Add buildDatabaseUrl and a CLI helper to print it

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

scripts/printDatabaseUrl.js

@@ -0,0 +1,4 @@
+import { loadConfig } from '../src/config.js';
+import { buildDatabaseUrl } from '../src/db.js';
+
+console.log(buildDatabaseUrl(loadConfig()));

src/db.js

@@ -2,6 +2,11 @@ import mariadb from 'mariadb';
 
 let pool;
 
+export function buildDatabaseUrl(config) {
+  const { host, user, password, database } = config.db;
+  return `mysql://${encodeURIComponent(user)}:${encodeURIComponent(password)}@${host}:3306/${database}?connection_limit=10`;
+}
+
 export function getPool(config) {
   if (!pool) {
     pool = mariadb.createPool({

test/db.test.js

@@ -1,7 +1,25 @@
 import { describe, it, expect, afterAll } from 'vitest';
-import { getPool, closePool } from '../src/db.js';
+import { getPool, closePool, buildDatabaseUrl } from '../src/db.js';
 import { loadConfig } from '../src/config.js';
 
+describe('buildDatabaseUrl', () => {
+  it('builds a mysql connection string from db config', () => {
+    const url = buildDatabaseUrl({
+      db: { host: '127.0.0.1', user: 'convert_user', password: 'change_me', database: 'file_converter' },
+    });
+
+    expect(url).toBe('mysql://convert_user:change_me@127.0.0.1:3306/file_converter?connection_limit=10');
+  });
+
+  it('percent-encodes special characters in user and password', () => {
+    const url = buildDatabaseUrl({
+      db: { host: '127.0.0.1', user: 'a@b', password: 'p@ss:word', database: 'file_converter' },
+    });
+
+    expect(url).toBe('mysql://a%40b:p%40ss%3Aword@127.0.0.1:3306/file_converter?connection_limit=10');
+  });
+});
+
 describe('getPool', () => {
   afterAll(async () => {
     await closePool();