Make pg-native an optional dependency and handle its absence gracefully

lib/createdb.js

@@ -1,8 +1,17 @@
 #!/usr/bin/env node
 const args = require("commander");
 const packageInfo = require("../package");
-var postgresClient = require("pg-native");
-var sqlite3 = require("sqlite3");
+
+// Attempt to require "pg-native" as an optional dependency.
+let postgresClient;
+try {
+  postgresClient = require("pg-native");
+} catch (err) {
+  // pg-native not installed or cannot be loaded
+  postgresClient = null;
+}
+
+const sqlite3 = require("sqlite3");
 
 args
   .version(packageInfo.version)
@@ -36,7 +45,13 @@ CREATE TABLE gxitproxy
 };
 
 const createDbPostgres = function (sessions) {
-  const db = postgresClient();
+  if (!postgresClient) {
+    console.error(
+      "Error: pg-native is not installed. Cannot create PostgreSQL database.",
+    );
+    process.exit(1);
+  }
+  const db = new postgresClient();
   db.connectSync(sessions);
   db.querySync(`
     CREATE TABLE IF NOT EXISTS gxitproxy (
@@ -53,6 +68,8 @@ const createDbPostgres = function (sessions) {
 const main = function (argv_) {
   const argv = argv_ || process.argv;
   args.parse(argv);
+
+  // If sessions is a PostgreSQL connection string and pg-native is missing, exit.
   if (args.sessions.startsWith("postgresql://")) {
     createDbPostgres(args.sessions);
   } else {

lib/mapper.js

@@ -1,7 +1,14 @@
-var fs = require("fs");
-var sqlite3 = require("sqlite3");
-var postgresClient = require("pg-native");
-var watchFile = require("node-watch");
+const fs = require("fs");
+const sqlite3 = require("sqlite3");
+const watchFile = require("node-watch");
+
+let postgresClient;
+try {
+  postgresClient = require("pg-native");
+} catch (err) {
+  // pg-native not installed or cannot be loaded
+  postgresClient = null;
+}
 
 var updateFromJson = function (path, map) {
   var content = fs.readFileSync(path, "utf8");
@@ -84,7 +91,11 @@ var updateFromSqlite = function (path, map) {
 };
 
 var updateFromPostgres = function (path, map) {
-  var db = postgresClient();
+  if (!postgresClient) {
+    console.error("Error: pg-native is not installed. Cannot update from PostgreSQL database.");
+    process.exit(1);
+  }
+  var db = new postgresClient();
   var loadedSessions = {};
   db.connectSync(path);
 
@@ -118,14 +129,18 @@ var updateFromPostgres = function (path, map) {
 };
 
 var watchPostgres = function (path, loadMap, pollingInterval) {
+  if (!postgresClient) {
+    console.error("Error: pg-native is not installed. Cannot watch PostgreSQL database.");
+    process.exit(1);
+  }
   // poll the database every `pollingInterval` seconds
   if (pollingInterval > 0) {
     setInterval(loadMap, pollingInterval);
   }
 
   // watch changes using PostgresSQL asynchronous notifications
   // (https://www.postgresql.org/docs/16/libpq-notify.html)
-  var db = postgresClient();
+  var db = new postgresClient();
   db.connect(path, function (err) {
     if (err) {
       throw err;

package.json

@@ -29,9 +29,11 @@
     "eventemitter3": "5.0.1",
     "http-proxy": "1.18.1",
     "node-watch": "0.7.4",
-    "pg-native": "^3.2.0",
     "sqlite3": "5.1.7"
   },
+  "optionalDependencies": {
+    "pg-native": "^3.2.0"
+  },
   "devDependencies": {
     "@eslint/js": "^9.17.0",
     "axios": "^1.7",