index out of range runtime error in slash_dmy.go

[cpalsulich]

The getDays method attempts to access array elements using a passed in month argument as an index. The problem is month can be larger than 12 because the regex defined in SlashDMY matches on dates in a mm/dd/yyyy format. So this means a date like 1/30/2023 will cause a panic.

[cpalsulich]

Relevant stack trace lines:

runtime error: index out of range [21] with length 13
  /go/pkg/mod/github.com/olebedev/when@v0.0.0-20221205223600-4d190b02b8d8/rules/common/slash_dmy.go:32
  /go/pkg/mod/github.com/olebedev/when@v0.0.0-20221205223600-4d190b02b8d8/rules/rules.go:42

[olebedev]

Hello @cpalsulich, thank you for your report. There are two separate issues with the library:

1. The library is currently causing panics, which is an unexpected behavior. We have to treat this as a bug or missing feature and resolve it accordingly. Pull requests are welcome!

2. Regarding the parsing of the US date standard (mm/dd/yyyy) using the default set of rules defined in this line, it is unclear whether this is a bug or intended behavior. The rule implemented in slash_dmy.go is specifically designed to parse the dd/mm/yyyy format indicated by its file name. Therefore, expecting successful parsing of the mm/dd/yyyy format is not appropriate in this case.

To resolve this issue, you will need to create a custom rule that handles the desired date format. Pull requests are very welcome, as always!

Hope that helps,
Oleg

[olebedev]

Related #10

[olebedev]

Related #19

[olebedev]

Resolved in #37