Analysis

Undefined initial value passed to prompts when linter preference is invalid

What fails: ThelinterIndexMap lookup inpackages/create-next-app/index.ts:321-324 returnsundefined whengetPrefOrDefault('linter') returns a value not in the map ('eslint', 'biome', 'none'), causing the prompts library to receiveinitial: undefined.

How to trigger:

1. Create or modify the create-next-app config with an invalid linter preference:

# Edit ~/.config/create-next-app/config.json to contain:{"preferences": {"linter":"invalid-value"}}

2. Run create-next-app without CLI linter flags to trigger the interactive prompt

Result: The prompts library receivesinitial: undefined instead of a valid array index, leading to unpredictable default selection behavior.

Expected: Should default to a valid index (0 = ESLint) when the preference value is not recognized, ensuring consistent user experience.

Fix applied: Added nullish coalescing operator?? 0 to provide fallback to first option (ESLint) when lookup returns undefined.