chore: import upstream snapshot with attribution

gemini/sample-apps/genwealth/api/database.ts

@@ -0,0 +1,59 @@
+import { Pool } from 'pg'
+import * as _ from 'lodash';
+
+/**
+ * Required ENV variables to be set:
+
+    PGPORT=5432
+    PGDATABASE=ragdemos
+    PGUSER=postgres
+    PGHOST=
+    PGPASSWORD=
+ */
+
+/**
+ * Converts SQL field names from snake_case to camelCase.
+ * 
+ * @param rows Rows from a database query
+ * @returns 
+ */
+export const camelCaseRows = (rows: any[]) => _.map(rows, (row) => 
+  _.mapKeys(row, (value, key) => _.camelCase(key)));
+
+/**
+ * Escapes single quotes in a string.
+ * 
+ * @param str String to be escaped
+ * @returns escaped string
+ */
+export const safeString = (str: string) => str?.replace(/'/g, "''") ?? '';
+
+
+export class Database {
+  private pool: Pool;
+
+  constructor() {
+    if (!process.env['PGHOST']) {
+      throw new Error(`Missing required environment variable: 'PGHOST'`);
+    }
+    this.pool = new Pool()
+
+    // the pool will emit an error on behalf of any idle clients
+    // it contains if a backend error or network partition happens
+    this.pool.on('error', (err, client) => {
+      console.error('Unexpected error on idle client', err);
+      throw err;
+    })
+  }
+
+  async query(query: string) {
+    const client = await this.pool.connect()
+    const res = await client.query(query)
+    client.release()
+    return res.rows;
+  }
+
+  async end() {
+    await this.pool.end()
+  }
+}