116 lines
3.9 KiB
C#
116 lines
3.9 KiB
C#
using Microsoft.Extensions.Logging.Abstractions;
|
|
|
|
namespace ScadaLink.Host.Tests;
|
|
|
|
/// <summary>
|
|
/// Host-010: startup preconditions (database migration) must tolerate a database
|
|
/// that is briefly unavailable at boot — common when an app container and its DB
|
|
/// container start together — via a bounded retry with backoff.
|
|
/// </summary>
|
|
public class StartupRetryTests
|
|
{
|
|
[Fact]
|
|
public async Task ExecuteWithRetry_SucceedsFirstTry_RunsOnce()
|
|
{
|
|
var attempts = 0;
|
|
await StartupRetry.ExecuteWithRetryAsync(
|
|
"test-op",
|
|
() => { attempts++; return Task.CompletedTask; },
|
|
maxAttempts: 5,
|
|
initialDelay: TimeSpan.FromMilliseconds(1),
|
|
NullLogger.Instance);
|
|
|
|
Assert.Equal(1, attempts);
|
|
}
|
|
|
|
[Fact]
|
|
public async Task ExecuteWithRetry_TransientFailures_RetriesUntilSuccess()
|
|
{
|
|
var attempts = 0;
|
|
await StartupRetry.ExecuteWithRetryAsync(
|
|
"test-op",
|
|
() =>
|
|
{
|
|
attempts++;
|
|
if (attempts < 3)
|
|
throw new InvalidOperationException("db not ready");
|
|
return Task.CompletedTask;
|
|
},
|
|
maxAttempts: 5,
|
|
initialDelay: TimeSpan.FromMilliseconds(1),
|
|
NullLogger.Instance);
|
|
|
|
Assert.Equal(3, attempts);
|
|
}
|
|
|
|
[Fact]
|
|
public async Task ExecuteWithRetry_ExhaustsAttempts_RethrowsLastException()
|
|
{
|
|
var attempts = 0;
|
|
var ex = await Assert.ThrowsAsync<InvalidOperationException>(() =>
|
|
StartupRetry.ExecuteWithRetryAsync(
|
|
"test-op",
|
|
() =>
|
|
{
|
|
attempts++;
|
|
throw new InvalidOperationException($"failure {attempts}");
|
|
},
|
|
maxAttempts: 3,
|
|
initialDelay: TimeSpan.FromMilliseconds(1),
|
|
NullLogger.Instance,
|
|
isTransient: _ => true));
|
|
|
|
Assert.Equal(3, attempts);
|
|
Assert.Equal("failure 3", ex.Message);
|
|
}
|
|
|
|
[Fact]
|
|
public async Task ExecuteWithRetry_NonTransientFailure_RethrowsAfterSingleAttempt()
|
|
{
|
|
// Host-015: a permanent failure (e.g. a schema-version mismatch) must NOT be
|
|
// retried — retrying it cannot succeed and only delays the fatal exit by
|
|
// minutes. The isTransient predicate classifies it as non-retryable, so the
|
|
// operation runs exactly once before the exception propagates.
|
|
var attempts = 0;
|
|
var ex = await Assert.ThrowsAsync<InvalidOperationException>(() =>
|
|
StartupRetry.ExecuteWithRetryAsync(
|
|
"test-op",
|
|
() =>
|
|
{
|
|
attempts++;
|
|
throw new InvalidOperationException("permanent schema mismatch");
|
|
},
|
|
maxAttempts: 8,
|
|
initialDelay: TimeSpan.FromMilliseconds(1),
|
|
NullLogger.Instance,
|
|
isTransient: _ => false));
|
|
|
|
Assert.Equal(1, attempts);
|
|
Assert.Equal("permanent schema mismatch", ex.Message);
|
|
}
|
|
|
|
[Fact]
|
|
public async Task ExecuteWithRetry_TransientThenPermanent_StopsAtPermanent()
|
|
{
|
|
// A transient fault is retried; a subsequent permanent fault is not.
|
|
var attempts = 0;
|
|
await Assert.ThrowsAsync<InvalidOperationException>(() =>
|
|
StartupRetry.ExecuteWithRetryAsync(
|
|
"test-op",
|
|
() =>
|
|
{
|
|
attempts++;
|
|
if (attempts == 1)
|
|
throw new TimeoutException("transient");
|
|
throw new InvalidOperationException("permanent");
|
|
},
|
|
maxAttempts: 8,
|
|
initialDelay: TimeSpan.FromMilliseconds(1),
|
|
NullLogger.Instance,
|
|
isTransient: e => e is TimeoutException));
|
|
|
|
// 1 transient (retried) + 1 permanent (not retried) = 2.
|
|
Assert.Equal(2, attempts);
|
|
}
|
|
}
|