build: fix types and support `image.cdn` or `image.url`

eleventy/data.ts

···
+import { type Dict } from './type-utils';
+
+interface ItemData {
+   title?: string;
+   subtitle?: string;
+   summary?: string;
+   tags?: string[];
+   date?: string | Date;
+   started?: string | Date;
+   updated?: string | Date;
+   updates?: Array<Update>;
+   qualifiers?: Qualifiers;
+   image?: Image;
+   link?: string;
+   splash?: string;
+   book?: Book;
+   standalonePage?: boolean;
+   featured?: boolean;
+   draft?: boolean;
+   /**
+    * Allow overriding the normal feed ID to enable keeping feed entries stable even if
+    * the slug changes.
+    */
+   feedId?: string;
+   /** Markdown-enabled thanks to people who contributed to the thing. */
+   thanks?: string;
+   discuss?: {
+      hn: string;
+      lobsters: string;
+   };
+   sendEmail?: boolean;
+   feedOnly?: boolean;
+}
+
+/** Extending the base Eleventy item with my own data */
+declare module '../types/eleventy' {
+   interface Data extends ItemData {}
+}
+
+type Image = string | { cdn: string } | { url: string };
+
+export function imageValue(
+   data: Pick<ItemData, 'image' | 'book'> | undefined,
+): string | undefined {
+   if (!data) return undefined;
+
+   if (typeof data.image == 'string') return data.image;
+
+   if (typeof data.image == 'object' && data.image != null) {
+      console.log(JSON.stringify(data.image));
+      let x =
+         'cdn' in data.image
+            ? `https://cdn.chriskrycho.com/images/${data.image.cdn}`
+            : data.image.url;
+      console.log(x);
+      return x;
+   }
+
+   if (typeof data.book == 'object' && data.book != null) return data.book.cover;
+
+   return undefined;
+}
+
+export type Author = { author: string } | { authors: string[] };
+
+export interface Review {
+   review?: {
+      rating:
+         | 'Required'
+         | 'Recommended'
+         | 'Recommended With Qualifications'
+         | 'Not Recommended';
+      summary: string;
+   };
+}
+
+export interface BookMeta {
+   title: string;
+   year?: number | string;
+   cover?: string;
+   link?: string;
+}
+
+// Must be a `type` alias because interfaces cannot extend unions.
+export type Book = BookMeta & Author & Review;
+
+export function isBook(maybeBook: unknown): maybeBook is Book {
+   if (typeof maybeBook !== 'object' || !maybeBook) {
+      return false;
+   }
+
+   const maybe = maybeBook as Dict<unknown>;
+
+   return (
+      typeof maybe.title === 'string' &&
+      (typeof maybe.author === 'string' || Array.isArray(maybe.authors)) &&
+      (typeof maybe.year == 'number' || typeof maybe.year === 'string') &&
+      typeof maybe.review === 'object' &&
+      typeof maybe.cover === 'string' &&
+      typeof maybe.link === 'string'
+   );
+}
+
+export interface Update {
+   at: string | Date;
+   changes: string;
+}
+
+export interface Qualifiers {
+   audience?: string;
+   context?: string;
+   epistemic?: string;
+   discusses?: string[];
+}

eleventy/feed.ts

···
 import { DateTime } from 'luxon';
 import { Maybe, Result } from 'true-myth';
 
-import { Dict, EleventyClass, Item } from '../types/eleventy';
+import { EleventyClass, Item } from '../types/eleventy';
 import JsonFeed, { FeedItem } from '../types/json-feed';
 import absoluteUrl from './absolute-url';
 import { canParseDate } from './date-time';
···
 import markdown from './markdown';
 import localeDate from './locale-date';
 import niceList from './nice-list';
+import { type Book, imageValue, isBook, type Qualifiers } from './data';
 
 type BuildInfo = typeof import('../site/_data/build');
 type SiteConfig = typeof import('../site/_data/config');
···
 /** Defensive function in case handed bad data */
 const optionalString = (value: unknown): string | undefined =>
    typeof value === 'string' ? value : undefined;
-
-type Author = { author: string } | { authors: string[] };
-
-interface Review {
-   review?: {
-      rating:
-         | 'Required'
-         | 'Recommended'
-         | 'Recommended With Qualifications'
-         | 'Not Recommended';
-      summary: string;
-   };
-}
-
-interface BookMeta {
-   title: string;
-   year?: number | string;
-   cover?: string;
-   link?: string;
-}
-
-// Must be a `type` alias because interfaces cannot extend unions.
-type Book = BookMeta & Author & Review;
-
-interface Update {
-   at: string | Date;
-   changes: string;
-}
-
-/** Extending the base Eleventy item with my own data */
-declare module '../types/eleventy' {
-   interface Data {
-      title?: string;
-      subtitle?: string;
-      summary?: string;
-      tags?: string[];
-      date?: string | Date;
-      started?: string | Date;
-      updated?: string | Date;
-      updates?: Array<Update>;
-      qualifiers?: Qualifiers;
-      image?: string;
-      link?: string;
-      splash?: string;
-      book?: Book;
-      standalonePage?: boolean;
-      featured?: boolean;
-      draft?: boolean;
-      /**
-       * Allow overriding the normal feed ID to enable keeping feed entries stable even if
-       * the slug changes.
-       */
-      feedId?: string;
-      /** Markdown-enabled thanks to people who contributed to the thing. */
-      thanks?: string;
-      discuss?: {
-         hn: string;
-         lobsters: string;
-      };
-      sendEmail?: boolean;
-      feedOnly?: boolean;
-   }
-}
-
-interface Qualifiers {
-   audience?: string;
-   context?: string;
-   epistemic?: string;
-   discusses?: string[];
-}
-
-function isBook(maybeBook: unknown): maybeBook is Book {
-   if (typeof maybeBook !== 'object' || !maybeBook) {
-      return false;
-   }
-
-   const maybe = maybeBook as Dict<unknown>;
-
-   return (
-      typeof maybe.title === 'string' &&
-      (typeof maybe.author === 'string' || Array.isArray(maybe.authors)) &&
-      (typeof maybe.year == 'number' || typeof maybe.year === 'string') &&
-      typeof maybe.review === 'object' &&
-      typeof maybe.cover === 'string' &&
-      typeof maybe.link === 'string'
-   );
-}
 
 const joinAuthors = (authors: string[]): Result<string, string> => {
    switch (authors.length) {
···
                  item.data?.updated instanceof Date
                     ? isoDate(item.data.updated)
                     : undefined,
-              image: optionalString(item.data?.image ?? item.data?.book?.cover),
+              image: imageValue(item.data),
               external_url: optionalString(item.data?.link ?? item.data?.book?.link),
               tags: Array.isArray(item.data?.tags) ? item.data?.tags : [],
               banner_image:

eleventy/type-utils.ts

···
+// ---- Utility types
+export interface Dict<T = unknown> {
+   [key: string]: T | undefined;
+}
+
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export type AnyFunction<T = any> = (...args: any[]) => T;

site/_includes/components/social.njk

···
 
    {%- set image -%}
       {%- if page.data.image -%}
-         {{page.data.image}}
+         {%- if page.data.image.cdn -%}
+            https://cdn.chriskrycho.com/images/{{page.data.image.cdn}}
+         {%- elif page.data.image.url -%}
+            {{page.data.image.url}}
+         {%- else -%}
+            {{page.data.image}}
+         {%- endif -%}
       {%- elif page.data.book.cover -%}
          {{page.data.book.cover}}
       {%- elif pageTitle -%}

types/eleventy.d.ts

···
 type ServeStaticOptions = import('serve-static').ServeStaticOptions;
 
-// ---- Utility types
-interface Dict<T = unknown> {
-   [key: string]: T | undefined;
-}
-
-// eslint-disable-next-line @typescript-eslint/no-explicit-any
-type AnyFunction<T = any> = (...args: any[]) => T;
-
 // ---- Eleventy types
 interface BrowserSyncConfig {
    /** Browsersync includes a user-interface that is accessed via a separate port. The UI allows to controls all devices, push sync updates and much more. */
···
 
 type Empty = { isEmpty: true; empty: string } | { isEmpty: false };
 
+import { AnyFunction, Dict } from '../eleventy/type-utils';
 import type { GrayMatterFile, GrayMatterOption } from 'gray-matter';
 
 export type Engine = (input: string) => GrayMatterFile<string>;
···
       In addition to Global Data Files global data can be added to the Eleventy
       config object using the `addGlobalData` method. This is especially useful
       for plugins.
-   
+
       The first value of `addGlobalData` is the key that will be available to
       your templates and the second value is the value of the value returned to
       the template.