Quality Assurance Interview Questions

A developer needs to write a function for converting age (a whole number), into life period using the following algorithm:

• If age is zero, it should return INVALID,
• If age is greater than zero and less than 16, function should return CHILD,
• If age is greater than or equal to 16, function should return ADULT.

Define the optimal (effective and efficient) set of boundary test cases to test the function.

Your team is developing software for a thermostat controller that has a switch for turning the heat on and off.

The following algorithm has been implemented:

• If the heating switch is on:
  • If the measured temperature is equal to or higher than 23°C, the heat is turned off.
  • If the measured temperature is lower than 23°C, the heat is turned on.
• If the heating switch is off:
  • If the measured temperature falls below 5°C, the heat is turned on to prevent the water in the heating system from freezing.
  • Otherwise, the heat is turned off.

Define the optimal (effective and efficient) set of boundary test cases to adequately test the thermostat controller.

An online shop sells pet food and accessories. Customers can choose goods and conclude their orders on its website. The order is processed according to these rules:

• A customer enters his or her order and clicks SUBMIT. Depending on its total value, the order is set to either of the following states:
  • APPROVED, if the value is less than or equal to $100.
  • PENDING, if the value is greater than $100 and the shop's personnel have to verify the validity of the online payment.
• For PENDING orders, shop personnel can click one of the following:
  • APPROVE if the payment is confirmed, thereby setting the order to the state of APPROVED.
  • CANCEL if the payment is invalid, thereby setting the order to the state of CANCELED.
• For orders in an APPROVED state, the shop personnel choose the SHIP action after the goods are actually sent, thereby setting the order to a state of SHIPPED.

Prepare the optimal (effective and efficient) set of test cases, each containing either a complete or partial state lifecycle, required to test this system.

An informational interest rate calculator for a fixed term deposit needs to be tested. For a given deposit amount and the client’s age, the calculator shows the annual interest rate.

The following rules apply:

• The minimum deposit amount is $100.
• The maximum deposit amount is $10,000.
• The annual interest rate depends on the deposit amount as follows:

  Deposit amount	Annual interest rate
  $100 - $999	1.0%
  $1,000 - $4,999	1.3%
  $5,000 - $10,000	1.5%

• Only adults (aged 18 and older) are eligible to open a term deposit account.
• Clients aged 60 and older have a fixed interest rate of 2%.

Define the optimal (effective and efficient) set of boundary test cases for a system that calculates the term's deposit interest.

The workflow of an ATM is defined by the following rules:

• The ATM goes into the WORKING state with the TURN ON action.
• When in the WORKING state, the ATM can:
  • ACCEPT CARD which switches it to the CARD ACCEPTED state.
  • Start the AUTOMATIC TESTING action which switches it to the SELF TESTING state.
• Within CARD ACCEPTED the ATM can:
  • CALL POLICE which switches it to the WAITING POLICE state.
  • PROCESS TRANSACTION which switches it to the TRANSACTION PROCESSED state.
• From the TRANSACTION PROCESSED state the ATM goes into the SELF TESTING state with the PULL CARD action.
• When in the SELF TESTING state, the ATM can either:
  • PASS, which switches it to the WORKING state.
  • FAIL, which switches it to the WAITING SERVICE state.
• From the WAITING SERVICE state, the ATM can either:
  • Be SERVICED, which puts the ATM into the WORKING state.
  • Be RETESTED, which returns the ATM to the SELF TESTING state.

Prepare the optimal (effective and efficient) set of test cases required to test this workflow. The test cases should cover all complete state transitions and should avoid testing same state transitions multiple times.