configlet lint


The primary use of configlet is linting: checking if a track's configuration files are properly structured - both syntactically and semantically. Misconfigured tracks may not sync correctly, may look wrong on the website, or may present a suboptimal user experience, so configlet's guards play an important part in maintaining the integrity of Exercism.

Usage

The lint command can be used to lint a track.

configlet [global-options] lint [command-options]

Global options:
  -h, --help                   Show this help message and exit
      --version                Show this tool's version information and exit
  -t, --track-dir <dir>        Specify a track directory to use instead of the current directory
  -v, --verbosity <verbosity>  The verbosity of output. Allowed values: q[uiet], n[ormal], d[etailed]

Rules

These are the linting rules being checked.

Rule: required files are present

The linter should check if all the required files are present. The non-exercise specific files that must be present are:

  • config.json
  • docs/ABOUT.md
  • docs/INSTALLATION.md
  • docs/LEARNING.md
  • docs/RESOURCES.md
  • docs/SNIPPET.txt
  • docs/TESTS.md
  • exercises/shared/.docs/help.md
  • exercises/shared/.docs/tests.md

The Concept Exercise specific files that must be present are:

  • exercises/concept/<slug>/.docs/hints.md
  • exercises/concept/<slug>/.docs/instructions.md
  • exercises/concept/<slug>/.docs/introduction.md
  • exercises/concept/<slug>/.meta/config.json

There will be a similar list for Practice Exercises, but we've not yet defined the spec for that.

Each concept listed in the config.json should have the following files:

  • concepts/<slug>/about.md
  • concepts/<slug>/introduction.md
  • concepts/<slug>/links.json

Rule: config.json file is valid

The config.json file should have the following checks:

  • The file must be valid JSON
  • The "language" key is required
  • The "language" value must be a non-blank stringĀ¹ with length <= 255
  • The "slug" key is required
  • The "slug" value must be a kebab-case stringĀ² with length <= 255
  • The "active" key is required
  • The "active" value must be a boolean
  • The "blurb" key is required
  • The "blurb" value must be a non-blank stringĀ¹ with length <= 400
  • The "version" key is required
  • The "version" value must be the integer 3
  • The "status.concept_exercises" key is required
  • The "status.concept_exercises" value must be a boolean
  • The "status.test_runner" key is required
  • The "status.test_runner" value must be a boolean
  • The "status.representer" key is required
  • The "status.representer" value must be a boolean
  • The "status.analyzer" key is required
  • The "status.analyzer" value must be a boolean
  • The "online_editor.indent_style" key is required
  • The "online_editor.indent_style" value must be the string space or tab
  • The "online_editor.indent_size" key is required
  • The "online_editor.indent_size" value must be an integer >= 0 and <= 8
  • The "online_editor.highlightjs_language" key is required
  • The "online_editor.highlightjs_language" value must be a non-blank stringĀ¹
  • The "files" key is optional
  • The "files" value must be an object
  • The "files.solution" key is optional
  • The "files.solution" value must be an array
  • The "files.solution" values must be valid patternsāµ
  • The "files.solution" values must not have duplicates
  • The "files.test" key is optional
  • The "files.test" value must be an array
  • The "files.test" values must be valid patternsāµ
  • The "files.test" values must not have duplicates
  • The "files.example" key is optional
  • The "files.example" value must be an array
  • The "files.example" values must be valid patternsāµ
  • The "files.example" values must not have duplicates
  • The "files.exemplar" key is optional
  • The "files.exemplar" value must be an array
  • The "files.exemplar" values must be valid patternsāµ
  • The "files.exemplar" values must not have duplicates
  • The "files.editor" key is optional
  • The "files.editor" value must be an array
  • The "files.editor" values must be valid patternsāµ
  • The "files.editor" values must not have duplicates
  • The "files.invalidator" key is optional
  • The "files.invalidator" value must be an array
  • The "files.invalidator" values must be valid patternsāµ
  • The "files.invalidator" values must not have duplicates
  • Patterns can only be listed in either the "files.solution", "files.test", "files.example", "files.exemplar", "files.editor" or "files.invalidator" array (no overlap)
    • If the track is d or plsql, the "files.solution" and "files.test" files can overlap
    • The "files.example and "files.exemplar" files can overlap
  • The "test_runner.average_run_time" key is required if "status.test_runner" is equal to true
  • The "test_runner.average_run_time" value must be a floating-point number > 0 with one decimal point of precision
  • The "approaches.snippet_extension" key is required if the track has one or more approaches
  • The "approaches.snippet_extension" value must be a non-blank stringĀ¹
  • The "exercises" key is required
  • The "exercises.concept" key is required
  • The "exercises.concept" value must be an array
  • The "exercises.concept[].slug" key is required
  • The "exercises.concept[].slug" value must be a kebab-case stringĀ² with length <= 255
  • The "exercises.concept[].slug" value must be unique in "exercises.concept[].slug" and may not exist in "exercises.practice[].slug"
  • The "exercises.concept[].name" key is required
  • The "exercises.concept[].name" value must be a Title Case stringĀ³ with length <= 255
  • The "exercises.concept[].uuid" key is required
  • The "exercises.concept[].uuid" value must be a unique version 4 UUID stringā¶
  • The "exercises.concept[].uuid" value for each exercise must never change
  • The "exercises.concept[].concepts" key is required
  • 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[].concepts" values must be kebab-case stringsĀ²
  • The "exercises.concept[].concepts" values must not have duplicates
  • The "exercises.concept[].concepts" values must not be in any other concept exercise's "concepts" property
  • The "exercises.concept[].concepts" values must match the "concepts.slug" property of one of the concepts
  • The "exercises.concept[].prerequisites" key is required
  • 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
  • The "exercises.concept[].prerequisites" values must be kebab-case stringsĀ²
  • The "exercises.concept[].prerequisites" values must not have duplicates
  • The "exercises.concept[].prerequisites" values must match any other concept exercise's "concepts" property values
  • The "exercises.concept[].prerequisites" values must not match any of the values in the exercise's "exercises.concept[].concepts" property
  • The "exercises.concept[].prerequisites" values must match the "concepts.slug" property of one of the concepts
  • There must not be any cycles between "exercises.concept[].concepts" and "exercises.concept[].prerequisites"
  • The "exercises.concept[].status" key is optional
  • The "exercises.concept[].status" value must be the string wip, beta, active or deprecated
  • The "exercises.practice" key is required
  • The "exercises.practice" value must be an array
  • The "exercises.practice[].slug" key is required
  • The "exercises.practice[].slug" value must be a kebab-case stringĀ² with length <= 255
  • 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[].name" key is required
  • The "exercises.practice[].name" value must be a Title Case stringĀ³ with length <= 255
  • The "exercises.practice[].uuid" key is required
  • The "exercises.practice[].uuid" value must be a unique version 4 UUID stringā¶
  • The "exercises.practice[].uuid" value for each exercise must never change
  • The "exercises.practice[].difficulty" key is required
  • The "exercises.practice[].difficulty" value must be an integer >= 1 and <= 10
  • The "exercises.practice[].practices" key is required
  • 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[].practices" value must be an empty array if "exercises.practice[].status" is equal to deprecated
  • The "exercises.practice[].practices" values must be kebab-case stringsĀ²
  • The "exercises.practice[].practices" values must not have duplicates
  • 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" key is required
  • The "exercises.practice[].prerequisites" 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 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
  • The "exercises.practice[].prerequisites" values must be kebab-case stringsĀ²
  • The "exercises.practice[].prerequisites" values must not have duplicates
  • 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 "exercises.practice[].status" key is optional
  • The "exercises.practice[].status" value must be the string wip, beta, active or deprecated
  • The "exercises.practice[].status" value must, if "exercises.practice[].slug" is equal to hello-world, be either omitted or the string active
  • The "exercises.foregone" key is optional
  • The "exercises.foregone" value must be an array
  • The "exercises.foregone" values must be kebab-case stringsĀ²
  • The "exercises.foregone" values must not have duplicates
  • The "exercises.foregone" values must not match any of the concept or practice exercise slugs
  • The "concepts" key is required
  • The "concepts" value must be an array
  • The "concepts[].uuid" key is required
  • The "concepts[].uuid" value must be a unique version 4 UUID stringā¶
  • The "concepts[].uuid" value for each concept must never change
  • The "concepts[].slug" key is required
  • The "concepts[].slug" value must be a kebab-case stringĀ² with length <= 255
  • The "concepts[].name" key is required
  • The "concepts[].name" value must be a Title Case stringĀ³ with length <= 255
  • Each "concepts" value must have a concept/<concepts.slug>/about.md file. Linting rules for this file are specified below.
  • Each "concepts" value must have a concept/<concepts.slug>/introduction.md file. Linting rules for this file are specified below.
  • Each "concepts" value must have a concept/<concepts.slug>/links.json file. Linting rules for this file are specified below.
  • The "key_features" key is optional
  • The "key_features" value must be an array with length = 6
  • The "key_features[].icon" key is required
  • The "key_features[].icon" value must use one of the pre-defined icon values
  • The "key_features[].title" key is required
  • The "key_features[].title" value must be a Sentence Case stringā“ with length <= 25
  • The "key_features[].content" key is required
  • The "key_features[].content" value must be a non-blank stringĀ¹ with length <= 100
  • The "tags" key is required
  • The "tags" value must be an array of strings
  • The "tags" values must not have duplicates
  • The "tags" values must use one of the pre-defined tag values

Rule: exercises/concept/<slug>/.meta/config.json is valid

  • The file must be valid JSON
  • The JSON root must be an object
  • The "blurb" key is required
  • The "blurb" value must be a non-blank stringĀ¹ with length <= 350
  • The "source" key is optional
  • The "source" value must be a non-blank stringĀ¹
  • The "source_url" key is optional
  • The "source_url" value must be a URL
  • The "authors" key is required
  • The "authors" value must be a non-empty array
  • The "authors" values must be non-blank stringsĀ¹
  • The "authors" values must not have duplicates
  • The "authors" values are treated case-insensitively
  • The "contributors" key is optional
  • The "contributors" value must be an array
  • The "contributors" values must be non-blank stringsĀ¹
  • The "contributors" values must not have duplicates
  • The "contributors" values are treated case-insensitively
  • Users can only be listed in either the "authors" or "contributors" array (no overlap)
  • The "files.solution" key is required
  • The "files.solution" value must be a non-empty array
  • The "files.solution" values must not have duplicates
  • The "files.test" key is required
  • The "files.test" value must be a non-empty array
  • The "files.test" values must not have duplicates
  • The "files.exemplar" key is required
  • The "files.exemplar" value must be a non-empty array
  • The "files.exemplar" values must not have duplicates
  • The "files.editor" key is optional
  • The "files.editor" value must be an array
  • The "files.editor" values must not have duplicates
  • The "files.invalidator" key is optional
  • The "files.invalidator" value must be an array
  • The "files.invalidator" values must not have duplicates
  • The files listed in the "files.solution" must exist
  • The files listed in the "files.test" must exist
  • The files listed in the "files.exemplar" must exist
  • The files listed in the "files.editor" must exist
  • The files listed in the "files.invalidator" must exist
  • Files can only be listed in either the "files.solution", "files.test", "files.exemplar" or "files.invalidator" array (no overlap)
    • If the track is d or plsql, the "files.solution" and "files.test" files can overlap
  • The "forked_from" key is optional
  • The "forked_from" value must be an array
  • The "forked_from" values must be strings formatted as <track-slug>/<exercise-slug> (e.g. fsharp/bird-watcher)
  • The "forked_from" values must refer to actually implemented exercises
  • The "forked_from" values must not have duplicates
  • The "language_versions" key is optional
  • The "language_versions" value must be a string
  • The "representer.version" key is optional
  • The "representer.version" value must be an integer >= 1
  • The "icon" key is optional
  • The "icon" value must be a kebab-case stringĀ²

Rule: exercises/concept/<slug>/.docs/hints.md is valid

  • The Markdown must conform to the Markdown standards
  • All headings must be either ## General or ## X. <task> where X matches the task number heading in the instructions.md
  • All hints must be specified as Markdown list items
  • Links must be absolute (relative links are not allowed)

Rule: exercises/concept/<slug>/.docs/instructions.md is valid

  • The Markdown must conform to the Markdown standards
  • All tasks must start with a level two heading that starts with a number followed by a dot: ## 1. Do X
  • Links must be absolute (relative links are not allowed)

Rule: exercises/concept/<slug>/.docs/instructions.md.tpl is valid (if present)

  • Each concept placeholders's concept must match the "concepts.slug" property of one of the concepts in the track's config.json.

Rule: exercises/concept/<slug>/.docs/introduction.md is valid

  • The Markdown must conform to the Markdown standards
  • Links must be absolute (relative links are not allowed)

Rule: exercises/practice/<slug>/.meta/config.json is valid

  • The file must be valid JSON
  • The JSON root must be an object
  • The "blurb" key is required
  • The "blurb" value must be a non-blank stringĀ¹ with length <= 350
  • The "source" key is optional
  • The "source" value must be a non-blank stringĀ¹
  • The "source_url" key is optional
  • The "source_url" value must be a URL
  • The "authors" key is optional
  • The "authors" value must be an array
  • The "authors" values must be non-blank stringsĀ¹
  • The "authors" values must not have duplicates
  • The "authors" values are treated case-insensitively
  • The "contributors" key is optional
  • The "contributors" value must be an array
  • The "contributors" values must be non-blank stringsĀ¹
  • The "contributors" values must not have duplicates
  • The "contributors" values are treated case-insensitively
  • Users can only be listed in either the "authors" or "contributors" array (no overlap)
  • The "files.solution" key is required
  • The "files.solution" value must be a non-empty array
  • The "files.solution" values must not have duplicates
  • The "files.test" key is required
  • The "files.test" value must be a non-empty array
  • The "files.test" values must not have duplicates
  • The "files.example" key is required
  • The "files.example" value must be a non-empty array
  • The "files.example" values must not have duplicates
  • The "files.editor" key is optional
  • The "files.editor" value must be an array
  • The "files.editor" values must not have duplicates
  • The "files.invalidator" key is optional
  • The "files.invalidator" value must be an array
  • The "files.invalidator" values must not have duplicates
  • The files listed in the "files.solution" must exist
  • The files listed in the "files.test" must exist
  • The files listed in the "files.example" must exist
  • The files listed in the "files.editor" must exist
  • The files listed in the "files.invalidator" must exist
  • Files can only be listed in either the "files.solution", "files.test", "files.example or "files.invalidator" array (no overlap)
    • If the track is d or plsql, the "files.solution" and "files.test" files can overlap
  • The "language_versions" key is optional
  • The "language_versions" value must be a string
  • The "test_runner" key is optional
  • The "test_runner" value must be a boolean
  • The "representer.version" key is optional
  • The "representer.version" value must be an integer >= 1
  • The "icon" key is optional
  • The "icon" value must be a kebab-case stringĀ²

Rule: exercises/{concept|practice}/<slug>/.approaches/config.json is valid

  • The file's presence is optional, unless there is a introduction.md or a sibling directory
  • The file must be valid JSON
  • The JSON root must be an object
  • The "introduction.authors" key is optional
  • The "introduction.authors" value must be an array
  • The "introduction.authors" values must be non-blank stringsĀ¹
  • The "introduction.authors" values must not have duplicates
  • The "introduction.authors" values are treated case-insensitively
  • If the "introduction.authors" array is non-empty, there must be a non-empty introduction.md file
  • The "introduction.contributors" key is optional
  • The "introduction.contributors" value must be an array
  • The "introduction.contributors" values must be non-blank stringsĀ¹
  • The "introduction.contributors" values must not have duplicates
  • The "introduction.contributors" values are treated case-insensitively
  • If the "introduction.contributors" array is non-empty, there must be a non-empty introduction.md file
  • Users can only be listed in either the "introduction.authors" or "introduction.contributors" array (no overlap)
  • The "approaches" key is optional, unless there is a sibling directory present (which contains the approach' files)
  • The "approaches" value must be an array of objects
  • The "approaches[].uuid" key is required
  • The "approaches[].uuid" value must be a unique version 4 UUID stringā¶
  • The "approaches[].uuid" value for each concept must never change
  • The "approaches[].slug" key is required
  • The "approaches[].slug" value must be a kebab-case stringĀ² with length <= 255
  • The "approaches[].slug" value must have a corresponding non-empty <slug>/content.md file
  • The "approaches[].slug" value must have a corresponding non-empty <slug>/snippet.txt file
  • The "approaches[].title" key is required
  • The "approaches[].title" value must be a Title Case stringĀ³ with length <= 255
  • The "approaches[].blurb" key is required
  • The "approaches[].blurb" value must be a non-blank stringĀ¹ with length <= 350
  • The "approaches[].authors" key is required
  • The "approaches[].authors" value must be a non-empty array
  • The "approaches[].authors" values must be non-blank stringsĀ¹
  • The "approaches[].authors" values must not have duplicates
  • The "approaches[].authors" values are treated case-insensitively
  • The "approaches[].contributors" key is optional
  • The "approaches[].contributors" value must be an array
  • The "approaches[].contributors" values must be non-blank stringsĀ¹
  • The "approaches[].contributors" values must not have duplicates
  • The "approaches[].contributors" values are treated case-insensitively
  • Users can only be listed in either the "approaches[].authors" or "approaches[].contributors" array (no overlap)

Rule: exercises/{concept|practice}/<slug>/.approaches/<approach-slug>/content.md is valid

  • The file's presence is required if a matching "approaches[].slug" entry exists in the .approaches/config.json file
  • The Markdown must conform to the Markdown standards
  • Links must be absolute (relative links are not allowed)

Rule: exercises/{concept|practice}/<slug>/.approaches/<approach-slug>/snippet.<snippet-extension> is valid

  • The file's presence is required if a matching "approaches[].slug" entry exists in the .approaches/config.json file
  • The snippet must have at most 8 lines
  • The snippet extension is taken from the approaches.snippet_extension value in the track's config.json file

Rule: exercises/{concept|practice}/<slug>/.articles/config.json is valid

  • The file's presence is optional, unless there is a sibling directory
  • The file must be valid JSON
  • The JSON root must be an object
  • The "articles" key is optional, unless there is a sibling directory present (which contains the article' files)
  • The "articles" value must be an array of objects
  • The "articles[].uuid" key is required
  • The "articles[].uuid" value must be a unique version 4 UUID stringā¶
  • The "articles[].uuid" value for each concept must never change
  • The "articles[].slug" key is required
  • The "articles[].slug" value must be a kebab-case stringĀ² with length <= 255
  • The "articles[].slug" value must have a corresponding non-empty <slug>/content.md file
  • The "articles[].slug" value must have a corresponding non-empty <slug>/snippet.md file
  • The "articles[].title" key is required
  • The "articles[].title" value must be a Title Case stringĀ³ with length <= 255
  • The "articles[].blurb" key is required
  • The "articles[].blurb" value must be a non-blank stringĀ¹ with length <= 350
  • The "articles[].authors" key is required
  • The "articles[].authors" value must be a non-empty array
  • The "articles[].authors" values must be non-blank stringsĀ¹
  • The "articles[].authors" values must not have duplicates
  • The "articles[].authors" values are treated case-insensitively
  • The "articles[].contributors" key is optional
  • The "articles[].contributors" value must be an array
  • The "articles[].contributors" values must be non-blank stringsĀ¹
  • The "articles[].contributors" values must not have duplicates
  • The "articles[].contributors" values are treated case-insensitively
  • Users can only be listed in either the "articles[].authors" or "articles[].contributors" array (no overlap)

Rule: exercises/{concept|practice}/<slug>/.articles/<article-slug>/content.md is valid

  • The file's presence is required if a matching "articles[].slug" entry exists in the .articles/config.json file
  • The Markdown must conform to the Markdown standards
  • Links must be absolute (relative links are not allowed)

Rule: exercises/{concept|practice}/<slug>/.articles/<article-slug>/snippet.md is valid

  • The file's presence is required if a matching "articles[].slug" entry exists in the .articles/config.json file
  • The Markdown must conform to the Markdown standards
  • The snippet must have at most 8 lines (leading and trailing code fence markers are ignored)

Rule: exercises/shared/.docs/debug.md is valid

  • The file's presence is optional
  • The Markdown must conform to the Markdown standards
  • Links must be absolute (relative links are not allowed)

Rule: exercises/shared/.docs/help.md is valid

  • The file's presence is required
  • The Markdown must conform to the Markdown standards
  • Links must be absolute (relative links are not allowed)

Rule: exercises/shared/.docs/tests.md is valid

  • The file's presence is required
  • The Markdown must conform to the Markdown standards
  • Links must be absolute (relative links are not allowed)

Rule: concepts/<slug>/about.md is valid

  • The Markdown must conform to the Markdown standards
  • Links must be absolute (relative links are not allowed)

Rule: concepts/<slug>/introduction.md is valid

  • The Markdown must conform to the Markdown standards
  • Links must be absolute (relative links are not allowed)
  • The file must be valid JSON
  • The JSON root must be an array
  • The "[].url" property is required
  • The "[].url" value must be an URL
  • The "[].description" property is required
  • The "[].description" value must be a non-blank stringĀ¹
  • The "[].icon_url" property is optional
  • The "[].icon_url" value must be an URL

Rule: concept/<slug>/.meta/config.json is valid

  • The file must be valid JSON
  • The JSON root must be an object
  • The "blurb" key is required
  • The "blurb" value must be a non-blank stringĀ¹ with length <= 350
  • The "authors" key is required
  • The "authors" value must be an array
  • The "authors" values must be non-blank stringsĀ¹
  • The "authors" values must not have duplicates
  • The "authors" values are treated case-insensitively
  • The "contributors" key is optional
  • The "contributors" value must be an array
  • The "contributors" values must be non-blank stringsĀ¹
  • The "contributors" values must not have duplicates
  • The "contributors" values are treated case-insensitively
  • Users can only be listed in either the "authors" or "contributors" array (no overlap)

Rule: docs/ABOUT.md is valid

  • The file's presence is required
  • The file's contents must be non-blank
  • The Markdown must conform to the Markdown standards
  • Links must be absolute (relative links are not allowed)

Rule: docs/INSTALLATION.md is valid

  • The file's presence is required
  • The file's contents must be non-blank
  • The Markdown must conform to the Markdown standards
  • Links must be absolute (relative links are not allowed)

Rule: docs/LEARNING.md is valid

  • The file's presence is required
  • The file's contents must be non-blank
  • The Markdown must conform to the Markdown standards
  • Links must be absolute (relative links are not allowed)

Rule: docs/RESOURCES.md is valid

  • The file's presence is required
  • The file's contents must be non-blank
  • The Markdown must conform to the Markdown standards
  • Links must be absolute (relative links are not allowed)

Rule: docs/SNIPPET.txt is valid

  • The file's presence is required
  • The file's contents must be non-blank

Rule: docs/TESTS.md is valid

  • The file's presence is required
  • The file's contents must be non-blank
  • The Markdown must conform to the Markdown standards
  • Links must be absolute (relative links are not allowed)

Glossary

  1. Non-blank string: a string that contains at least one non-whitespace character.

  2. kebab-case string: a string that contains only characters in the range [a-z0-9], optionally separated by dashes (e.g. "two-fer"). It must match the regular expression: ^[a-z0-9]+(-[a-z0-9]+)*$

  3. Title Case string: a non-blank string that follows the below guidelines from the Chicago Manual of Style:

    • Capitalize the first and last words of titles and subtitles.
    • Capitalize "major" words (nouns, pronouns, verbs, adjectives, adverbs, and some conjunctions).
    • Lowercase the conjunctions and, but, for, or, and nor.
    • Lowercase the articles the, a, and an.
    • Lowercase prepositions, regardless of length, except when they are stressed, are used adverbially or adjectivally, or are used as conjunctions.
    • Lowercase the words to and as.
    • Lowercase the second part of Latin species names.
  4. Sentence Case string: a non-blank string that follows the below guidelines:

    • Capitalize the first word of the sentence, as well as proper nouns and other words as required by a more specific rule.
  5. Valid files pattern: A non-blank stringĀ¹ that specifies a location of a file used in an exercise, relative to the exercise's directory. A pattern may use one of the following placeholders:

    • %{kebab_slug}: the kebab-case exercise slug (e.g. bit-manipulation)
    • %{snake_slug}: the snake_case exercise slug (e.g. bit_manipulation)
    • %{camel_slug}: the camelCase exercise slug (e.g. bitManipulation)
    • %{pascal_slug}: the PascalCase exercise slug (e.g. BitManipulation)
  6. Unique version 4 UUID string: A string that satisfies all of these conditions:

    • It only exists once in the track-level config.json file of a given Exercism track
    • It does not exist in the track-level config.json file of any other Exercism track
    • It does not exist in any canonical-data.json file in https://github.com/exercism/problem-specifications
    • It does not exist anywhere else on Exercism
    • It matches the regular expression:
    ^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$
    

    For example, the below UUID has the correct form:

    d334ffe3-657e-4725-a950-290b284b6d9f
    

    You can run configlet uuid to generate a suitable UUID.