From 854f4af39370542f0061888f74a85439a8549167 Mon Sep 17 00:00:00 2001
From: Dave <ottonom@gmail.com>
Date: Mon, 21 Sep 2026 21:43:15 +0200
Subject: [PATCH] Added reader and diagnostics

---
 src/lib/content/load.ts       | 45 +++++++++++++++++++++++++++++++++++
 src/lib/content/reader.ts     |  5 ++++
 src/lib/content/types.ts      | 18 ++++++++++++++
 src/lib/diagnostics/index.ts  | 22 +++++++++++++++++
 src/lib/diagnostics/report.ts | 23 ++++++++++++++++++
 src/lib/diagnostics/types.ts  | 14 +++++++++++
 6 files changed, 127 insertions(+)
 create mode 100644 src/lib/content/load.ts
 create mode 100644 src/lib/content/reader.ts
 create mode 100644 src/lib/content/types.ts
 create mode 100644 src/lib/diagnostics/index.ts
 create mode 100644 src/lib/diagnostics/report.ts
 create mode 100644 src/lib/diagnostics/types.ts

diff --git a/src/lib/content/load.ts b/src/lib/content/load.ts
new file mode 100644
index 0000000..9e41e53
--- /dev/null
+++ b/src/lib/content/load.ts
@@ -0,0 +1,45 @@
+import { ARTICLES, PAGES, TAGS } from '../constants/collections'
+import { createDiagnostics } from '../diagnostics'
+import type { Diagnostics } from '../diagnostics/types'
+import { createContentReader } from './reader'
+import type { ArticleEntry, Content, PageEntry, TagEntry } from './types'
+
+interface CollectionReader<T> {
+  list(): Promise<string[]>
+  read(id: string): Promise<T | null>
+}
+
+function reason(error: unknown): string {
+  const [first, ...rest] = (error instanceof Error ? error.message : String(error)).split('\n')
+  return first.endsWith(':') && rest.length ? rest.join('; ') : first
+}
+
+async function readAll<T>(
+  reader: CollectionReader<T>,
+  collection: string,
+  problems: Diagnostics,
+): Promise<Map<string, T>> {
+  const entries = new Map<string, T>()
+  await Promise.all(
+    (await reader.list()).map(async (id) => {
+      try {
+        const entry = await reader.read(id)
+        if (entry) entries.set(id, entry)
+      } catch (error) {
+        problems.error(collection, id, reason(error))
+      }
+    }),
+  )
+  return entries
+}
+
+export async function loadContent(): Promise<Content> {
+  const { collections } = createContentReader()
+  const problems = createDiagnostics()
+  const [articles, pages, tags] = await Promise.all([
+    readAll<ArticleEntry>(collections.articles, ARTICLES, problems),
+    readAll<PageEntry>(collections.pages, PAGES, problems),
+    readAll<TagEntry>(collections.tags, TAGS, problems),
+  ])
+  return { articles, pages, tags, diagnostics: problems.list }
+}
diff --git a/src/lib/content/reader.ts b/src/lib/content/reader.ts
new file mode 100644
index 0000000..dc4cdd4
--- /dev/null
+++ b/src/lib/content/reader.ts
@@ -0,0 +1,5 @@
+import { createReader } from '@keystatic/core/reader'
+
+import config from '~/keystatic.config'
+
+export const createContentReader = () => createReader('.', config)
diff --git a/src/lib/content/types.ts b/src/lib/content/types.ts
new file mode 100644
index 0000000..76fb8ab
--- /dev/null
+++ b/src/lib/content/types.ts
@@ -0,0 +1,18 @@
+import type { Entry } from '@keystatic/core/reader'
+
+import type config from '~/keystatic.config'
+
+import type { Diagnostic } from '../diagnostics/types'
+
+type Collections = typeof config.collections
+
+export type ArticleEntry = Entry<Collections['articles']>
+export type PageEntry = Entry<Collections['pages']>
+export type TagEntry = Entry<Collections['tags']>
+
+export interface Content {
+  articles: Map<string, ArticleEntry>
+  pages: Map<string, PageEntry>
+  tags: Map<string, TagEntry>
+  diagnostics: Diagnostic[]
+}
diff --git a/src/lib/diagnostics/index.ts b/src/lib/diagnostics/index.ts
new file mode 100644
index 0000000..7a11c53
--- /dev/null
+++ b/src/lib/diagnostics/index.ts
@@ -0,0 +1,22 @@
+import type { Diagnostic, Diagnostics } from './types'
+
+export function createDiagnostics(): Diagnostics {
+  const list: Diagnostic[] = []
+  return {
+    list,
+    error: (collection, id, message) =>
+      list.push({
+        level: 'error',
+        collection,
+        id,
+        message,
+      }),
+    warning: (collection, id, message) =>
+      list.push({
+        level: 'warning',
+        collection,
+        id,
+        message,
+      }),
+  }
+}
diff --git a/src/lib/diagnostics/report.ts b/src/lib/diagnostics/report.ts
new file mode 100644
index 0000000..2047bdc
--- /dev/null
+++ b/src/lib/diagnostics/report.ts
@@ -0,0 +1,23 @@
+import type { Diagnostic } from './types'
+
+const SYMBOL = {
+  error: '✖',
+  warning: '▲',
+} as const
+
+const byLevelThenEntry = (a: Diagnostic, b: Diagnostic) =>
+  (a.level === b.level ? 0 : a.level === 'error' ? -1 : 1) ||
+  a.collection.localeCompare(b.collection) ||
+  (a.id ?? '').localeCompare(b.id ?? '')
+
+export function formatDiagnostics(list: Diagnostic[]): string {
+  return [...list]
+    .sort(byLevelThenEntry)
+    .map((d) => `${SYMBOL[d.level]} ${d.collection}/${d.id ?? '*'} ${d.message}`)
+    .join('\n')
+}
+
+export function assertNoErrors(list: Diagnostic[]): void {
+  const errors = list.filter((d) => d.level === 'error').length
+  if (errors) throw new Error(`Content has ${errors} error(s):\n${formatDiagnostics(list)}`)
+}
diff --git a/src/lib/diagnostics/types.ts b/src/lib/diagnostics/types.ts
new file mode 100644
index 0000000..55645e0
--- /dev/null
+++ b/src/lib/diagnostics/types.ts
@@ -0,0 +1,14 @@
+export type Level = 'error' | 'warning'
+
+export interface Diagnostic {
+  level: Level
+  collection: string
+  id: string | null
+  message: string
+}
+
+export interface Diagnostics {
+  list: Diagnostic[]
+  error(collection: string, id: string | null, message: string): void
+  warning(collection: string, id: string | null, message: string): void
+}