refactor: change step handler input to use asymmetric pattern for better type safety

[jumski]

Asymmetric Step Input Pattern for Improved Type Safety and Composition

This PR introduces a significant improvement to the step input pattern across the PgFlow DSL:

• Root steps now receive flow input directly (no run wrapper)
• Dependent steps receive only their dependencies (flow input available via context.flowInput)

This change enables better functional composition where subflows can receive typed inputs without the run wrapper that previously blocked type matching. The asymmetric input pattern makes the API more intuitive while maintaining full type safety.

Key Changes:

• Updated StepInput utility type to implement the asymmetric pattern
• Modified step handler signatures to use flowInput instead of input.run
• Added flowInput to the FlowContext interface for dependent steps
• Updated all tests to use the new pattern
• Improved type tests to verify the asymmetric behavior

This change is backward compatible at runtime but will require updating handler parameter names in client code. The improved type safety and composability are worth the minor migration effort.

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Latest commit: b47e937

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[jumski]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• docs: add note about CONNECT_TIMEOUT fix using jsr:@oscar6echo/postgres fork #562
• fix: reject empty dependsOn arrays and improve flowInput access patterns #561
• feat: make flowInput lazy-loaded to prevent data duplication in map steps #560
• feat: asymmetric handler signatures for simpler flow composition #559
• refactor: simplify step input structure by removing run key and using context.flowInput #558
• refactor: rename input parameters to flowInput and deps for clarity #557
• refactor: change step handler input to use asymmetric pattern for better type safety #556 👈 (View in Graphite)
• feat: add flow_input to StepTaskRecord and context objects #555
• feat: add flow_input field to step_task_record for direct access to original input #554
• main

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[nx-cloud]

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☁️ Nx Cloud last updated this comment at 2025-12-23 08:27:25 UTC