Fix mock set resolution for folder-based organization

[Copilot]

Mock sets were not resolving when organized by folder structure (e.g., parameter/get___set1.json). Two bugs in lib/mock.js:

Path parsing used wrong separator

• Line 68 used path.delimiter (: or ; for PATH env var) instead of path.sep (/ or \)
• Prevented folder components from being extracted

Set name regex captured leading underscores

• Pattern /__(\w-]+?)$/ matched \w which includes _
• For get___set1.json: matched ___set1, captured _set1 (wrong), left basename as get (missing trailing _)
• Changed to /__([a-z\d][\w-]*)$/i to require first char after __ be alphanumeric
• For get___set1.json: now matches __set1, captures set1, leaves basename as get_ (correct)

Users can now organize mocks:

parameter/
  get_.json         # default
  get___set1.json   # --set set1
  get___set2.json   # --set set2

Where get_ is the method prefix, folder provides the path, and __setname is the set suffix.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Mock sets don’t resolve when organizing by folder structure</issue_title>
<issue_description>Hi smoke maintainers,

We’re using mock sets to simulate different user roles. The documented filename suffix approach works as expected, e.g.:

get_parameter__set1.json

get_parameter__set2.json

According to the documentation, mock sets are selected via the __set-name suffix and smoke --set name.

What we tried:

For a clearer structure, we wanted to group mocks by “parameter” using folders and keep only the set name in the filename:

parameter/
  get___set1.json
  get___set2.json
  get___set3.json

Note: we tried it with 2 and 3 underscores, both don't work

Expected behavior

Smoke resolves these the same way as the flat structure (i.e., folder name doesn’t interfere with set selection), or there’s a supported convention for “set folders”.

Actual behavior

This does not work properly (the mocks are not selected / resolved as expected when running with --set set1, etc.), only the default get_.json file is used.

Question

Is this intended behavior (mock sets only supported via filename suffix), or is this a bug / missing feature?

Thanks a lot!

Felix
</issue_description>

Comments on the Issue (you are @copilot in this section)

@sinedied Sounds like a bug, thanks for the report

• Fixes Mock sets don’t resolve when organizing by folder structure #38

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