shadcn-errors-react-day-picker-v9

What problem does it solve?

It diagnoses why a shadcn UI Calendar that wraps react-day-picker v9 silently breaks after a dependency upgrade—showing blank rendering, missing selection, unstyled grids, ignored custom components, or confusing TypeScript errors.

Core Features & Use Cases

• Prop rename + behavior mapping: Converts common react-day-picker v8 API shapes (selectedDays, disabledDays, modifiers as arrays, Caption/IconLeft/IconRight, fromMonth/toMonth) into the correct v9 equivalents (selected, disabled, modifiers object of Matchers, MonthCaption/Chevron, startMonth/endMonth).
• Silent-failure symptom triage: Provides a symptom-to-fix matrix so you can match what you see (unstyled table, no selection, matcher warnings, boundary props ignored) to the exact v8→v9 cause.
• Production recovery guidance: Documents the canonical fix when the shadcn-side calendar source is stale by regenerating the component with the CLI overwrite flow.
• TypeScript error interpretation: Explains the specific “mode” discriminator requirement and other error messages that indicate the v9 contract is being violated.

Quick Start

Run the v9 migration check for the broken Calendar and rewrite any v8-shaped props to their v9 replacements, ensuring you set mode="single", mode="multiple", or mode="range" and rekey classNames to v9 UI keys.