Generate collection-shape drill-in overloads (#6185) by thomhurst · Pull Request #6218 · thomhurst/TUnit (original) (raw)

Adds CollectionShapeFanOutGenerator, a Roslyn incremental generator that replaces hand-written "one method per collection shape" boilerplate at three sites, driven by a single shape->source registry plus symbol reflection.

• Emitter A: [GenerateCollectionShapeDrillIns] on a drill-in source emits the full shape-specific assertion surface (Count/Contains/HasItemAt/IsSubsetOf/ ContainsKey/...) onto DictionaryValueSource. Fixes the CS0411 where .Value.Count() bound to LINQ Enumerable.Count when a dictionary value is itself a collection. Signatures are reflected from each shape's assertion source, so per-shape differences (e.g. the comparer param on ReadOnlyList.HasItemAt that IList lacks) are always correct.
• Emitter B: replaces CollectionItemSatisfiesExtensions.cs.
• Emitter C: replaces the #5707 Count(itemAssertion) block in AssertionExtensions.

Concrete value shapes (List/Dictionary<K,V>) upcast their context via a generated helper that preserves PendingPreWork, so the ContainsKey pre-work still runs before the value is read.

Sites B and C reproduce their existing public API exactly (PublicAPI net-zero); Emitter A is a deliberate full-surface expansion.

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…nerator

Renames the codegen vocabulary to match the repo's "source"/"assertion" terms instead of the ad-hoc "DrillIn"/"FanOut"/"ItemSource" coinages:

• CollectionShapeFanOutGenerator -> CollectionShapeAssertionGenerator
• [GenerateCollectionShapeDrillIns] -> [GenerateCollectionShapeAssertions]
• [GenerateCollectionShapeItemSourceOverloads] -> [GenerateCollectionShapeSatisfiesOverloads]
• generated {Wrapper}CollectionShapeDrillInExtensions -> {Wrapper}CollectionShapeAssertions
• internal model/method names (DrillInModel/BuildDrillInModel/EmitDrillIn -> WrapperModel/BuildWrapperModel/EmitWrapperAssertions)

Pure rename: generated output and behaviour are unchanged. PublicAPI snapshots are a symmetric rename (5 names in/out, no other surface change).

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…-set docs

• Collect() the Satisfies/Count trigger pipelines so each single output file is emitted exactly once even if a second method ever carries the trigger attribute (avoids a CS8785 duplicate-hint-name build failure).
• Group ExcludedNames with per-group rationale (IAssertionSource members / Assertion infrastructure / System.Object) so a future maintainer knows where a new entry belongs.

Generator-internal only; generated output and public API are unchanged.

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The three GenerateCollectionShape* trigger attributes are internal generator plumbing, not a public extensibility point, so mark them internal — removing them from the public API surface.

They are applied only within TUnit.Assertions itself. The generator matches triggers by metadata name, so the generator snapshot test's TestData declares a same-named local stand-in attribute rather than depending on the internal one (strong naming makes InternalsVisibleTo to the unsigned test project impractical — the same wall TUnit.Mocks hit).

PublicAPI snapshots updated: removal of the three attribute types only.

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…nerator

Addresses static-analysis nits on the new generator (matches the repo's always-brace convention; no brace-less single-line ifs elsewhere in the generators):

• Add braces to all single-line if statements.
• Derive shape arity from the metadata-name digit instead of int.Parse (no FormatException path, no culture dependency).

Generator-internal only; generated output is unchanged.

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…work helper

Design cleanup for the collection-shape codegen (no public API or behaviour change; PublicAPI snapshots unchanged):

• Split the single multi-purpose generator into two single-purpose ones sharing a named registry:

  • CollectionShapeRegistry — the one shape -> source -> seed table + emit helpers (single source of truth; documents the per-SeedKind ctor/FromContext contract).
  • CollectionShapeAssertionGenerator — reflection-driven full wrapper surface (Emitter A).
  • CollectionShapeOverloadGenerator — the fixed per-shape Satisfies/Count templates (B/C).

• Move the pre-work-preserving identity upcast out of the generated output into a real internal AssertionContext.MapPreservingPreWork helper. Generated concrete-shape seeds now call it instead of each file emitting a ~15-line Upcast helper, so the output is smaller and the logic is real, testable source. This also removes the need to conditionally emit that helper.

Generator-A snapshots updated (helper removed, shorter seeds); behaviour verified by the existing value/#5707/Satisfies tests.

This was referenced

Jun 15, 2026

github-actions Bot pushed a commit to IntelliTect/CodingGuidelines that referenced this pull request

Jun 15, 2026

Updated TUnit.Core from 1.51.0 to 1.55.2.

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This was referenced

Jun 15, 2026

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