feat: add env and config-file sources

src/config/sources.ts

@@ -0,0 +1,47 @@
+import { existsSync, readFileSync } from 'node:fs'
+import { parseConnections } from './store.js'
+import type { ConnectionConfig } from './types.js'
+
+export const readEnvConnections = (env: NodeJS.ProcessEnv = process.env): ConnectionConfig[] => {
+    const raw = env.DBMOLE_CONNECTIONS
+    if (!raw) {
+        return []
+    }
+    let parsed: unknown
+    try {
+        parsed = JSON.parse(raw)
+    } catch {
+        console.error('dbmole: DBMOLE_CONNECTIONS is not valid JSON, ignoring')
+        return []
+    }
+    if (!Array.isArray(parsed)) {
+        console.error('dbmole: DBMOLE_CONNECTIONS must be a JSON array, ignoring')
+        return []
+    }
+    return parseConnections(parsed, 'env DBMOLE_CONNECTIONS')
+}
+
+export const readConfigFile = (path: string | undefined): ConnectionConfig[] => {
+    if (!path) {
+        return []
+    }
+    if (!existsSync(path)) {
+        console.error('dbmole: config file ' + path + ' not found, ignoring')
+        return []
+    }
+    let parsed: unknown
+    try {
+        parsed = JSON.parse(readFileSync(path, 'utf8'))
+    } catch {
+        console.error('dbmole: config file ' + path + ' is not valid JSON, ignoring')
+        return []
+    }
+    const connections = (parsed as { connections?: unknown }).connections
+    if (!Array.isArray(connections)) {
+        console.error(
+            'dbmole: config file ' + path + ' must contain { "connections": [...] }, ignoring'
+        )
+        return []
+    }
+    return parseConnections(connections, 'config ' + path)
+}