后端建立 TypeScript 构建链路

apps/backend/src/db/client.ts

@@ -1,10 +1,11 @@
 import { Pool } from 'pg'
+import type { PoolClient, QueryResult, QueryResultRow } from 'pg'
 
 import { runtimeConfig } from '../config/runtime.js'
 
-let poolInstance = null
+let poolInstance: Pool | null = null
 
-export function getDb() {
+export function getDb(): Pool {
   if (!poolInstance) {
     poolInstance = new Pool({
       connectionString: String(runtimeConfig.database?.url || '').trim(),
@@ -16,12 +17,20 @@ export function getDb() {
   return poolInstance
 }
 
-export async function query(text, params = []) {
+export async function query(text: string, params?: unknown[]): Promise<QueryResult<any>>
+export async function query<T extends QueryResultRow>(
+  text: string,
+  params?: unknown[],
+): Promise<QueryResult<T>>
+export async function query<T extends QueryResultRow>(
+  text: string,
+  params: unknown[] = [],
+): Promise<QueryResult<T>> {
   const pool = getDb()
-  return pool.query(text, params)
+  return pool.query<T>(text, params)
 }
 
-export async function withTransaction(fn) {
+export async function withTransaction<T>(fn: (client: PoolClient) => Promise<T>): Promise<T> {
   const client = await getDb().connect()
 
   try {
@@ -37,7 +46,7 @@ export async function withTransaction(fn) {
   }
 }
 
-export async function closeDb() {
+export async function closeDb(): Promise<void> {
   if (!poolInstance) {
     return
   }