lint(track_config): check status-dependent exercise rules

[ee7]

With this commit, configlet lint now checks that a track-level
config.json file follows the below rules for Concept Exercises:

• The exercises.concept[].concepts value must be a non-empty array of
  strings if exercises.concept[].status is not equal to deprecated
• The exercises.concept[].concepts value must be an empty array if
  exercises.concept[].status is equal to deprecated
• The exercises.concept[].prerequisites value must be a non-empty
  array of strings if exercises.concept[].status is not equal to
  deprecated, except for exactly one exercise which is allowed to have
  an empty array as its value
• The exercises.concept[].prerequisites value must be an empty array
  if exercises.concept[].status is equal to deprecated

and these rules for Practice Exercises:

• The exercises.practice[].practices value must be an empty array if
  exercises.practice[].status is equal to deprecated
• The exercises.practice[].prerequisites value must be an empty array
  if exercises.practice[].status is equal to deprecated
• The exercises.practice[].prerequisites value must be an empty array
  if exercises.practice[].slug is equal to hello-world

This commit also adds support for the below checks of
Practice Exercises. However, because there would currently be too many
linting errors, this commit leaves these checks disabled for now:

• The exercises.practice[].practices value must be a non-empty array
  of strings if exercises.practice[].status is not equal to
  deprecated
• The exercises.practice[].prerequisites value must be a non-empty
  array of strings if exercises.practice[].status is not equal to
  deprecated

Closes: #386

---

This PR currently includes the commit from #414. We will merge that one PR first, then rebase this PR on top. Edit: done.

At the time of writing (2021-09-06T18:27:00Z), this PR causes the below diff to the output of configlet lint, per track:

elixir

https://github.com/exercism/elixir/blob/d5f3834445ca/config.json#L1153-L1338

+The Practice Exercise `binary` has a `status` of `deprecated`, but has a non-empty array of `practices`:
+./config.json
+
+The Practice Exercise `binary` has a `status` of `deprecated`, but has a non-empty array of `prerequisites`:
+./config.json
+
+The Practice Exercise `hexadecimal` has a `status` of `deprecated`, but has a non-empty array of `practices`:
+./config.json
+
+The Practice Exercise `hexadecimal` has a `status` of `deprecated`, but has a non-empty array of `prerequisites`:
+./config.json
+
+Configlet detected at least one problem.
+For more information on resolving the problems, please see the documentation:
+https://github.com/exercism/docs/blob/main/building/configlet/lint.md

python

https://github.com/exercism/python/blob/6afbd74d3bce/config.json#L1971-L2190

+The Practice Exercise `accumulate` has a `status` of `deprecated`, but has a non-empty array of `prerequisites`:
+./config.json
+
+The Practice Exercise `binary` has a `status` of `deprecated`, but has a non-empty array of `prerequisites`:
+./config.json
+
+The Practice Exercise `error-handling` has a `status` of `deprecated`, but has a non-empty array of `prerequisites`:
+./config.json
+
+The Practice Exercise `hexadecimal` has a `status` of `deprecated`, but has a non-empty array of `prerequisites`:
+./config.json
+
+The Practice Exercise `nucleotide-count` has a `status` of `deprecated`, but has a non-empty array of `prerequisites`:
+./config.json
+
+The Practice Exercise `octal` has a `status` of `deprecated`, but has a non-empty array of `prerequisites`:
+./config.json
+
+The Practice Exercise `parallel-letter-frequency` has a `status` of `deprecated`, but has a non-empty array of `prerequisites`:
+./config.json
+
+The Practice Exercise `pascals-triangle` has a `status` of `deprecated`, but has a non-empty array of `prerequisites`:
+./config.json
+
+The Practice Exercise `point-mutations` has a `status` of `deprecated`, but has a non-empty array of `prerequisites`:
+./config.json
+
+The Practice Exercise `proverb` has a `status` of `deprecated`, but has a non-empty array of `prerequisites`:
+./config.json
+
+The Practice Exercise `strain` has a `status` of `deprecated`, but has a non-empty array of `prerequisites`:
+./config.json
+
+The Practice Exercise `trinary` has a `status` of `deprecated`, but has a non-empty array of `prerequisites`:
+./config.json
+
+Configlet detected at least one problem.
+For more information on resolving the problems, please see the documentation:
+https://github.com/exercism/docs/blob/main/building/configlet/lint.md

zig

https://github.com/exercism/zig/blob/3d166c4e2a7a/config.json#L21-L36

+The Practice Exercise `hello-world` is user-facing (because a missing `status` key implies `active`), but has a non-empty array of `prerequisites`:
+./config.json
+

[BethanyG]

@ee7 -- Since I am here and in cleanup mode anyways, I'll PR a fix for the ones you found for Python. 😄 And..many thanks for adding these checks into configlet!

[ee7]

I'll PR a fix for the ones you found for Python

Great, thanks.

I've created the PRs for elixir and zig. So here are the relevant PRs:

• Remove prerequisites from deprecated Practice Exercises elixir#889
• Remove practices from deprecated Practice Exercises elixir#890
• Removed prerequisite listings from depricated exercises. python#2562
• Remove prerequisites from hello-world zig#84

[ErikSchierboom]

Thanks for working on this. I've left a minor nit.

[ErikSchierboom]

What is PCP? To me this is a non-intuitive abbreviation so I'd prefer it being spelled out a bit more.

[ee7]

What is PCP?

Indeed. I'll try to improve it.

("practices, concepts, prerequisites")

[ee7]

I don't think I've found a great factoring here yet - in particular I don't like the proc names.

For the first pass we have a proc called hasValidExercises, and for the second pass:

• checkExerciseConcepts ("why do we need this when hasValidExercises returned true?")
• checkExercisePrerequisites
• checkExercisePCP (the non-obvious "practices, concepts, prerequisites")

Where we will extend/add procs for the second pass to add the remaining exercises.concept[] and exercises.practice[] rules, like:

• The "exercises.concept[].slug" value must be unique in "exercises.concept[].slug" and may not exist in "exercises.practice[].slug"
• The "exercises.practice[].slug" value must be unique in "exercises.practice[].slug" and may not exist in "exercises.concept[].slug"
• There must be exactly one "exercises.practice[].slug" value that is the string hello-world
• The "exercises.practice[].practices" values must match the "concepts[].slug" property of one of the concepts
• The "exercises.practice[].practices" values must refer to an individual concept's slug at most 10 times (across all exercises)
• The "exercises.practice[].prerequisites" values must match any concept exercise's "exercises.concept[].concepts" values
• The "exercises.practice[].prerequisites" values must match the "concepts[].slug" property of one of the concepts
• The "concepts" value must have a entry with a matching "slug" property for each concept listed in a concept exercise's "concepts" property

So the names might need to change later too. But I'll try to improve the current situation a little.

[ErikSchierboom]

👍 I'm fine with renaming later BTW.