Add MaxBatchSize support on source-generated DataLoader

[michaelstaib]

Implements #9897

[Copilot]

Pull request overview

This PR implements issue #9897 by adding MaxBatchSize support to source-generated DataLoaders, flowing the value from [DataLoader(MaxBatchSize = ...)] through the analyzer model into generated DataLoader constructors (via DataLoaderOptions).

Changes:

• Add MaxBatchSize to DataLoaderAttribute and extract it in the analyzer (DataLoaderInfo / DataLoaderAttributeHelper).
• Update the source generator to emit an options wrapper (CreateOptions) that applies MaxBatchSize when specified.
• Add analyzer snapshot tests and an integration test verifying runtime batching splits keys according to MaxBatchSize.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/HotChocolate/Core/test/Types.Analyzers.Tests/DataLoaderTests.cs	Adds snapshot-based analyzer tests for MaxBatchSize codegen.
src/HotChocolate/Core/test/Types.Analyzers.Tests/snapshots/DataLoaderTests.GenerateSource_BatchDataLoader_With_MaxBatchSize_MatchesSnapshot.md	Snapshot verifying generated batch DataLoader applies MaxBatchSize via options.
src/HotChocolate/Core/test/Types.Analyzers.Tests/snapshots/DataLoaderTests.GenerateSource_CacheDataLoader_With_MaxBatchSize_MatchesSnapshot.md	Snapshot verifying generated cache DataLoader applies MaxBatchSize via options.
src/HotChocolate/Core/test/Types.Analyzers.Integration.Tests/DataLoaderTests.cs	Integration test asserting dispatched batch sizes match MaxBatchSize splitting behavior.
src/HotChocolate/Core/src/Types.Analyzers/Models/DataLoaderInfo.cs	Adds MaxBatchSize to the analyzer model.
src/HotChocolate/Core/src/Types.Analyzers/Helpers/DataLoaderAttributeHelper.cs	Extracts MaxBatchSize from attribute named arguments.
src/HotChocolate/Core/src/Types.Analyzers/Generators/DataLoaderGenerator.cs	Passes MaxBatchSize into the file builder when generating constructors.
src/HotChocolate/Core/src/Types.Analyzers/FileBuilders/DataLoaderFileBuilder.cs	Generates CreateOptions(options) and sets local.MaxBatchSize when specified.
src/GreenDonut/src/GreenDonut.Abstractions/Attributes/DataLoaderAttribute.cs	Adds MaxBatchSize to the public attribute API (docs + property).

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[github-actions]

Patch coverage

97.0% of changed lines covered (32/33)

File	Covered	Changed	Patch %
…/GreenDonut.Abstractions/Attributes/DataLoaderAttribute.cs	0	1	0.0% 🔴
…/src/Types.Analyzers/FileBuilders/DataLoaderFileBuilder.cs	20	20	100.0% 🟢
…/Core/src/Types.Analyzers/Generators/DataLoaderGenerator.cs	2	2	100.0% 🟢
…/src/Types.Analyzers/Helpers/DataLoaderAttributeHelper.cs	8	8	100.0% 🟢
…/Core/src/Types.Analyzers/Models/DataLoaderInfo.cs	2	2	100.0% 🟢

Uncovered changed lines (JSON)

{
  "sha": "931fe6402feb0fea7308299e7401dcbcd67fa82e",
  "files": [
    { "path": "src/GreenDonut/src/GreenDonut.Abstractions/Attributes/DataLoaderAttribute.cs", "ranges": [[36, 36]] }
  ]
}

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Project coverage: 52.5% (217057/413246 lines)