mattrguerra/meridian-ops-boardmainPrivate on GitHub, published here in full

history-file.ts

Language TypeScript1.9 KB48 lines

apps/dashboard/src/history-file.ts

/**
* Reading and writing `data/dashboard-history.json`. Node only.
*
* Split out of history.ts because the Cloudflare Worker needs `rowFrom`,
* `previousRun` and `delta` but has no filesystem, and a static `node:fs` import
* resolves whether or not the symbol is used. The Worker keeps the same rows in
* KV; only the storage differs.
*/
import { readFile, writeFile, mkdir } from 'node:fs/promises'
import { dirname } from 'node:path'
import { fileURLToPath } from 'node:url'
import { KEEP, type HistoryRow } from './history.js'
export const HISTORY_FILE = new URL('../../../data/dashboard-history.json', import.meta.url)
export async function readHistory(file: URL = HISTORY_FILE): Promise<HistoryRow[]> {
try {
const parsed: unknown = JSON.parse(await readFile(file, 'utf8'))
if (!Array.isArray(parsed)) return []
// A hand-edited or half-written file must not take the build down; a missing
// delta is a smaller problem than a dashboard that will not render.
return parsed.filter((r): r is HistoryRow => !!r && typeof r === 'object' && typeof (r as HistoryRow).day === 'string')
} catch {
return []
}
}
/**
* Append today's row, replacing any earlier row for the same day, and trim.
* Returns the rows as they were before this run, so the caller can diff against
* them without racing itself.
*/
export async function recordRun(
row: HistoryRow,
file: URL = HISTORY_FILE,
): Promise<HistoryRow[]> {
const before = await readHistory(file)
const kept = before.filter((r) => r.day !== row.day)
const next = [...kept, row].sort((a, b) => a.day.localeCompare(b.day)).slice(-KEEP)
try {
await mkdir(dirname(fileURLToPath(file)), { recursive: true })
await writeFile(file, `${JSON.stringify(next, null, 2)}\n`, 'utf8')
} catch {
// Read-only checkout, CI, whatever. Deltas stop working; nothing else does.
}
return before
}