Report QueryComplexity variable coercion errors instead of throwing

[ruudk]

DocumentValidator::validate() is documented to return validation errors, and every other rule reports them through the validation context. But QueryComplexity coerces variable values (it needs them to evaluate @include/@Skip and to build arguments for complexityFn) and threw a raw Error when coercion failed. Callers using DocumentValidator directly rather than GraphQL::promiseToExecute() — which sets the variables and wraps everything in try/catch — got an uncaught exception for something that is a plain input problem.

Coercion errors now go to $context->reportError() and complexity analysis is abandoned for the rest of the document: without usable variable values the computed complexity is meaningless, so reporting a max-complexity error on top of it would be misleading, and calling a user-supplied complexityFn with empty arguments could throw. For the same reason getQueryComplexity() is reset to 0, so it cannot hand back the partial sum accumulated before coercion failed.

This also improves the errors themselves. The old code concatenated the messages of all coercion errors into one Error, discarding the source locations; each error is now reported individually with the location of its variable definition, matching what the executor produces for the same bad input.

While here, buildFieldArguments() reuses the per-document coercion cache instead of coercing all variables again for every field that has a complexityFn.

Fixes #1967

[Copilot]

Pull request overview

This PR updates the QueryComplexity validation rule so variable coercion failures are reported as regular validation errors (via the validation context) instead of throwing, bringing it in line with how DocumentValidator::validate() is documented to behave.

Changes:

• Report variable coercion errors through $context->reportError() and abandon complexity analysis for that document.
• Reuse the per-document coerced variable cache when building field arguments (avoids re-coercing per field with a complexityFn).
• Add regression tests covering coercion failures (including multiple errors, error locations, and per-document reset), plus a changelog entry.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
src/Validator/Rules/QueryComplexity.php	Converts coercion failures from thrown exceptions into reported validation errors and stops complexity enforcement when coercion fails.
tests/Validator/QueryComplexityTest.php	Adds coverage for coercion-failure behavior (messages, locations, multiple errors, caching/reset semantics).
CHANGELOG.md	Documents the fix under Unreleased.

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[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.