Fix SQL syntax and add user registration test

Corrected a SQL syntax error in the databaseGlobals.js by removing an extraneous comma. Added a test script (test.js) to initialize the database and test user registration functionality.

modules/databaseGlobals.js

@@ -68,7 +68,7 @@ function initializeDatabase() {
             
             FOREIGN KEY(productId)
                 REFERENCES products(id)
-                ON DELETE CASCADE,
+                ON DELETE CASCADE
         )
     `)
 }

test.js

@@ -0,0 +1,19 @@
+const globals = require("./modules/databaseGlobals")
+const userService = require("./services/userService")
+
+async function main() {
+    globals.initializeDatabase()
+    try {
+        const result = await userService.register({
+            firstName: "User",
+            lastName: "Root",
+            username: "admin",
+            password: "changme"
+        })
+        console.log(result)
+    } catch (error) {
+        console.error(error)
+    }
+}
+
+main()