fix(rivetkit): infer T from step/tryStep config object in workflow context wrapper

[abcxff]

Description

Please include a summary of the changes and the related issue. Please also include relevant motivation and context.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[abcxff]

• fix(rivetkit): infer T from step/tryStep config object in workflow context wrapper #5124 👈 (View in Graphite)
• chore(wasm-pack): upgrade wasm-pack to now-functioning v0.15.0 #5125
• feat(workflow-engine): add retryOnTimeout opt-in for step timeout retries #5089 : 1 other dependent PR (#5065 )
• fix(rivetkit): wire CancellationToken through waitForNamesAvailable to eliminate KV busy-polling #5063 : 1 other dependent PR (#5050 )
• fix(rivetkit): fix BigInt serialization in inspector workflow history and state deserialization #5058
• main

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[railway-app]

🚅 Deployed to the rivet-pr-5124 environment in rivet-frontend

Service	Status	Web	Updated (UTC)
kitchen-sink	❌ Build Failed (View Logs)	Web	Jun 3, 2026 at 1:12 am
frontend-cloud	❌ Build Failed (View Logs)	Web	Jun 2, 2026 at 8:18 pm
frontend-inspector	❌ Build Failed (View Logs)	Web	Jun 2, 2026 at 8:17 pm
mcp-hub	✅ Success (View Logs)	Web	Jun 2, 2026 at 8:11 pm
website	❌ Build Failed (View Logs)	Web	Jun 2, 2026 at 8:10 pm
ladle	❌ Build Failed (View Logs)	Web	Jun 2, 2026 at 8:10 pm

[claude]

Code Review

Summary: This PR fixes a TypeScript generic inference bug in ActorWorkflowContext.step and ActorWorkflowContext.tryStep by replacing Parameters<WorkflowContextInterface["step"]>[0] with the direct generic type StepConfig<T>.

The Bug Being Fixed

TypeScript's Parameters<> utility applied to an overloaded function always picks the last overload, and cannot propagate the generic T. The original code produced effectively StepConfig<unknown>, so callers got Promise<unknown> return types when passing a config object. Using StepConfig<T> directly ties the config's run: () => Promise<T> to the method's own T, restoring proper inference.

Observations

Minor: The file has // @ts-nocheck at the top — pre-existing, not introduced here. The corrected signatures still matter for consumers since TypeScript performs inference at call sites even when the implementation file has @ts-nocheck.

Consistency gap: The try method on the same class still uses Parameters<WorkflowContextInterface["try"]>[0]. It may have the same inference problem and could be fixed in a follow-up.

Assessment

Minimal, focused, correct change. No new behavior introduced — pure type-level fix.

[abcxff]

Merge activity

• Jun 3, 1:04 AM UTC: A user started a stack merge that includes this pull request via Graphite.
• Jun 3, 1:12 AM UTC: Graphite rebased this pull request as part of a merge.
• Jun 3, 1:13 AM UTC: @abcxff merged this pull request with Graphite.