fix: propagate actualListSizes via resolver context

[ysmolski]

It is needed to make router work with setting the header for actual cost via special hook that is called before writing to the client happens.

Summary by CodeRabbit

• Refactor
  • Improved how actual list sizes are tracked for cost computation: size data is now stored per-request execution context rather than response objects, and cleanup now clears this data to avoid lingering references. This streamlines internal data flow and reduces risk of stale data affecting cost calculations.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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📥 Commits

Reviewing files that changed from the base of the PR and between 0b65946 and 198f90c.

📒 Files selected for processing (2)

• execution/engine/execution_engine.go
• v2/pkg/engine/resolve/context.go

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📝 Walkthrough

Walkthrough

Actual list size tracking moved from response-level GraphQLResolveInfo to the per-request resolve Context. Resolution now populates Context.ActualListSizes, and the execution engine reads actual-cost data from execContext.resolveContext instead of the response.

Changes

Cohort / File(s)	Summary
Execution Engine execution/engine/execution_engine.go	Execute now reads ActualListSizes from execContext.resolveContext (removed use of response-held data and the internalExecutionContext.reset() call).
Resolve Context API v2/pkg/engine/resolve/context.go	Added public field ActualListSizes map[string]int to Context; Free() clears ActualListSizes.
Resolver Flow Updates v2/pkg/engine/resolve/resolve.go	Removed ActualListSizes from GraphQLResolveInfo; resolve functions assign actual list sizes to ctx.ActualListSizes instead of resp.
Module Manifest go.mod	Minor edits (lines changed +2/-8).

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

🚥 Pre-merge checks | ✅ 2

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'fix: propagate actualListSizes via resolver context' accurately and concisely summarizes the main change—moving the ActualListSizes field from the response to the resolver context for cost header propagation.

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✨ Finishing Touches

• 📝 Generate docstrings (stacked PR)
• 📝 Generate docstrings (commit on current branch)

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch yury/eng-8986-expose-costs-in-response-headers

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[coderabbitai]

Actionable comments posted: 1

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Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@v2/pkg/engine/resolve/context.go`:
- Around line 48-51: Context.Free currently doesn't clear the per-request map
ActualListSizes, so add ActualListSizes to the cleanup logic inside the
Context.Free method: ensure Context.Free resets or nils out c.ActualListSizes
(in the same place other per-request fields are cleared) to avoid retaining
stale data or memory when contexts are reused; locate the Context.Free function
and update it to clear c.ActualListSizes alongside the other cleanup steps.

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ℹ️ Review info

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between d2657bf and 0b65946.

📒 Files selected for processing (3)

• execution/engine/execution_engine.go
• v2/pkg/engine/resolve/context.go
• v2/pkg/engine/resolve/resolve.go