PollyAnalyzers

Free, MIT-licensed Roslyn analyzers for async/resilience anti-patterns. No per-seat license required — ever.

Why PollyAnalyzers?

ReSharper (~$249+/seat/year) and similar commercial tools are broad style/inspection suites. Free tools like Roslynator and SonarLint already cover general C# code smells well. What none of them specifically targets is reliability: the handful of async/exception-handling mistakes that cause deadlocks, silent failures, and un-cancellable requests in production. PollyAnalyzers is a small, focused analyzer pack for exactly that gap, built by the same team that maintains 28+ Polly v8 resilience integration packages.

var data = httpClient.GetAsync(url).Result;              // PLY001: blocking call, deadlock risk
async void OnTimerElapsed(object? state) { ... }          // PLY002: async void, unobservable exceptions
SendWelcomeEmailAsync(order);                             // PLY003: fire-and-forget, exception lost
catch (Exception) { }                                     // PLY004: swallowed exception
await httpClient.GetAsync(url);                           // PLY005: cancellationToken in scope, not passed

Install

dotnet add package Swevo.PollyAnalyzers

Works automatically in Visual Studio, Rider, and VS Code (via the C# Dev Kit/OmniSharp Roslyn workspace) the moment the package is referenced — no separate IDE extension to install.

Rules

ID	Severity	Title
PLY001	Warning	Blocking call on async API (.Result, .Wait(), .GetAwaiter().GetResult()) may cause a deadlock
PLY002	Warning	Avoid async void methods (except conventional event handlers)
PLY003	Warning	Fire-and-forget task is not awaited, assigned, or discarded
PLY004	Warning	Empty catch block swallows exceptions
PLY005	Info	Async call drops an available CancellationToken

Each rule ships with one or more code fixes (Ctrl+. / Alt+Enter):

• PLY001 — replace with await (offered only inside an already-async method, since the fix can't safely make a sync method async and update every caller for you).
• PLY002 — change the return type to Task.
• PLY003 — discard with _ = (always safe), or await the call (offered inside async methods).
• PLY004 — insert throw; to rethrow instead of swallowing.
• PLY005 — append the in-scope CancellationToken as the call's last argument.

Suppressing a rule

Standard Roslyn suppression applies — per line:

#pragma warning disable PLY001
var data = httpClient.GetAsync(url).Result;
#pragma warning restore PLY001

or per-project via .editorconfig:

dotnet_diagnostic.PLY001.severity = none

Design goals

• MIT licensed, forever. No commercial tier, no per-seat fees.
• Narrow and precise. Five rules that catch real production incidents, not hundreds of style opinions — pairs cleanly alongside Roslynator/SonarLint rather than competing with them.
• Actionable. Every rule ships with a code fix, not just a warning.

Roadmap

• Additional rules are being considered based on real-world false-positive/false-negative feedback: HttpClient calls with no timeout or retry policy configured, and ConfigureAwait(false) guidance for library code.

Related Packages

Package	Downloads	Description
PollyHealthChecks		ASP.NET Core health checks for Polly v8 circuit breakers — expose circuit-breaker state (Closed, HalfOpen, Open, Isolated) as /health endpoint responses
PollyOpenTelemetry		OpenTelemetry instrumentation for Polly v8 resilience pipelines
PollyBackoff		Backoff delay strategies for Polly v8 resilience pipelines
PollyEFCore		Polly v8 resilience pipelines for Entity Framework Core — wrap every EF Core query and SaveChanges with retry, timeout and circuit-breaker via a single AddPollyResilience() call
PollyRabbitMQ		Polly v8 resilience for RabbitMQ.Client v7+ — retry, circuit-breaker, and timeout for IChannel operations, with built-in RabbitMqTransientErrors predicate covering AlreadyClosedException, BrokerUnreachableException, OperationInterruptedException, and ConnectFailureException
PollyMongo		Polly v8 resilience pipelines for MongoDB.Driver — wrap Find, InsertOne, UpdateOne, DeleteOne and other IMongoCollection calls with retry, timeout, circuit-breaker, and more using a single ResilientMongoCollection decorator
PollyDapper		Polly v8 resilience pipelines for Dapper — wrap QueryAsync, ExecuteAsync, and other Dapper calls with retry, timeout, circuit-breaker, and more using a single ResilientDbConnection decorator
PollyMediatR		Polly v8 resilience pipelines for MediatR — add retry, timeout, circuit-breaker, rate-limiting, hedging, and chaos engineering to any MediatR request handler with a single line of DI registration
PollySqlClient		Polly v8 resilience pipelines for Microsoft.Data.SqlClient (SQL Server and Azure SQL) — retry, timeout, and circuit-breaker for SqlConnection queries and commands, plus a built-in SqlServerTransientErrors predicate covering all common SQL Server and Azure SQL transient error numbers
PollyRedis		Polly v8 resilience for StackExchange.Redis

💼 Need .NET consulting?

I'm the author of PollyAnalyzers and a suite of compile-time source generators (AutoWire, AutoMap.Generator) and 28+ Polly v8 resilience packages. I'm available for consulting on Polly v8 resilience, Azure cloud architecture, and clean .NET design.

→ solidqualitysolutions.com · LinkedIn

Also by the same author

🌐 Full suite overview: swevo.github.io

Package	Description
FluentPdf	Free, MIT-licensed fluent PDF generation — alternative to QuestPDF's commercial license.
AutoBus	Free, MIT-licensed message bus — alternative to MassTransit's commercial license.
AutoArchitecture	Free, MIT-licensed compile-time architecture rule enforcement — alternative to NDepend.
AutoAssert	Free, MIT-licensed fluent assertions — alternative to FluentAssertions' commercial license.
AutoWire	Compile-time DI auto-registration — [Scoped]/[Singleton]/[Transient] generates IServiceCollection registration code.
PollyAction	Free retry/backoff GitHub Action — wrap any CI step with exponential-backoff retries.

License

MIT © Justin Bannister