Wrong error message when duplicate arguments

[nus-pe-bot]

If the user duplicates the argument by in deadline command, the following error message show up:

however, the error message said the time format was invalid while the user entered the correct formats. The error message should be about the duplicate arguments

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_{[original: nus-cs2113-AY2425S1/pe-interim#549] [original labels: type.DocumentationBug severity.VeryLow]}

[NCF3535]

Team's Response

Thank you for the bug report. We appreciate your effort in identifying this issue and highlighting the mismatch in error messaging.

Issue Explanation:

• The command deadline Have medicine /by 19:00 /by 12:00 /tag dsafsaf fails because the /by flag is duplicated. However, the error message displayed incorrectly points to the time format as the source of the error instead of highlighting the duplicate /by flags.
• This can understandably cause confusion, as the error message does not reflect the actual issue, which is the presence of multiple /by flags.

Why This Happens:

• The program does not currently check for or handle duplicate flags like /by. As a result:
  • The input 19:00 /by 12:00 is processed sequentially by the date-time validator.
  • The validator interprets the second /by flag as part of the time value, resulting in an invalid time format.
• However, the DateTime validation correctly rejects the invalid input based on its rules, as 19:00 /by 12:00 is not a valid time format. While this behaviour is correct from the perspective of the DateTime validator, the root cause of the issue (duplicate /by flags) is not explicitly identified.

Justification for NotInScope:

• Addressing this issue would require substantial changes to the command parsing and validation logic. Specifically:
  • The parser would need to be updated to detect and report duplicate flags (like /by) during the command parsing stage, before passing arguments to the DateTime validator. This would require restructuring the sequence of validations and introducing additional checks to ensure correctness.
  • Adding these checks increases the complexity of the parsing logic and introduces the potential for regressions in other areas, particularly when processing similar flags (e.g., /tag or other command-specific options).
• The app currently works as intended and ensures invalid commands do not proceed. While the intermediate error message may not identify the root cause, the app still prevents errors and informs the user that the command is invalid through the final output ("Invalid Task Command").
• Since fixing this issue involves changes that are non-trivial and the app's behaviour aligns with the User Guide, this issue is categorised as NotInScope for the current version.

Proposed Enhancement:

• In future iterations, we may consider refining the command parsing logic to detect and handle duplicate flags. This enhancement would allow the app to produce more precise error messages, such as:
  "Duplicate flag detected: /by. Please ensure each flag is used only once in the command."

Conclusion: While the app functions as documented and this issue does not impact its usability, we acknowledge that the error message could be improved to reduce user confusion. We appreciate your feedback and will consider this enhancement in future updates to further refine error reporting and the overall user experience.

Thank you again for bringing this to our attention.

Duplicate status (if any):

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