website-astro/src/content/config.ts

import { z, defineCollection } from "astro:content";

const articles = defineCollection({
	schema: {
		title: z.string(),
		subtitle: z.string(),
		lang: z.enum(["fr", "en"]),
		slug: z.string(),
		tags: z.array(z.string()), // An array of strings
		// Parse pubDate as a browser-standard `Date` object
		pubDate: z
			.string()
			.transform((str) => new Date(str))
			.optional(),
	},
});

export const collections = {
	// Don't forget 'quotes' for collection names containing dashes
	articles,
};