🎯 Your Tasks

Your assignment is to test this loan application API. Design a test suite, identify defects, and provide additional technical documentation where needed.

1. Write Comprehensive Tests

Using whatever language/framework you think is most appropriate, create a test suite that covers:

• Functional Tests: Happy path scenarios, CRUD operations
• Input Validation: Required fields, data types, formats
• Business Logic: Income thresholds, amount limits
• Error Handling: Invalid requests, non-existent resources

2. Find and Document Issues

Identify any issues or defects in the API behavior. Document your findings in TEST_RESULTS.md:

Include for each bug:

• Bug description and severity (Critical/High/Medium/Low)
• Steps to reproduce
• Expected vs actual behavior
• Request/response examples
• Business impact

3. Provide Test Documentation

In your TEST_RESULTS.md, include:

• Test execution instructions
• Bug report (see above)
• Test approach and strategy
• Framework choice justification
• Coverage summary

📮 Submission

1. Create a new branch: solution/[your-name]
2. Regularly commit your changes
3. Attach and email your completed code challenge to lindsay.sofield@reach.com

🚀 Getting Started

cd api
npm install
npm start

Server runs on http://localhost:3000

Note: The API starts with 5 pre-existing loan applications (APP-001 through APP-005) in various states for testing purposes.

📡 API Documentation

The Loan Application API provides endpoints for managing loan applications through their lifecycle. All endpoints return JSON responses.

Base URL: http://localhost:3000

---

POST /applications

Create a new loan application and get an immediate approval decision.

Request Body:

Field	Type	Required	Validation	Description
firstName	string	✅	Min 2 characters	Applicant's first name
lastName	string	✅	Min 2 characters	Applicant's last name
email	string	✅	Valid email format	Contact email address
income	number	✅	Positive number	Annual income in USD
amount	number	✅	Positive number	Requested loan amount in USD

Example Request:

POST /applications
Content-Type: application/json

{
  "firstName": "John",
  "lastName": "Doe",
  "email": "john.doe@example.com",
  "income": 50000,
  "amount": 15000
}

Success Response (201 Created):

{
  "id": "APP-001",
  "firstName": "John",
  "lastName": "Doe",
  "email": "john.doe@example.com",
  "income": 50000,
  "amount": 15000,
  "status": "approved",
  "decision": {
    "approved": true,
    "reason": "Income meets minimum requirements"
  },
  "createdAt": "2024-01-15T10:30:00.000Z"
}

Error Response (400 Bad Request):

{
  "error": "Validation failed",
  "details": [
    "firstName is required (min 2 characters)",
    "valid email is required"
  ]
}

---

GET /applications/:id

Retrieve a specific loan application by its ID.

Path Parameters:

Parameter	Type	Description
id	string	Application ID (e.g., "APP-001")

Example Request:

GET /applications/APP-001

Success Response (200 OK):

{
  "id": "APP-001",
  "firstName": "John",
  "lastName": "Doe",
  "email": "john.doe@example.com",
  "income": 50000,
  "amount": 15000,
  "status": "approved",
  "decision": {
    "approved": true,
    "reason": "Income meets minimum requirements"
  },
  "createdAt": "2024-01-15T10:30:00.000Z"
}

Error Response (404 Not Found):

{
  "error": "Application not found"
}

---

GET /applications

Retrieve all loan applications in the system.

Example Request:

GET /applications

Success Response (200 OK):

[
  {
    "id": "APP-001",
    "firstName": "John",
    "lastName": "Doe",
    "email": "john.doe@example.com",
    "income": 50000,
    "amount": 15000,
    "status": "approved",
    "decision": {
      "approved": true,
      "reason": "Income meets minimum requirements"
    },
    "createdAt": "2024-01-15T10:30:00.000Z"
  },
  {
    "id": "APP-002",
    "firstName": "Jane",
    "lastName": "Smith",
    "email": "jane@example.com",
    "income": 25000,
    "amount": 8000,
    "status": "rejected",
    "decision": {
      "approved": false,
      "reason": "Income below minimum threshold"
    },
    "createdAt": "2024-01-15T11:00:00.000Z"
  }
]

---

PUT /applications/:id/status

Update the status of an existing loan application.

Path Parameters:

Parameter	Type	Description
id	string	Application ID (e.g., "APP-001")

Request Body:

Field	Type	Required	Valid Values	Description
status	string	✅	pending, approved, rejected, funded	New status for the application

Example Request:

PUT /applications/APP-001/status
Content-Type: application/json

{
  "status": "funded"
}

Success Response (200 OK):

{
  "id": "APP-001",
  "firstName": "John",
  "lastName": "Doe",
  "email": "john.doe@example.com",
  "income": 50000,
  "amount": 15000,
  "status": "funded",
  "decision": {
    "approved": true,
    "reason": "Income meets minimum requirements"
  },
  "createdAt": "2024-01-15T10:30:00.000Z",
  "updatedAt": "2024-01-15T14:45:00.000Z"
}

Error Responses:

// 404 Not Found
{
  "error": "Application not found"
}

// 400 Bad Request
{
  "error": "Invalid status",
  "validStatuses": ["pending", "approved", "rejected", "funded"]
}

---

GET /health

Health check endpoint to verify the API is running.

Example Request:

GET /health

Success Response (200 OK):

{
  "status": "healthy",
  "timestamp": "2024-01-15T10:30:00.000Z"
}

---

HTTP Status Codes

Code	Meaning	When Used
200	OK	Successful GET, PUT requests
201	Created	Successful POST /applications
400	Bad Request	Validation errors, invalid data
404	Not Found	Application not found, invalid endpoint
500	Internal Server Error	Unexpected server errors

📊 Business Rules

Core Approval Logic

1. Income Requirements: Minimum income of $30,000/year (inclusive)
2. Loan Amount Limits: Between $1,000 and $50,000 (inclusive)
3. Required Fields: firstName, lastName, email, income, amount
4. Status Transitions:
   • pending → approved/rejected
   • approved → funded
   • No transitions from rejected or funded

Remember: This challenge simulates real-world API testing scenarios. We value practical solutions, clear communication, and attention to detail. Show us how you would approach this in your day-to-day work as a Senior SDET.

Good luck! 🚀