Chen Syin Yi - Project Portfolio

Overview

Sharkie is a desktop expense tracker application. The user interacts with it using a CLI, and it has a GUI created with JavaFX. It is written in Java, and has about 10 kLoC.

Summary of contributions

Major enhancement:
- Added lend command (Pull request #87)
  - What it does: Allows the user to record the amount of money lent to other people in Sharkie’s contact list.
  - Justification: This is one of the key features of Sharkie, which records the flow of money between the user and the people in Sharkie.
  - Highlights: This command involves both Transactions and Person models, considerations have to made on how to use both of the models without changing their purposes or properties.
- Added received command (Pull request #98)
  - What it does: Allows the user to record that a person, who the user lent to has returned the amount of money.
  - Justification: This is an essential update, which allows the user to remove the loans recorded by the lend command.
  - Highlights: Considerations were needed during the implementation of this feature, to preserve the immutable property of Person.
- Added user data storage (Pull request #95)
  - What it does: Stores user data, such as name, phone and e-mail address.
  - Justification: The storage of user data is important, as the user details are required during the use of remind and remindall commands.
  - Highlights: This update was challenging, an entire new storage need to be built to store the user data, as the data needed to be stored differs from those in the address book.
- Added remind and remindall command (Pull request #95)
  - What it does: Allows the user to send reminders to the people, who have not return the amount of money they lent, via email.
  - Justification: This is one of the main features of Sharkie, which allows the interaction between the user and the people in Sharkie’s contact list.
  - Highlights: The implementation of this feature was new to me, as it involves the usage of the internet and the connection to e-mail servers.
  - Credits: javax.mail is used in the implementation of this feature.
Minor enhancement:
- Make Sharkie sends a confirmation email to user to validate the user’s email address during user’s first login. (Pull request #249)
Code contributed: [Functional codes & Test codes]
Other contributions:
- Enhancements to existing features:
  - Add progress indicator for command execution, to indicate that the application is not hanging during execution of commands, which take some time to run, such as people remind. (Pull request #148)
  - Improved GUI of Edit User Data Window and Help Window. (Pull request #178)
  - Made people’s tags uneditable. (Pull request #183)
  - Bug fixing. (Pull request #178, #243)
- Project management:
  - Finalized and tagged v1.1 - v1.4 (4 versions) on Github.
  - Managed release of v1.2.1 - v1.4 (3 releases) on Github.
- Documentation:
  - Updated the product website’s heading and navigation bar. (Pull requests #44, #81)
  - Edited About, Features, Commands and FAQ sections of the User Guide. (Pull requests #49, #192)
  - Added use cases in the appendix. Updated Design, Implementation and Manual Testing sections of the Developer Guide. (Pull requests #51, #132, #134, #146 #192, #200)
- Community:
  - PRs reviewed (with non-trivial review comments). (Pull requests #92, #100, #102, #104, #115)
  - Reported bugs and suggestions for other teams. (Issues #1, #2, #3, #4, #5, #6, #7, #8, #9)

Contributions to the User Guide

Given below are sections I contributed to the User Guide. They showcase my ability to write documentation targeting end-users.

This user guide will help to ensure that you have all the information you need to utilise Sharkie to its fullest extent. Sharkie is a feature-filled expense tracker and all the information you need regarding its usage is available below.

If you need help starting up Sharkie, you can head on to Quick Start below to set it up.

If you want to find out more about the features provided by Sharkie, you can visit Features below.

If you need help regarding what commands Sharkie has, Commands below will guide you through Sharkie’s commands.

Note the following symbols and formatting used in this document:

Table 1. Symbols and formats used in this User Guide.
Symbol/ Format	Meaning
`command`	A grey highlight (called a mark-up) indicates that this is a command that can be typed into the command line and executed by the application.
`Enter`	This symbol indicates the enter button on the keyboard.
	This yellow box indicates the restrictions of each command.
	This symbol indicates warnings to take note of.
	This symbol indicates information that you need to know.
	This symbol indicates tips that can help you in your use of Sharkie.

Quick Start

Features

Expenditure and Income

If you are a university student who has started to manage your own money, but struggles to track your expenses or meet your saving goals, Sharkie would be a good application for you to start with.

Sharkie allows you to record what you have spent on for the month, and also notes down your income for the month to help you properly track your money flow!

You may visit [wallet-commands] to find out more on how to record expenses or incomes in Sharkie.

Commands

Adding a person: `add`

Suppose you want to add a new person to the contact list, the command you would enter is our people add command.

Format: people add n/<name> p/<phone number> e/<email address>

Command Format

The following are the restrictions of people add command, which you would need to take note of:

The <name> you entered should only contain alphanumeric characters and spaces.
The <phone number> you entered should only contain numbers and it should be at least 3 digits long.
The <email address> you entered should be in the format of local-part@domain.
- The local-part should only contain alphanumeric characters and these special characters, excluding the parentheses (!#$%&'*+/=?`{|}~^.-).
- The domain name must be at least 2 characters long, start and end with alphanumeric characters.

Example:

Suppose you want to add your new friend, "Joel", along with his phone number "91234567" and email "joel@example.com" into the contact list.
- The command you would enter is people add n/Joel p/91234567 e/joel@example.com.
- This adds a person named "Joel" into your contact, along with his phone number and e-mail address.

Expected Outcome:

Your new friend, "Joel" will be added into your contact list:

New person added: Joel Phone: 91234567 Email: joel@example.com You owe: $0.00 You lent: $0.00

Recording the money you received: `received`

Suppose you want to record that you have received the money for a certain loan (or for all loans) from your friend, the command you would enter is our people received command.

Format: people received <person’s index> [i/<loan’s index>]

Command Format

The following is the restrictions of people received command, which you would need to take note of:

The <person’s index> and <loan’s index> you entered should be positive integers, e.g. 1, 2, 3, …

The <person’s index> above refers to the index number shown in the displayed person list in Sharkie. It indicates a specific person in the contact list, who you received from.
Still confused? Find out more about what is a person’s index.

The <loan’s index> above refers to the index number shown in the displayed loans list in Sharkie. It indicates a specific loan under the person, which you received from.
Still confused? Find out more about what is a loan’s index.

Loans represent the amount of money you lend your friends.
Still confused? Find out more about the differences between debts and loans.

The <loan’s index> is optional. All loans will be removed for the indicated person if the <loan’s index> is not specified.

Example:

Suppose you want to record that you have received the money from "Joel", who is the second person in the contact list, for the first loan in his loans list.
- The command you would enter is people received 2 i/1.
- This records that you have received the money for the first loan of "Joel", the second person in the contact list.

Expected Outcome:

The first loan of "Joel" will be removed from his loans list and the unsettled loans of "Joel" will be shown.
```
Removed loan to Joel by $10.00. Joel now owes you $2.00.
```

Sending reminder to a friend: `remind`

Suppose you want to remind a friend to return unsettled loans to you through an email, the command you would enter is our people remind command.

Format: people remind <person’s index>

Command Format

The following are the restrictions of people remind command, which you would need to take note of:

The <person’s index> you entered should be a positive integer, e.g. 1, 2, 3, …

You would need to connect to the Internet and include your details in Sharkie before using this command. You can enter or edit your details at "Edit" > "Edit user’s data".

Before you enter the people remind command, please make sure that your friend’s email address is correct.

The <person’s index> above refers to the index number shown in the displayed person list in Sharkie. It indicates a specific person in the contact list, who you want to remind.
Still confused? Find out more about what is a person’s index.

Loans represent the amount of money you lend your friends.
Still confused? Find out more about the differences between debts and loans.

If you receive connection error messages during the execution of the people remind command, please visit how to resolve connection issues.

Example:

Suppose you want to remind "Daniel", who is the first person in your contact list to return you your money.
- The command you would enter is people remind 1.
- This requests Sharkie to send an email to "Daniel", the first person in your contact list.

Expected Outcome:

"Daniel" will receive a reminder from Sharkie via his email. You will also receive a carbon copy (CC) of the email sent to "Daniel":
```
Reminded Daniel to return $3.00!
Sharkie has sent a carbon copy (CC) of the reminder to your email!
```

Sending reminder to all friends: `remindall`

Suppose you want to remind all your friends in your contact list to return you your money, the command you would enter is our people remindall command.

Format: people remindall

You would need to connect to the Internet and include your details in Sharkie before using this command. You can enter or edit your details at "Edit" > "Edit user’s data".

Before you enter the people remindall command, please make sure that your friends' email addresses are correct.

Only your friends, who have unsettled loan(s) will be reminded. Your friends who have zero loans will not receive a reminder.

Loans represent the amount of money you lend your friends.
Still confused? Find out more about the differences between debts and loans.

If you receive connection error messages during the execution of people remindall command, please visit how to resolve connection issues.

Example:

Suppose you want to remind all your friends in your contact list who have yet to repay you.
- The command you would enter is people remindall.
- This requests Sharkie to send an email to everyone in your contact list who have yet to repay you.

Expected Outcome:

All your friends who have yet to repay you will receive a reminder from Sharkie via their emails. You will also receive a carbon copy (CC) of each of the emails sent to your friends:
```
Reminded Cheyanne to return $20.00!
Reminded Daniel to return $10.00!
Reminded Joel to return $30.75!
Sharkie has sent carbon copies (CC) of the reminders to your email!
```

Finding a person: `find`

Suppose you want to find a person in your contact list by a specific keyword, the command you would enter is our people find command.

Format: people find n/<keyword> [<keyword>…]
or people find p/<keyword> [<keyword>…]
or people find e/<keyword> [<keyword>…]
or people find t/<keyword> [<keyword>…]

Command Format

The following are the restrictions of people find command, which you would need to take note of:

You would not have to consider the case of the <keyword>, as it is case-insensitive.
The <keyword> you want to enter can be incomplete. For example, people find n/jo will display the persons whose name contains the keyword "jo", such as "Joel".
The <keyword> you entered should be one of the prefixes: name (n/), phone (p/), email (p/) or tag (t/).
- You may use the tag prefix t/ to find people with debts or loans in your contact list. Hence, Debt and Loan (case-insensitive) are the only tags, which you are allowed to use in people find command.

Debts represent the amount of money you owe your friends and loans represent the amount of money you lend your friends.
Still confused? Find out more about the differences between debts and loans.

Example #1:

Suppose you want to find your friends, who are called "Grace".
- The command you would enter is people find n/Grace.
- This requests Sharkie to list out the people with the name, "Grace".

Expected Outcome #1:

All your friends with the name, "Grace" will be listed out:
```
2 persons listed!
```

Example #2:

Suppose you want to find your friends with unsettled debt(s) or loan(s).
- The command you would enter is people find t/debt loan.
- This requests Sharkie to list out the people with unsettled debt(s) or loan(s).

Expected Outcome #2:

All your friends with unsettled debt(s) or loan(s) will be listed out:
```
2 persons listed!
```

Clearing all contacts : `clear`

Suppose you want to clear all the contacts in your contact list, the command you would enter is our people clear command.

Format: people clear

Example:

Suppose you want to clear all your contacts.
- The command you would enter is people clear.
- This requests Sharkie to delete all the contacts in your contact list.

Expected Outcome:

Sharkie will delete all the contacts and return an empty contact list.
```
Contact list has been cleared!
```

FAQ

How do I edit my user data?

Click on "Edit", then "Edit user’s data" on your menu bar.

Figure 1. Editing user data in Sharkie

What is a person’s index?

A person’s index is the index number shown in the displayed person list in Sharkie. It indicates a specific person in the contact list.

For example,

1 is the person’s index of Alex Yeoh, whereas
2 is the person’s index of Bernice Yu.

Figure 2. What is a person’s index?

What is a debt’s index or a loan’s index?

A debt’s index is the index number shown in a person’s displayed debts list, whereas a loan’s index is the index number shown in a person’s displayed loans list. A debt’s index indicates a specific debt of a person and a loan’s index indicated a specific loan of a person.

For example,

The debt’s index of the debt, Dinner | $12.00 | 1 APR 2020, under Bernice Yu is 1.
The loan’s index of the loan, Movie | $10.00 | 2 FEB 2020, under Bernice Yu is 1.

Figure 3. What is a debt’s index or a loan’s index?

What are the differences between debts and loans?

Debts are the amount of money you owe your friends and loans are the amount of money you lend your friends.

For example,

1 | Supper | $5.00 | 3 FEB 2020 under the "Debts" section, shown in the figure below represents what you owe "Syin Yi".
1 | Breakfast | $3.00 | 8 AUG 2018 under the "Loans" section, shown in the figure below represents what you lent to "Syin Yi".

Figure 4. Differences between debts and loans

Why do my `people remind` and `people remindall` commands take time to run?

As the people remind and people remindall commands rely on the connection to the internet and e-mail server, time is needed for the application to send a reminder.

How can I resolve the connection issues during the execution of `people remind` or `people remindall`?

You may try the suggestions below to resolve your connection issues:

If you receive an error message as the following:

Error occured while sending email:
Couldn't connect to host, port: smtp.gmail.com, 587; timeout -1
Please make sure that you are connected to the internet.

Please make sure that you are connected to the internet.

If you receive an error message as the following:
```
Error occured while sending email:
Could not convert socket to TLS
Please make sure that you are connected to the internet.
```
- Please make sure that your firewall or antivirus programme allows Sharkie to connect to SMTP port 587. Please add an exclusion to SMTP port 587 in your firewall or antivirus programme, if you have not done so.

Contributions to the Developer Guide

Given below are sections I contributed to the Developer Guide. They showcase my ability to write technical documentation and the technical depth of my contributions to the project.

Design

Model component

Figure 5. Structure of the Model Component

Figure 6. In-depth structure of the Model Manager

The ModelManager class diagram is drawn separately as it is too complicated to include all the details in the Model component diagram.

API : Model.java

The Model,

stores a UserPref object that represents the user’s preferences.
stores the Wallet data.
stores the Address Book data.
stores the User data.
exposes an unmodifiable ObservableList<Person> and an unmodifiable ObservableList<Transaction> that can be 'observed' e.g. the UI can be bound to these lists so that the UI automatically updates when the data in the respective lists change.
does not depend on any of the other three components.

The Wallet,

consists of a BudgetList.
consists of a TransactionList, which contains Income(s) and a TransactionList which contains Expense(s).

The AddressBook,

consists of a UniquePersonList.

The UserData,

consists of a User.

The Model package consists of four main packages: Person, Transaction, Reminder and Tag.

Figure 7. In-depth structure of Person package in the Model Component

The diagram above shows how the Person package is implemented:

PeoplePredicate: PeopleNamePredicate, PeoplePhonePredicate, PeopleTagPredicate, PeopleEmailPredicate are implemented for the execution of people find command.
A User consists of a Name, a Phone and an Email.
A Person consists of a Name, a Phone, an Email, a TransactionList of Debt(s), a TransactionList of Loan(s) and a set of Tag(s).

Figure 8. In-depth structure of Transaction package in the Model Component

Figure 9. Transaction class diagram

The association between Transaction and Amount is not shown in In-depth structure of Transaction package in the Model Component to keep the diagram less messy. However, the association is shown in Transaction class diagram.

The diagram above shows how the Transaction package is implemented:

WalletPredicate: DateContainsKeywordsPredicate, DescriptionContainsKeywordsPredicate, TagContainsKeywordsPredicate, AmountContainsKeywordsPredicate are implemented for the execution of wallet find command.
The abstract class Transaction is extended by Income, Expense, Debt and Loan. A Transaction consists of a Description, an Amount, a Date and a Tag.
A Budget consists of a Year, a Month and an Amount.

Figure 10. Reminder class diagram

The Reminder package is implemented for Sharkie's reminder feature. The diagram above shows how the Reminder package is implemented:

The Reminder consists of a User (the sender) and a Person (the receiver).
- A Reminder object is created whenever the people remind or people remindall command is executed.
The ConfirmationEmail consists of a User.
- The ConfirmationEmail is implemented to validate the user’s email address during user’s first login to Sharkie.

The Tag package only consist of a class, Tag and it does not depend on other components in the Model.

Implementation

People Received Command

The people received command is implemented in the class, PeopleReceivedCommand.

This command can be accessed from Logic#execute(). It deletes the Loan(s) of the indicated Person (the Person with the specified index in the Address Book).

The following activity diagram illustrates what happens when the user executes a people received command:

Figure 11. Activity diagram of recording the amount of money received

Implementation of `people received` command

In PeopleReceivedCommand class, the list of Persons is obtained from the Model via Model#getFilteredPersonList() and the indicated person is extracted from the list.
The list of Loans of the Person is extracted and modified based on the command entered by the user.
A new Person with the modified list of Loans is created.
This new Person replace the initial Person at the indicated index via Model#setPerson() and the filteredPersons in the Model is updated.

The following sequence diagram summarizes what happens during the execution of a people received command:

Figure 12. Sequence diagram of the people received command

The lifeline for PeopleReceivedCommand and PeopleReceivedCommandParser should end at the destroy marker (X) but due to a limitation of PlantUML, the lifeline reaches the end of diagram.

Design Considerations

Aspect: Deletion of `Loan` from the indicated person.

Alternative 1 (current choice): Creates a new Person with the modified list of Loans and use Model#setPerson() to replace the indicated Person with the new Person created.
- Pros: Preserve the immutable property of Person.
- Cons: Have to copy over all the attribute values, such as Name, Phone and more.
Alternative 2: Modify the list of Loans in the indicated Person directly.
- Pros: Easier and can save time from copying the information from one Person to another.
- Cons: Person loses the immutable property.

Appendix C: Use Cases

Wallet Tab

(For all use cases below, the System is the Wallet and the Actor is the User, unless specified otherwise)

Use case: UC1 - Recording an expense

MSS

User requests to add an expense into the wallet.
Wallet adds the expense and displays the expense in the list of expenses.

Use case ends.

Extensions

1a. The amount keyed in by the user is invalid.
- 1a1. Wallet shows an error message.
- 1a2. User re-enters the expense.
  
  Steps 1a1-1a2 are repeated until the amount keyed in by the user is correct.
  
  Use case resumes at step 2.

Use case: UC2 - Recording an income

MSS

User requests to add an income into the wallet.
Wallet adds the income and displays the income in the list of incomes.

Use case ends.

Extensions

1a. The amount keyed in by the user is invalid.

Steps 1a1-1a2 of recording an expense (UC1) are repeated until the amount keyed in by the user is valid.

Use case resumes at step 2.

Use case: UC3 - Setting budget

MSS

User requests to set a budget.
Wallet sets the amount keyed in as the budget of the month indicated.

Use case ends.

Extensions

1a. The amount keyed in by the user is invalid.

Steps 1a1-1a2 of recording an expense (UC1) are repeated until the amount keyed in by the user is valid.

Use case resumes at step 2.
1b. The amount keyed in by the user has no date attached to it.
- 1b1. Wallet automatically assigns the budget entered as the default budget of each month.
  
  Use case ends.

Use case: UC4 - Deleting a transaction

Preconditions: The transaction that the user wants to delete exists in the wallet.

MSS

User requests to delete a specific transaction in the wallet.
Wallet deletes the transaction and displays the list of remaining transactions.

Use case ends.

Extensions

1a. The transaction’s index keyed in by the user is invalid.
- 1a1. Wallet shows an error message.
- 1a2. User re-enters the index.
  
  Steps 1a1-1a2 are repeated until the index keyed in is valid.
  
  Use case resumes at step 2.

Use case: UC5 - Editing a transaction

Preconditions: The transaction that the user wants to edit exists in the wallet.

MSS

User requests to edit a specific transaction in the wallet.
Wallet edits the transaction and shows the list with the edited transaction.

Use case ends.

Extensions

1a. The transaction’s index keyed in by the is invalid.

Steps 1a1-1a2 of deleting an transaction (UC4) are repeated until the index keyed in by the user is valid.

Use case resumes at step 2.

1b. The user did not indicate the field to edit.
- 1b1. Wallet shows an error message.
- 1b2. User re-enters the edit command.
  
  Steps 1b1-1b2 are repeated until the edit command keyed in is valid.
  
  Use case resumes at step 2.

Use case: UC6 - Finding a transaction

MSS

User keys in a keyword.
Wallet lists out the transactions that contain the keyword.

Use case ends.

Extensions

1a. The keyword entered by the user does not exist in the wallet.
- 1a1. Wallet shows an empty list.
  
  Use case ends.

Use case: UC7 - Listing all transactions

MSS

User enters the list command.
Wallet lists out all the transactions.

Use case ends.

People Tab

(For all use cases below, the System is the Address Book and the Actor is the User, unless specified otherwise)

Use case: UC8 - Adding a person

MSS

User requests to add a person into the address book.
Address book adds the person and displays the person in the list of people.

Use case ends.

Extensions

1a. The person’s details keyed in by the user is invalid.
- 1a1. Address book shows an error message.
- 1a2. User re-enters the person’s details.
  
  Steps 1a1-1a2 are repeated until the details keyed in is correct.
  
  Use case resumes at step 2.

Use case: UC9 - Sending reminder to a friend

MSS

User requests to send a reminder to a friend.
Address book sends a reminder to the friend.

Use case ends.

Extensions

1a. The person’s index keyed in by the user is invalid.
- 1a1. Address book shows an error message.
- 1a2. User re-enters the index.
  
  Steps 1a1-1a2 are repeated until the index keyed in is valid.
  
  Use case resumes at step 2.

1b. Address book shows that the friend does not owe the user money.

Use case ends.

Use case: UC10 - Recording the money the user owes

Preconditions: The friend, who user owes exists in the address book.

MSS

User enters the amount borrowed from a friend.
Address book records the amount, which the user owes the friend.

Use case ends.

Extensions

1a. The person’s index keyed in by the user is invalid.

Steps 1a1-1a2 of sending reminder to a friend (UC9) are repeated until index keyed in by the user is valid.

Use case resumes at step 2.

1b. The amount keyed in by the user is invalid.
- 1b1. Address book shows an error message.
- 1b2. User re-enters the amount.
  
  Steps 1b1-1b2 are repeated until the amount keyed in is correct.
  
  Use case resumes at step 2.

Use case: UC11 - Recording the money the user lends

Preconditions: The friend, who user lends exists in the address book.

MSS

User enters the amount lent to a friend.
Address book records the amount, which the user lends to the friend.

Use case ends.

Extensions

1a. The person’s index keyed in by the user is invalid.

Steps 1a1-1a2 of sending reminder to a friend (UC9) are repeated until the index keyed in by the user is valid.

Use case resumes at step 2.

1b. The amount keyed in by the user is invalid.

Steps 1b1-1b2 of recording the money the user owes (UC10) are repeated until the amount keyed in by the user is valid.

Use case resumes at step 2.

Use case: UC12 - Deleting a person

Preconditions: The person, who user wants to delete exists in the address book.

MSS

User requests to delete a specific person in the address book.
Address book deletes the person and shows the list of the remaining people.

Use case ends.

Extensions

1a. The person’s index keyed in by the user is invalid.

Steps 1a1-1a2 of sending reminder to a friend (UC9) are repeated until the index keyed in by the user is valid.

Use case resumes at step 2.

Use case: UC13 - Editing a person

Preconditions: The person, who user wants to edit exists in the address book.

MSS

User requests to edit a specific person in the address book.
Address book updates the indicated person’s detail and show the list of people with the edited person.

Use case ends.

Extensions

1a. The person’s index keyed in by the user is invalid.

Steps 1a1-1a2 of sending reminder to a friend (UC9) are repeated until the index keyed in by the user is valid.

Use case resumes at step 2.

1b. The person’s new details keyed in by the user is invalid.

Steps 1a1-1a2 of adding a person (UC8) are repeated until the details keyed in by the user is valid.

Use case resumes at step 2.

Use case: UC14 - Finding a person

MSS

User keys in a keyword.
Address book lists out the people, who contain the keyword in their names.

Use case ends.

Extensions

1a. The keyword entered by the user does not exist in the address book.
- 1a1. Address book shows an empty list.
  
  Use case ends.

Appendix G: Instructions for Manual Testing

Recording the flow of money

Recording the money you lend to a person
1. Prerequisites: The person whom you lend to exists in the person list.
2. Test case: people lend 1 n/Dinner $/12.00
  Expected: A loan named Dinner with $12.00 is added into the loan list of the first person.
3. Test case: people lend 1 n/Dinner $/12.00 d/02/02/2020
  Expected: A loan named Dinner with $12.00, recorded under the date 02/02/2020 is added into the loan list of the first person. Total amount of money, which you lent to the first person is shown in the result display.
4. Test case: people lend 0 n/Dinner $/12.00
  Expected: The loan is not recorded. Error details shown in the result display.
5. Other invalid people lend commands to try:
  - people lend,
  - people lend 1,
  - people lend 1 n/Chicken Rice,
  - people lend 1 $/12.00,
  - people lend n/Chicken Rice $/12.00,
  - people lend x n/Dinner $/12.00 (where x is larger than the person list size),
  - people lend x n/Dinner $/12.00 (where x is a negative number),
  - people lend x n/Dinner $/12.00 (where x is a non-integer),
  - people lend 1 n/Dinner $/x (where x is a negative number),
  - people lend 1 n/Dinner $/x (where x is greater 92233720368547758.07),
  - people lend 1 n/Dinner $/x (where x has more than 2 decimal places) or
  - people lend 1 n/Dinner $/x (where x is not a number).
    Expected: Similar to previous
Recording the money you received from a person
1. Prerequisites: The person whom you received from exists in the person list.
2. Test case: people received 1 i/1
  Expected: The first loan of the first person is deleted from the loan list. Remaining amount of loan, which have yet settled by the first person is shown in the result display.
3. Test case: people received 0 i/1
  Expected: No loan is deleted. Error details shown in the result display.
4. Other invalid people received commands to try:
  - people received,
  - people received 1,
  - people received i/1,
  - people received x i/1 (where x is larger than the person list size),
  - people received x i/1 (where x is a negative number),
  - people received x i/1 (where x is a non-integer value),
  - people received 1 i/x (where x is larger than the loan list size),
  - people received 1 i/x (where x is a negative number or zero) or
  - people received 1 i/x (where x is a non-integer value)
    Expected: Similar to previous

Sending reminders

Reminding a specific person about the unsettled loan(s).
1. Prerequisites: Connected to the Internet. Your firewall or antivirus programme (if any) allows the connection to STMP port 587. The person who you want to remind exists in the person list. The person has at least one loan in the loan list. The email of the person to be reminded is a valid email (You can generate an email from temp-mail.org).
2. Test case: people remind 1
  Expected: A reminder is sent to the first person’s email. A carbon copy (CC) of the reminder is sent to you. A success message shown in the result display.
3. Test case: people remind 0
  Expected: No reminder is sent. Error details shown in the result display.
4. Other invalid people remind commands to try:
  - people remind,
  - people remind x (where x is larger than the person list size),
  - people remind x (where x is a negative number) or
  - people remind x (where x is a non-integer value)
    Expected: Similar to previous
Reminding all people about the unsettled loan(s).
1. Prerequisites: Connected to the Internet. Your firewall or antivirus programme (if any) allows the connection to STMP port 587. At least one person in the list has at least one loan. The email(s) of the people to be reminded are valid email(s) (You can generate an email from temp-mail.org).
2. Test case: people remindall
  Expected: A reminder is sent everyone, who has unsettled loan. A carbon copy (CC) of each of the reminder is sent to you. A list of people reminded is shown in the result display, along with the success message.