feat: add persistent store, atomic 0600 writes

src/config/store.ts

@@ -0,0 +1,50 @@
+import { existsSync, mkdirSync, readFileSync, renameSync, writeFileSync } from 'node:fs'
+import { homedir } from 'node:os'
+import { dirname, join } from 'node:path'
+import { type ConnectionConfig, connectionConfigSchema } from './types.js'
+
+export const defaultStorePath = (env: NodeJS.ProcessEnv = process.env): string =>
+    env.DBMOLE_STORE ?? join(homedir(), '.config', 'dbmole', 'connections.json')
+
+export const parseConnections = (items: unknown[], origin: string): ConnectionConfig[] => {
+    const result: ConnectionConfig[] = []
+    for (const item of items) {
+        const check = connectionConfigSchema.safeParse(item)
+        if (check.success) {
+            result.push(check.data)
+        } else {
+            const name = (item as { name?: unknown })?.name ?? '<unnamed>'
+            console.error(`dbmole: skipping invalid connection '${String(name)}' from ${origin}`)
+        }
+    }
+    return result
+}
+
+export const readStore = (path: string): ConnectionConfig[] => {
+    mkdirSync(dirname(path), { recursive: true, mode: 0o700 })
+    if (!existsSync(path)) return []
+    let parsed: unknown
+    try {
+        parsed = JSON.parse(readFileSync(path, 'utf8'))
+    } catch {
+        console.error(`dbmole: store file ${path} is not valid JSON, treating as empty`)
+        return []
+    }
+    if (!Array.isArray(parsed)) {
+        console.error(`dbmole: store file ${path} must contain a JSON array, treating as empty`)
+        return []
+    }
+    return parseConnections(parsed, `store ${path}`)
+}
+
+let writeSeq = 0
+
+export const writeStore = (path: string, connections: ConnectionConfig[]): void => {
+    mkdirSync(dirname(path), { recursive: true, mode: 0o700 })
+    writeSeq += 1
+    const tmp = `${path}.${process.pid}.${writeSeq}.tmp`
+    const items = connections.map((c) => JSON.stringify(c, null, 4))
+    const content = items.length === 0 ? '[]\n' : `[\n${items.join(',\n')}\n]\n`
+    writeFileSync(tmp, content, { mode: 0o600 })
+    renameSync(tmp, path)
+}