FontDefinition

import type { FontDefinition } from "@shadow-js/dusk/vite";

interface FontDefinition {
  /** The family name the CSS uses. */
  readonly family: string;
  /** CSS custom property that holds the font stack, for example `--font-sans`. */
  readonly variable?: string;
  readonly files: readonly FontFile[];
  /** Generic and system families after the font. Default `["sans-serif"]`. */
  readonly fallback?: readonly string[];
  /** Default `swap`. */
  readonly display?: FontDisplay;
  /** Whether the family's files are preloaded unless a file says otherwise. Default true (see {@link FontFile.preload}). */
  readonly preload?: boolean;
  /**
   * The size-adjusted fallback face (the `size-adjust` technique), so the text does not jump when the web font arrives.
   *
   * Absent: the face is built when the metrics of the family's files can be read (Arial, or Times New Roman when the
   * `fallback` stack has `serif`), and left out, without an error, when they cannot. `false`: no fallback face.
   * An object asks for the face and makes an unreadable file an error: `local` is the system font it is built from
   * (`Arial`, `Times New Roman`); `font` defaults to the metrics the family's files declare (`readFontMetrics`, from the
   * file nearest to weight 400 that has the Latin letters); `fallback` defaults to the system font's measured values in
   * `SYSTEM_FALLBACKS`. Pass both to use other values (for example Next.js's capsize table).
   */
  readonly metrics?:
    | false
    | {
        readonly local: string;
        readonly font?: FontMetrics;
        readonly fallback?: { readonly unitsPerEm: number; readonly xWidthAvg: number };
      };
}