JasperFx.Events.ComplianceTests

JasperFx.Events.ComplianceTests

Shared behavioral compliance test suites for Critter Stack event stores — the same event sourcing expectations asserted against Marten (PostgreSQL), Polecat (SQL Server), and any future store built on JasperFx.Events.

This package ships C# source, not a compiled assembly. That is forced, not a preference: JasperFx.Events.SourceGenerator emits aggregate dispatchers per consuming assembly and binds each product's own session type, so the shared aggregates have to be compiled inside each consumer. Compiling in the consumer also sidesteps package-version skew and LangVersion/ImplicitUsings differences between the repos.

Using it

Reference the package from a test project that already has xunit v3 and Shouldly, then supply two things.

1. Four global aliases naming your store's own types. The shared suites declare aggregates and projections at file scope, so they cannot reach the <TOperations, TQuerySession> pair the suite classes are generic over. The source generator resolves these by type name, so aliases are enough:

global using ComplianceQuerySession = Marten.IQuerySession;
global using ComplianceOperations = Marten.IDocumentOperations;
global using ComplianceEventProjection = Marten.Events.Projections.EventProjection;
global using ComplianceStringPartyProjectionBase =
    Marten.Events.Aggregation.SingleStreamProjection<
        JasperFx.Events.ComplianceTests.StringQuestParty, string>;

ComplianceQuerySession binds the EvolveAsync(IEvent, …) convention on the self-aggregating fixtures; the next two bind the EventProjection suites to your product's own projection base and writable session. The last one is a closed generic, because the single stream projection base is generic over both the document and its identity — it binds the string-identity suite's custom projection to your product's SingleStreamProjection<TDoc, TId>.

2. A concrete fixture closing EventStoreComplianceFixture<TOperations, TQuerySession> over your store's session pair. Everything portable in the suites runs through the shared JasperFx surfaces (IEventStoreOperations, IEventRegistry, IProjectionDaemon); the fixture only has to supply what no shared interface declares — store construction from a ComplianceStoreConfig, session acquisition, SaveChangesAsync, document load-back, batched DCB queries, and teardown.

Then enroll each suite with an empty subclass:

public class dcb_tag_query_and_consistency_compliance
    : DcbTagQueryAndConsistencyCompliance<MyComplianceFixture, IDocumentOperations, IQuerySession>;

Capability gates

Where a store genuinely cannot support a behavior, override the virtual bool Supports... flags on the fixture; the affected tests skip rather than fail. Gates are meant to be temporary and tracked — a suite failing on your store is usually a product bug, not a test to soften.

Local dev loop

Both current consumers accept a ComplianceSourceDir property that swaps the published suites for a working copy, so a new wave can be validated against a real store before the JasperFx release:

dotnet test src/EventSourcingTests/EventSourcingTests.csproj -f net9.0 \
    -p:ComplianceSourceDir=/path/to/jasperfx/src/JasperFx.Events.ComplianceTests

What is in scope

The library asserts behavior that every JasperFx.Events store owes its users, reached through the shared interfaces (IEventStoreOperations, IQueryEventStore, IEventRegistry, IEventStore, IProjectionDaemon). Covered today:

What is deliberately out of scope

Storage layout and DDL, table partitioning, node distribution / HotCold, high-water detection internals, and anything on the document-db side (LINQ, patching, session semantics) — the last because no shared document store contract exists yet. If a behavior only makes sense in terms of one engine's storage, it belongs in that product's own test suite, not here.

New cross-store event sourcing behavior should land as a compliance suite first, and only then be enrolled by each product.