Compiler diagnostics

CaeriusNet's Roslyn analyzer emits compile-time diagnostics for [GenerateDto], [GenerateTvp], and AutoContracts manifest issues. The analyzer ships inside the CaeriusNet NuGet package; no extra reference is required.

Use this page to decide whether a diagnostic must be fixed, can be suppressed, or should be escalated in CI.

Diagnostic reference

ID	Severity	Title	Triggered when
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 declare a primary constructor (or the constructor has no parameters)
CAERIUS004	Error	[GenerateTvp] requires a non-empty TvpName	The attribute sets TvpName to an empty or whitespace-only string
CAERIUS005	Warning	Unmapped CLR type falls back to sql_variant	A constructor parameter has a type with no native SQL Server mapping
CAERIUS006	Error	Generator target shape is not supported	A generator target cannot be represented safely
CAERIUS200	Error	AutoContracts manifest is missing	AutoContracts is enabled, but caerius.contracts.json has not been generated or restored
CAERIUS201	Error	Stored procedure could not be found	The manifest references a procedure that is missing from the inspected SQL Server database
CAERIUS202	Error	Referenced TVP type is missing	A procedure parameter references a TVP type that is missing from SQL Server metadata
CAERIUS203	Error	TVP SQL type is not supported	A referenced TVP column uses a SQL Server type AutoContracts cannot generate safely
CAERIUS204	Error	First projection cannot be determined	SQL Server cannot expose a stable first result set for the procedure
CAERIUS205	Warning	Stored procedure has no result set	The procedure is included for read-contract generation but SQL Server reports no result set
CAERIUS206	Error	OUTPUT parameters are not supported	A procedure declares one or more OUTPUT parameters
CAERIUS207	Error	SQL type cannot be mapped	A procedure parameter or projected column uses an unmappable SQL Server type
CAERIUS208	Policy-dependent	Nullable column violates policy	SQL Server metadata marks a projected column nullable and the active policy rejects it
CAERIUS209	Error	Contract hash differs during Verify	Verify found drift between SQL Server metadata and caerius.contracts.json
CAERIUS210	Warning	Stored procedure is probably incompatible	Metadata discovery found an incompatible shape without enough detail for a narrower diagnostic

Severity levels

Severity	Build impact	Action required
Error	Fails compilation	Must be fixed before the project builds
Warning	Compilation succeeds	Review and fix, or suppress intentionally

Full rule pages

For examples and rule-specific guidance, open the individual pages under Diagnostic rules.

Suppressing 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 entirely
dotnet_diagnostic.CAERIUS005.severity = none

# Or downgrade to a suggestion
# dotnet_diagnostic.CAERIUS005.severity = suggestion

Via <NoWarn> in .csproj

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

Escalating 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

Via <WarningsAsErrors> in .csproj

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

CI enforcement

Escalating CAERIUS005 and AutoContracts warnings such as CAERIUS205, CAERIUS208, or CAERIUS210 in your CI .editorconfig prevents accidental contract drift or ambiguous metadata from reaching production.

Troubleshooting

Symptom	Cause	Fix
No diagnostics emitted	Analyzer not loaded	Ensure the CaeriusNet package is referenced (the analyzer ships in the same package)
Diagnostics not visible in IDE	IDE cache stale	Restart the IDE or run dotnet build from the CLI
#pragma suppression has no effect	Wrong scope	Wrap the type declaration, not the file or a member

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See also: source generators - the full guide to [GenerateDto] and [GenerateTvp].