Function pickStaticIndexCSS

packages/core/src/css/planner.ts:11–33

(faces: FontFace[])

// Packages prefer a 400 weight normal face for `index.css`, but there are fonts
// which do not have weight 400, or are only italic.
const pickStaticIndexCSS = (faces: FontFace[]): string | undefined => {
	const findClosestFace = (candidates: readonly StaticFace[]) => {
		if (candidates.length === 0) {
			return undefined;
		}

		const weight = findClosestWeight(candidates.map((face) => face.weight));
		return candidates.find((face) => face.weight === weight);
	};

	const staticFaces = faces.filter(isStaticFace);
	const normalFaces = staticFaces.filter((face) => face.style === 'normal');

	const index = findClosestFace(normalFaces) ?? findClosestFace(staticFaces);

	if (!index) {
		return undefined;
	}

	return index.style === 'normal'
		? `${index.weight}.css`
		: `${index.weight}-${index.style}.css`;
};

const pickVariableIndexCSS = (
	variable: FontConfig['variable'],