> ## Documentation Index
> Fetch the complete documentation index at: https://ancplua.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Analyzers

> Roslyn analyzers for modern C# patterns, OpenTelemetry, AOT safety, and ecosystem conventions.

ANcpLua.Analyzers enforces code quality and prevents common bugs. Included automatically with [ANcpLua.NET.Sdk](/sdk/overview).

* **127 diagnostics** spanning design, reliability, performance, OpenTelemetry, ASP.NET Core, AOT, and version management.
* **46 automatic code fixes** for high-confidence transformations.
* **CI-friendly enforcement** through `.editorconfig` severity configuration.

## Categories

| Category          | Rules | Examples                                                              |
| ----------------- | ----: | --------------------------------------------------------------------- |
| OpenTelemetry     |    24 | Semantic conventions, ActivitySource, attribute validation, OTLP      |
| Roslyn Utilities  |    24 | Guard helpers, symbol comparison, collection extensions               |
| AOT Testing       |    10 | AotTest/TrimTest return codes, AotSafe/AotUnsafe, dynamic, reflection |
| ASP.NET Core      |     9 | Form binding, resilience, health checks, service discovery            |
| GenAI             |     9 | Required attributes, operation names, tool capability, SDK usage      |
| Reliability       |     9 | Division by zero, await using, fire-and-forget, exception handling    |
| Usage             |     9 | Span comparisons, IXmlSerializable, static lambdas, banned APIs       |
| Design            |     7 | Primary constructors, type partialness, closed hierarchies            |
| VersionManagement |     7 | Hardcoded versions, Version.props, diagnostics alignment              |
| Threading         |     6 | Lock patterns, async void, blocking calls in async                    |
| Configuration     |     5 | ServiceDefaults, endpoints, EventSource, connection strings           |
| Metrics           |     5 | Meter registration, naming, high cardinality, source generation       |
| Style             |     3 | Pattern matching, null-guard normalization                            |

## Rules

| Id                                | Category          | Description                                             | Severity | Fix |
| --------------------------------- | ----------------- | ------------------------------------------------------- | :------: | :-: |
| [AL0001](/analyzers/rules/AL0001) | Design            | Prohibit reassignment of primary constructor parameters |   Error  |  -  |
| [AL0002](/analyzers/rules/AL0002) | Design            | Don't repeat negated patterns                           |  Warning | Yes |
| [AL0003](/analyzers/rules/AL0003) | Reliability       | Don't divide by constant zero                           |   Error  |  -  |
| [AL0004](/analyzers/rules/AL0004) | Usage             | Use pattern matching for Span constants                 |  Warning | Yes |
| [AL0005](/analyzers/rules/AL0005) | Usage             | Use SequenceEqual for Span non-constants                |  Warning | Yes |
| [AL0006](/analyzers/rules/AL0006) | Design            | Field name conflicts with primary constructor           |  Warning |  -  |
| [AL0007](/analyzers/rules/AL0007) | Usage             | GetSchema should be explicitly implemented              |   Error  |  -  |
| [AL0008](/analyzers/rules/AL0008) | Usage             | GetSchema must return null                              |   Error  | Yes |
| [AL0009](/analyzers/rules/AL0009) | Usage             | Don't call IXmlSerializable.GetSchema                   |   Error  |  -  |
| [AL0010](/analyzers/rules/AL0010) | Design            | Type should be partial                                  | Disabled | Yes |
| [AL0011](/analyzers/rules/AL0011) | Threading         | Avoid lock on non-Lock types                            |  Warning | Yes |
| [AL0012](/analyzers/rules/AL0012) | OpenTelemetry     | Deprecated semantic convention                          |  Warning | Yes |
| [AL0013](/analyzers/rules/AL0013) | OpenTelemetry     | Missing telemetry schema URL                            |   Info   |  -  |
| [AL0014](/analyzers/rules/AL0014) | Style             | Prefer pattern matching for null/zero                   |  Warning | Yes |
| [AL0015](/analyzers/rules/AL0015) | Style             | Normalize null-guard style                              |   Info   | Yes |
| [AL0016](/analyzers/rules/AL0016) | Style             | Combine declaration with null-check                     |   Info   | Yes |
| [AL0017](/analyzers/rules/AL0017) | VersionManagement | Hardcoded package version                               |  Warning |  -  |
| [AL0018](/analyzers/rules/AL0018) | VersionManagement | Version.props not imported                              |  Warning |  -  |
| [AL0019](/analyzers/rules/AL0019) | VersionManagement | Undefined version variable                              |  Warning |  -  |
| [AL0020](/analyzers/rules/AL0020) | ASP.NET Core      | IFormCollection requires explicit attribute             |   Error  |  -  |
| [AL0021](/analyzers/rules/AL0021) | ASP.NET Core      | Multiple structured form sources                        |   Error  |  -  |
| [AL0022](/analyzers/rules/AL0022) | ASP.NET Core      | Mixed form collection and DTO                           |   Error  |  -  |
| [AL0023](/analyzers/rules/AL0023) | ASP.NET Core      | Unsupported form type                                   |   Error  |  -  |
| [AL0024](/analyzers/rules/AL0024) | ASP.NET Core      | Form and body conflict                                  |   Error  |  -  |
| [AL0025](/analyzers/rules/AL0025) | Usage             | Anonymous function can be static                        |  Warning | Yes |
| [AL0026](/analyzers/rules/AL0026) | Usage             | Prefer TimeProvider over legacy date/time APIs          |  Warning | Yes |
| [AL0027](/analyzers/rules/AL0027) | Usage             | Prefer System.Text.Json over Newtonsoft                 |  Warning | Yes |
| [AL0028](/analyzers/rules/AL0028) | Roslyn Utilities  | Use IsEqualTo() for symbol comparison                   |   Info   | Yes |
| [AL0029](/analyzers/rules/AL0029) | Roslyn Utilities  | Use HasAttribute() for attribute checks                 |   Info   | Yes |
| [AL0030](/analyzers/rules/AL0030) | Roslyn Utilities  | Use type hierarchy extensions                           |   Info   | Yes |
| [AL0031](/analyzers/rules/AL0031) | Roslyn Utilities  | Use operation extensions                                |   Info   | Yes |
| [AL0032](/analyzers/rules/AL0032) | Roslyn Utilities  | Use OrEmpty() extension                                 |   Info   | Yes |
| [AL0033](/analyzers/rules/AL0033) | Roslyn Utilities  | Use ToImmutableArrayOrEmpty() extension                 |   Info   | Yes |
| [AL0034](/analyzers/rules/AL0034) | Roslyn Utilities  | Use WhereNotNull() extension                            |   Info   | Yes |
| [AL0035](/analyzers/rules/AL0035) | Roslyn Utilities  | Use GetFullyQualifiedName/GetMetadataName()             |   Info   | Yes |
| [AL0036](/analyzers/rules/AL0036) | Roslyn Utilities  | Use Guard.NotNull()                                     |  Warning | Yes |
| [AL0037](/analyzers/rules/AL0037) | Roslyn Utilities  | Use TryParse extensions                                 |  Warning | Yes |
| [AL0038](/analyzers/rules/AL0038) | Roslyn Utilities  | Use GetOrNull/GetOrDefault extensions                   |  Warning | Yes |
| [AL0039](/analyzers/rules/AL0039) | Roslyn Utilities  | Use StringComparison extensions                         |  Warning | Yes |
| [AL0040](/analyzers/rules/AL0040) | Roslyn Utilities  | Use attribute argument extensions                       |  Warning | Yes |
| [AL0041](/analyzers/rules/AL0041) | AOT Testing       | \[AotTest]/\[TrimTest] must return int                  |   Error  |  -  |
| [AL0042](/analyzers/rules/AL0042) | AOT Testing       | \[AotTest]/\[TrimTest] should return 100                |  Warning |  -  |
| [AL0043](/analyzers/rules/AL0043) | AOT Testing       | \[TrimSafe] violates trim safety                        |  Warning |  -  |
| [AL0044](/analyzers/rules/AL0044) | AOT Testing       | \[AotSafe] violates AOT safety                          |  Warning |  -  |
| [AL0045](/analyzers/rules/AL0045) | Roslyn Utilities  | Use Guard.NotNullOrEmpty()                              |  Warning | Yes |
| [AL0046](/analyzers/rules/AL0046) | Roslyn Utilities  | Use Guard.NotNullOrWhiteSpace()                         |  Warning | Yes |
| [AL0047](/analyzers/rules/AL0047) | Roslyn Utilities  | Use Guard.NotZero()                                     |  Warning | Yes |
| [AL0048](/analyzers/rules/AL0048) | Roslyn Utilities  | Use Guard.NotNegative()                                 |  Warning | Yes |
| [AL0049](/analyzers/rules/AL0049) | Roslyn Utilities  | Use Guard.Positive()                                    |  Warning | Yes |
| [AL0050](/analyzers/rules/AL0050) | Roslyn Utilities  | Use Guard.NotEmptyGuid()                                |  Warning | Yes |
| [AL0051](/analyzers/rules/AL0051) | Roslyn Utilities  | Use Guard.DefinedEnum()                                 |  Warning | Yes |
| [AL0052](/analyzers/rules/AL0052) | AOT Testing       | \[AotSafe] must not call \[AotUnsafe]                   |   Error  |  -  |
| [AL0053](/analyzers/rules/AL0053) | AOT Testing       | Unnecessary \[AotUnsafe] attribute                      |  Warning |  -  |
| [AL0054](/analyzers/rules/AL0054) | VersionManagement | Diagnostic missing from documentation                   |  Warning |  -  |
| [AL0055](/analyzers/rules/AL0055) | VersionManagement | Diagnostic missing from release notes                   |  Warning |  -  |
| [AL0056](/analyzers/rules/AL0056) | VersionManagement | Diagnostic documentation mismatch                       |  Warning |  -  |
| [AL0057](/analyzers/rules/AL0057) | Threading         | Avoid async void methods                                |  Warning |  -  |
| [AL0058](/analyzers/rules/AL0058) | Threading         | Avoid lock on this                                      |  Warning |  -  |
| [AL0059](/analyzers/rules/AL0059) | Threading         | Avoid lock on typeof(T)                                 |  Warning |  -  |
| [AL0060](/analyzers/rules/AL0060) | Threading         | Avoid lock on string                                    |  Warning |  -  |
| [AL0061](/analyzers/rules/AL0061) | OpenTelemetry     | Activity missing semconv attributes                     |  Warning |  -  |
| [AL0062](/analyzers/rules/AL0062) | OpenTelemetry     | Deprecated semantic convention                          |  Warning |  -  |
| [AL0063](/analyzers/rules/AL0063) | OpenTelemetry     | Unregistered ActivitySource                             |  Warning |  -  |
| [AL0064](/analyzers/rules/AL0064) | GenAI             | GenAI span missing required attributes                  |  Warning |  -  |
| [AL0065](/analyzers/rules/AL0065) | GenAI             | Use token usage histogram                               |  Warning |  -  |
| [AL0066](/analyzers/rules/AL0066) | GenAI             | Invalid GenAI operation name                            |  Warning |  -  |
| [AL0067](/analyzers/rules/AL0067) | Metrics           | Unregistered Meter                                      |  Warning |  -  |
| [AL0068](/analyzers/rules/AL0068) | Metrics           | Invalid metric name                                     |  Warning |  -  |
| [AL0069](/analyzers/rules/AL0069) | Configuration     | Incomplete ServiceDefaults                              |  Warning |  -  |
| [AL0070](/analyzers/rules/AL0070) | Configuration     | Non-OTLP collector endpoint                             |  Warning |  -  |
| [AL0071](/analyzers/rules/AL0071) | Metrics           | Meter class must be partial static                      |   Error  | Yes |
| [AL0072](/analyzers/rules/AL0072) | Metrics           | Metric method must be partial                           |   Error  | Yes |
| [AL0073](/analyzers/rules/AL0073) | OpenTelemetry     | \[Traced] requires non-empty ActivitySourceName         |   Error  | Yes |
| [AL0074](/analyzers/rules/AL0074) | GenAI             | Deprecated GenAI attribute                              |  Warning | Yes |
| [AL0075](/analyzers/rules/AL0075) | Metrics           | High-cardinality metric tag                             |  Warning |  -  |
| [AL0076](/analyzers/rules/AL0076) | OpenTelemetry     | Missing OTel configuration                              |  Warning |  -  |
| [AL0077](/analyzers/rules/AL0077) | OpenTelemetry     | Duplicate instrumentation                               |  Warning |  -  |
| [AL0078](/analyzers/rules/AL0078) | OpenTelemetry     | Invalid ActivitySource name                             |   Error  |  -  |
| [AL0079](/analyzers/rules/AL0079) | OpenTelemetry     | Manual span recommended                                 |   Info   |  -  |
| [AL0080](/analyzers/rules/AL0080) | ASP.NET Core      | Missing resilience configuration                        |  Warning |  -  |
| [AL0081](/analyzers/rules/AL0081) | ASP.NET Core      | Missing health checks                                   |  Warning |  -  |
| [AL0082](/analyzers/rules/AL0082) | Configuration     | Consider connection string configuration                |   Info   |  -  |
| [AL0083](/analyzers/rules/AL0083) | Configuration     | Insecure endpoint                                       |  Warning |  -  |
| [AL0084](/analyzers/rules/AL0084) | ASP.NET Core      | Missing service discovery                               |  Warning |  -  |
| [AL0085](/analyzers/rules/AL0085) | OpenTelemetry     | Invalid attribute value                                 |   Error  |  -  |
| [AL0086](/analyzers/rules/AL0086) | OpenTelemetry     | Incorrect attribute type                                |  Warning |  -  |
| [AL0087](/analyzers/rules/AL0087) | OpenTelemetry     | Prefer constant attribute                               |   Info   |  -  |
| [AL0088](/analyzers/rules/AL0088) | OpenTelemetry     | Sensitive data in attribute                             |  Warning |  -  |
| [AL0089](/analyzers/rules/AL0089) | OpenTelemetry     | Missing OTLP configuration                              |  Warning |  -  |
| [AL0090](/analyzers/rules/AL0090) | OpenTelemetry     | Uncompressed OTLP export                                |  Warning |  -  |
| [AL0091](/analyzers/rules/AL0091) | OpenTelemetry     | Batch export disabled                                   |  Warning |  -  |
| [AL0092](/analyzers/rules/AL0092) | OpenTelemetry     | Consider sampling                                       |   Info   |  -  |
| [AL0093](/analyzers/rules/AL0093) | OpenTelemetry     | Missing resource attributes                             |  Warning |  -  |
| [AL0094](/analyzers/rules/AL0094) | AOT Testing       | Avoid dynamic keyword                                   |  Warning |  -  |
| [AL0095](/analyzers/rules/AL0095) | AOT Testing       | Avoid Expression.Compile()                              |  Warning |  -  |
| [AL0096](/analyzers/rules/AL0096) | Configuration     | Enable EventSource support for AOT                      |  Warning |  -  |
| [AL0101](/analyzers/rules/AL0101) | AOT Testing       | Avoid Activator.CreateInstance                          |  Warning |  -  |
| [AL0102](/analyzers/rules/AL0102) | AOT Testing       | Avoid Type.GetType                                      |  Warning |  -  |
| [AL0103](/analyzers/rules/AL0103) | Design            | Closed type hierarchy switch exhaustiveness             |  Warning | Yes |
| [AL0104](/analyzers/rules/AL0104) | Reliability       | Prefer await using for IAsyncDisposable                 |  Warning |  -  |
| [AL0105](/analyzers/rules/AL0105) | Threading         | Avoid blocking calls in async methods                   |  Warning |  -  |
| [AL0106](/analyzers/rules/AL0106) | ASP.NET Core      | Avoid Task.Run in ASP.NET Core                          |  Warning |  -  |
| [AL0107](/analyzers/rules/AL0107) | OpenTelemetry     | Orphaned \[TracedTag] attribute                         |  Warning | Yes |
| [AL0108](/analyzers/rules/AL0108) | OpenTelemetry     | Redundant \[NoTrace] attribute                          |   Info   | Yes |
| [AL0109](/analyzers/rules/AL0109) | OpenTelemetry     | Non-interceptable \[Traced] method                      |  Warning | Yes |
| [AL0110](/analyzers/rules/AL0110) | OpenTelemetry     | \[TracedTag] on out/ref parameter                       |   Error  | Yes |
| [AL0111](/analyzers/rules/AL0111) | Reliability       | SQL string interpolation in CommandText                 |  Warning |  -  |
| [AL0112](/analyzers/rules/AL0112) | Reliability       | Fire-and-forget Task                                    |  Warning |  -  |
| [AL0113](/analyzers/rules/AL0113) | OpenTelemetry     | Missing exception recording on Activity                 |  Warning |  -  |
| [AL0114](/analyzers/rules/AL0114) | Reliability       | Prefer TryParse over Parse                              |  Warning |  -  |
| [AL0115](/analyzers/rules/AL0115) | Reliability       | Empty catch block                                       |  Warning |  -  |
| [AL0116](/analyzers/rules/AL0116) | Reliability       | Exception leaked in HTTP response                       |  Warning |  -  |
| [AL0117](/analyzers/rules/AL0117) | Usage             | Unnecessary LINQ materialization                        |   Info   |  -  |
| [AL0118](/analyzers/rules/AL0118) | Reliability       | Read-modify-write without transaction                   |  Warning |  -  |
| [AL0119](/analyzers/rules/AL0119) | Roslyn Utilities  | ISymbol stored in incremental model                     |  Warning |  -  |
| [AL0120](/analyzers/rules/AL0120) | Roslyn Utilities  | Use IIncrementalGenerator over ISourceGenerator         |  Warning |  -  |
| [AL0121](/analyzers/rules/AL0121) | Roslyn Utilities  | Avoid SyntaxFactory.NormalizeWhitespace()               |  Warning | Yes |
| [AL0122](/analyzers/rules/AL0122) | Design            | DuckDB table must be partial                            |   Error  | Yes |
| [AL0123](/analyzers/rules/AL0123) | Design            | DuckDB column ordinal conflict                          |  Warning |  -  |
| [AL0124](/analyzers/rules/AL0124) | GenAI             | Non-interceptable \[AgentTraced] method                 |  Warning | Yes |
| [AL0125](/analyzers/rules/AL0125) | Roslyn Utilities  | Use StringComparison .Any extensions                    |   Info   |  -  |
| [AL0126](/analyzers/rules/AL0126) | Reliability       | CancellationToken not propagated                        |   Info   | Yes |
| [AL0127](/analyzers/rules/AL0127) | VersionManagement | Outdated MAF package version                            |  Warning |  -  |
| [AL0128](/analyzers/rules/AL0128) | GenAI             | Destructive tool must require approval                  |  Warning |  -  |
| [AL0129](/analyzers/rules/AL0129) | GenAI             | Tool must declare side effect                           |   Info   |  -  |
| [AL0130](/analyzers/rules/AL0130) | GenAI             | Tool must declare capability                            |   Info   |  -  |
| [AL0131](/analyzers/rules/AL0131) | GenAI             | Direct GenAI SDK usage bypassing IChatClient            |  Warning |  -  |

**Legend:** `Error` = build error, `Warning` = build warning, `Info` = IDE suggestion, `Disabled` = off by default.

## Refactorings

| Id                                | Description               |
| --------------------------------- | ------------------------- |
| [AR0001](/analyzers/rules/AR0001) | Snake case to Pascal case |
| [AR0002](/analyzers/rules/AR0002) | Make static lambda        |

## Configuration

Configure via `.editorconfig`. See [Configuration](/analyzers/configuration).

```ini theme={null}
[*.cs]
dotnet_diagnostic.AL0014.severity = warning
dotnet_diagnostic.AL0010.severity = none
```