshotBegin -> our SnapshotReceiver fires with the triggering message.
{
var a = await NewSideAsync();
var (duplex, toSession, fromSession) = ScriptedPeer();
var received = new TaskCompletionSource<long>();
a.Session.SnapshotReceiver = (begin, _, _) =>
{
received.TrySetResult(begin.AsOfSeq);
return Task.CompletedTask;
};
using var cts = new CancellationTokenSource(RunTimeout);
var run = a.Session.RunAsync(duplex, cts.Token);
await DriveHandshakeAsync(a.Db, toSession, fromSession, cts.Token);
await toSession.WriteAsync(new SyncMessage { SnapshotBegin = new SnapshotBegin { AsOfSeq = 42 } }, cts.Token);
Assert.Equal(42, await received.Task.WaitAsync(RunTimeout));
cts.Cancel();
await SwallowAsync(run);
}
// (c) snapshot required but no sender hook -> NotSupportedException.
{
var a = await NewSideAsync();
var (duplex, toSession, fromSession) = ScriptedPeer();
using var cts = new CancellationTokenSource(RunTimeout);
var run = a.Session.RunAsync(duplex, cts.Token);
await NextAsync(fromSession, cts.Token);
await toSession.WriteAsync(new SyncMessage { Handshake = MatchingHandshake(a.Db, "peer") }, cts.Token);
await NextAsync(fromSession, cts.Token);
await toSession.WriteAsync(new SyncMessage { HandshakeAck = new HandshakeAck { NodeId = "peer", SnapshotRequired = true } }, cts.Token);
await Assert.ThrowsAsync<NotSupportedException>(() => run);
}
// (d) inbound SnapshotBegin but no receiver hook -> NotSupportedException.
{
var a = await NewSideAsync();
var (duplex, toSession, fromSession) = ScriptedPeer();
using var cts = new CancellationTokenSource(RunTimeout);
var run = a.Session.RunAsync(duplex, cts.Token);
await DriveHandshakeAsync(a.Db, toSession, fromSession, cts.Token);
await toSession.WriteAsync(new SyncMessage { SnapshotBegin = new SnapshotBegin { AsOfSeq = 0 } }, cts.Token);
await Assert.ThrowsAsync<NotSupportedException>(() => run);
}
}
[Fact]
public async Task SecondHandshake_MidStream_IsProtocolError()
{
var a = await NewSideAsync();
var (duplex, toSession, fromSession) = ScriptedPeer();
using var cts = new CancellationTokenSource(RunTimeout);
var run = a.Session.RunAsync(duplex, cts.Token);
await DriveHandshakeAsync(a.Db, toSession, fromSession, cts.Token);
await toSession.WriteAsync(new SyncMessage { Handshake = MatchingHandshake(a.Db, "peer") }, cts.Token);
await Assert.ThrowsAsync<InvalidOperationException>(() => run);
}
// Completes the two-phase handshake against a real session: consumes its Handshake + HandshakeAck
// and replies with a matching Handshake + a no-snapshot HandshakeAck, leaving the session in steady state.
private static async Task DriveHandshakeAsync(
SqliteLocalDb sessionDb, ChannelWriter<SyncMessage> toSession, ChannelReader<SyncMessage> fromSession, CancellationToken ct)
{
var hs = await NextAsync(fromSession, ct);
Assert.Equal(SyncMessage.MsgOneofCase.Handshake, hs.MsgCase);
await toSession.WriteAsync(new SyncMessage { Handshake = MatchingHandshake(sessionDb, "peer") }, ct);
var ack = await NextAsync(fromSession, ct);
Assert.Equal(SyncMessage.MsgOneofCase.HandshakeAck, ack.MsgCase);
await toSession.WriteAsync(new SyncMessage { HandshakeAck = new HandshakeAck { NodeId = "peer", SnapshotRequired = false } }, ct);
}
private sealed class ListLogger : ILogger
{
public List<(LogLevel Level, string Message)> Entries { get; } = [];
public IDisposable BeginScope<TState>(TState state) where TState : notnull => NullScope.Instance;
public bool IsEnabled(LogLevel logLevel) => true;
public void Log<TState>(
LogLevel logLevel, EventId eventId, TState state, Exception? exception, Func<TState, Exception?, string> formatter)
{
lock (Entries)
Entries.Add((logLevel, formatter(state, exception)));
}
private sealed class NullScope : IDisposable
{
public static readonly NullScope Instance = new();
public void Dispose() { }
}
}
}