Compiler Diagnostics

CaeriusNet's Roslyn source generators emit compile-time diagnostics to catch configuration and mapping errors before runtime. Each diagnostic has a unique ID, severity, and actionable guidance.

Diagnostic reference

ID	Severity	Title	Description
CAERIUS001	Error	Type must be sealed	A [GenerateDto] or [GenerateTvp] type is missing the sealed modifier
CAERIUS002	Error	Type must be partial	A [GenerateDto] or [GenerateTvp] type is missing the partial modifier
CAERIUS003	Error	Primary constructor required	The type does not use a primary constructor for its parameters
CAERIUS004	Error	Empty primary constructor	The primary constructor has no parameters (no columns to map)
CAERIUS005	Warning	Unmapped CLR type falls back to sql_variant	A property type has no native SQL Server mapping
CAERIUS006	Warning	Unsupported type for SQL Server mapping	A property type uses sql_variant fallback with performance implications

Severity levels

Severity	Build impact	Action required
Error	Fails compilation	Must fix before building
Warning	Compilation succeeds	Review and fix or suppress intentionally

How to suppress diagnostics

Per-declaration with #pragma

#pragma warning disable CAERIUS005
[GenerateDto]
public sealed partial record FlexibleDto(int Id, object DynamicValue);
#pragma warning restore CAERIUS005

Project-wide with .editorconfig

[*.cs]
# Suppress specific diagnostic
dotnet_diagnostic.CAERIUS005.severity = none

# Downgrade to suggestion
dotnet_diagnostic.CAERIUS006.severity = suggestion

Via <NoWarn> in .csproj

<PropertyGroup>
    <NoWarn>$(NoWarn);CAERIUS005;CAERIUS006</NoWarn>
</PropertyGroup>

How to escalate severity

Promote warnings to errors to enforce stricter rules in CI:

Via .editorconfig

[*.cs]
# Treat sql_variant fallback as a build error
dotnet_diagnostic.CAERIUS005.severity = error
dotnet_diagnostic.CAERIUS006.severity = error

Via <WarningsAsErrors> in .csproj

<PropertyGroup>
    <WarningsAsErrors>$(WarningsAsErrors);CAERIUS005;CAERIUS006</WarningsAsErrors>
</PropertyGroup>

CI enforcement

Escalating CAERIUS005 and CAERIUS006 to errors in your CI .editorconfig prevents accidental sql_variant usage from reaching production.

Troubleshooting

Symptom	Cause	Fix
No diagnostics emitted	Generator not running	Ensure CaeriusNet package is referenced and IDE recognizes analyzers
Diagnostics not appearing in IDE	IDE cache stale	Restart IDE or run dotnet build from CLI
Suppression not working	Wrong scope	Ensure #pragma wraps the type declaration, not just the file

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See also: Source Generators — full guide to [GenerateDto] and [GenerateTvp] code generation.