Refactor for Testability | Dataford Interview Questions

Refactor this component to improve its testability.

Extract the component's deterministic state transformation into build_component_view_model(props). The function must not access browser globals, perform I/O, mutate props, or depend on rendering state. Return a view model containing enabled items, the valid selected item, and whether the empty state should be shown.

Input props is a dictionary with items, a list of {id, label, enabled} objects, and selectedId, which may be null. Return {visibleItems, selectedId, showEmptyState}.

Constraints

props contains an items list and may contain a null or missing selectedId
Each item contains unique id, string label, and boolean enabled fields
The input must not be mutated
Preserve the original order of enabled items

Function Signature

def build_component_view_model(props):

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Problem

Refactor this component to improve its testability.

Input props is a dictionary with items, a list of {id, label, enabled} objects, and selectedId, which may be null. Return {visibleItems, selectedId, showEmptyState}.

Constraints

props contains an items list and may contain a null or missing selectedId
Each item contains unique id, string label, and boolean enabled fields
The input must not be mutated
Preserve the original order of enabled items

Function Signature

def build_component_view_model(props):

Your question is Refactor for Testability. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.