samples-sinatra-postgres.md

id	samples-sinatra-postgres
title	Sample User CRUD App (Sinatra + Postgres)
sidebar_label	Sinatra + Postgres
description	A sample User CRUD application built with Ruby Sinatra and PostgreSQL to demonstrate how Keploy records API calls and database interactions automatically.
tags	sinatra ruby quickstart samples examples tutorial ruby-framework postgresql
keyword	Sinatra Framework Ruby PostgreSQL API Test generator Auto case generation

import ProductTier from '@site/src/components/ProductTier';

Get started with the User CRUD Application.

import Link from '@docusaurus/Link' import EnterpriseInstallReminder from '@site/src/components/EnterpriseInstallReminder';

Get Started

Clone the application

git clone https://github.com/keploy/samples-ruby.git && cd samples-ruby/sinatra-postgres

Capture the test cases

Capture the test cases:

keploy record -c "docker compose up" --container-name "sinatra-app" --buildDelay 50

Generate testcases

To generate testcases we need to make some API calls. Open a new terminal window and run the following commands:

1. Health check:

curl http://localhost:4567/

2. Create a user:

curl -X POST http://localhost:4567/users \
-H "Content-Type: application/json" \
-d '{"name": "John Doe", "email": "john@example.com"}'

3. Create another user:

curl -X POST http://localhost:4567/users \
-H "Content-Type: application/json" \
-d '{"name": "Jane Smith", "email": "jane@example.com"}'

4. Get all users:

curl http://localhost:4567/users

5. Get a specific user:

curl http://localhost:4567/users/1

6. Delete a user:

curl -X DELETE http://localhost:4567/users/2

Once you are done, you can stop the recording in the first terminal (Ctrl+C). Keploy will save the test cases in the keploy directory.

Run the testcases

keploy test -c "docker compose up" --containerName "sinatra-app" --delay 10

You can also check the test summary from your CLI.

Running App Locally on Linux/WSL

Prerequisites

• Ruby 3.0+ installed
• PostgreSQL installed and running
• Keploy installed

Setup

1. Start PostgreSQL Container:

Since we are running the app locally, we need a database. We can spin up a PostgreSQL container easily:

docker run -d \
  --name postgres-local \
  -p 5432:5432 \
  -e POSTGRES_PASSWORD=postgres \
  -e POSTGRES_DB=keploy_demo \
  postgres:15

2. Install dependencies:

bundle install

3. Set up environment variables:

Note: We use 127.0.0.1 instead of localhost to ensure IPv4 connection.

export DATABASE_HOST=127.0.0.1
export DATABASE_PORT=5432
export DATABASE_NAME=keploy_demo
export DATABASE_USER=postgres
export DATABASE_PASSWORD=postgres

Record Test Cases

keploy record -c "bundle exec ruby app.rb"

Then make API calls as shown above (in a separate terminal).

Run Tests

keploy test -c "bundle exec ruby app.rb" --delay 5

Conclusion

You have successfully recorded and replayed API tests for a Ruby Sinatra application using Keploy.