[updateD command] inconsistent error message

[NiniJiaying]

Issue description

While there are only 20 deadlines in the list, providing index 33 and index 0 (both are invalid index) will return different error messages.

Steps to reproduce the issue

1. type "updateD 1 i/33"
2. type "updateD 1 i/0"

What's the expected result?

• the error messages are expected to be the same

What's the actual result?

• different error messages are shown. "The deadline index provided is invalid." for "updateD 1 i/0" while "At least one field to update must be provided." for "updateD 1 i/33"

[nus-pe-bot]

Team's Response

This is the expected behaviour of the application.

For both cases, there are two errors present.

1. Index is invalid
2. Command format is invalid since at least one field to update must be provided.

In this case, because of the way CoLAB checks for errors, the error messages are given in a different order as shown in the testers screenshots. However, once one of the issues is addressed, the other error message will appear.

For example, following the example given, the user types updateD 1 i/33 and gets the error mentioned At least one field to update must be provided.

The user now corrects the command format by providing a field to be updated. e.g. updateD 1 i/33 d/Updated Description. CoLAB now let's the user know that the deadline index provided is incorrect.

Similarly, for updateD 1 i/0, if you were to correct the invalid index you would get the message saying that the command format is invalid.

This issue should be rejected because in either case the user is informed of the two errors, only in a different order which shouldn't matter to the user.

Items for the Tester to Verify

:question: Issue response

Team chose [response.Rejected]

• [x] I disagree

Reason for disagreement: The team should not expect that the user's understanding of "invalid" is exactly the same as theirs. In this case, a better way is to specify what kind of index is invalid. To me, an index out of scope (larger than the number of tasks in the list) is an invalid index. Hence, the system should not proceed the user to enter more information as this command is already invalid. No user would be happy if they listen to the error message and modified their input but still gets nothing since their first wrong input is not correctly notified.

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:question: Issue severity

Team chose [severity.VeryLow] Originally [severity.Medium]

• [x] I disagree

Reason for disagreement: If the ultimate error message is "The deadline index provided is invalid", the system is responsible to notify the user of this error as early as possible.

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