"LGTM" tool warns about regexp for "remove_internal_links" function (for PDF build)

[DimitriPapadopoulos]

Here are the two LGTM warnings:

• https://lgtm.com/projects/g/bids-standard/bids-specification/snapshot/225bf2292f8dc5754a4829c837074b91ad9d9980/files/pdf_build_src/process_markdowns.py?sort=name&dir=ASC&mode=heatmap#x48aac9687c9e224f:1
• https://lgtm.com/projects/g/bids-standard/bids-specification/snapshot/225bf2292f8dc5754a4829c837074b91ad9d9980/files/pdf_build_src/process_markdowns.py?sort=name&dir=ASC&mode=heatmap#x6ea466000e63cf12:1

The relevant lines of code:

• line 114 of pdf_build_src/process_markdowns.py

        primary_pattern = re.compile(r'\[((?!http).[\w\s.\(\)`*/–]+)\]\(((?!http).+(\.md|\.yml|\.md#[\w\-\w]+))\)')  # noqa: E501

• line 117 of pdf_build_src/process_markdowns.py

        primary_pattern = re.compile(r'\[([\w\s.\(\)`*/–]+)\]\(([#\w\-._\w]+)\)')

Indeed, there are two \w within classes of characters delimited by [] and not groups of characters delimited by ():

• [\w\-\w]
• [#\w\-._\w]

See Duplication in regular expression character class:

Character classes in regular expressions represent sets of characters, so there is no need to specify the same character twice in one character class. Duplicate characters in character classes are at best useless, and may even indicate a latent bug.

Recommendation

Determine whether a character is simply duplicated or whether the character class was in fact meant as a group. If it is just a duplicate, then remove the duplicate character. If was supposed to be a group, then replace the square brackets with parentheses.

[sappelhoff]

as mentioned in #855 (review), this should probably be fixed as part of #596