Set up dead link checker in CI (exercism#1330)

Co-authored-by: Angelika Tyborska <[email protected]>

.github/workflows/ci.yml

@@ -114,3 +114,24 @@ jobs:
 
       - name: Run Checks
         run: bin/ci.sh
+
+  linkChecker:
+    name: Link Checker
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Retrieve Lychee Cache
+        uses: actions/cache@v3
+        id: lychee-cache # id to use in retrieve action
+        with:
+          path: .lycheecache
+          key: lychee-v1
+
+      - name: Link Checker
+        uses: lycheeverse/lychee-action@v1
+        with:
+          args: --cache --max-cache-age 7d --require-https --user-agent "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.75 Safari/537.36" --no-progress './**/*.md' './**/*.html' './**/*.json'
+          fail: true
+        env:
+          GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}

.github/workflows/pr.ci.yml

@@ -121,3 +121,24 @@ jobs:
 
       - name: Run exercism/elixir ci (runs tests)
         run: bin/pr.sh
+
+  linkChecker:
+    name: Link Checker
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Retrieve Lychee Cache
+        uses: actions/cache@v3
+        id: lychee-cache # id to use in retrieve action
+        with:
+          path: .lycheecache
+          key: lychee-v1
+
+      - name: Link Checker
+        uses: lycheeverse/lychee-action@v1
+        with:
+          args: --cache --max-cache-age 7d --require-https --user-agent "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.75 Safari/537.36" --no-progress './**/*.md' './**/*.html' './**/*.json'
+          fail: true
+        env:
+          GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}

.lycheeignore

@@ -0,0 +1,7 @@
+irc://irc.libera.chat/elixir
+collinsdictionary\.com
+users.csc.calpoly.edu
+github.com/pulls
+twitter.com
+regexr.com
+papyr.com

CONTRIBUTING.md

@@ -42,7 +42,7 @@ Please keep the following in mind:
 
 - For practice exercises, `instructions.md` come from the [problem specifications](https://github.com/exercism/problem-specifications) repository. They cannot be changed without updating them in that repository first. If Elixir-specific changes are necessary, than can be appended to the instructions by creating a `instructions.append.md` file.
 
-- For practice exercises, use typespecs in the example and template files as described [here](http://elixir-lang.org/getting-started/typespecs-and-behaviours.html).
+- For practice exercises, use typespecs in the example and template files as described [here](https://elixir-lang.org/getting-started/typespecs-and-behaviours.html).
 
 - Each practice exercise test file should have a `test_helper.exs` with code like the following at the top of the file.
   This allows the tests to be run on CI and configures tests to be skipped with the `:pending` flag.

README.md

@@ -9,7 +9,7 @@
 ## Setup
 
 The exercises currently target Elixir versions from 1.10 to 1.15 and Erlang/OTP versions from 21 to 26. Detailed installation instructions can be found at
-[http://elixir-lang.org/install.html](http://elixir-lang.org/install.html). We recommend using the [asdf version manager](https://github.com/asdf-vm/asdf) to manage multiple Elixir versions.
+[https://elixir-lang.org/install.html](https://elixir-lang.org/install.html). We recommend using the [asdf version manager](https://github.com/asdf-vm/asdf) to manage multiple Elixir versions.
 
 ## Testing
 

concepts/docs/about.md

@@ -99,7 +99,7 @@ If a module or a function is intended for internal usage only, you can mark it w
 [hexdocs-pm]: https://hexdocs.pm/
 [writing-documentation-recommendations]: https://hexdocs.pm/elixir/writing-documentation.html#recommendations
 [intellij-elixir-documentation]: https://github.com/KronicDeth/intellij-elixir#quick-documentation
-[vsc-documentation]: https://thinkingelixir.com/elixir-in-vs-code/#Documentation_displayed_on_hover
+[vsc-documentation]: https://fly.io/phoenix-files/setup-vscode-for-elixir-development/
 [iex-h]: https://hexdocs.pm/iex/IEx.Helpers.html#h/1
 [getting-started-iex]: https://elixir-lang.org/getting-started/introduction.html#interactive-mode
 [hiding-internal-modules-and-functions]: https://hexdocs.pm/elixir/writing-documentation.html#hiding-internal-modules-and-functions

concepts/erlang-libraries/about.md

@@ -36,21 +36,21 @@ Elixir interoperability with Erlang libraries is not limited to Erlang's standar
 
 [erlang]: https://en.wikipedia.org/wiki/Erlang_(programming_language)
 [beam]: https://en.wikipedia.org/wiki/BEAM_(Erlang_virtual_machine)
-[erl-stdlib-ref]: http://www.erlang.org/doc/apps/stdlib/index.html
-[erl-timer-sleep]: http://www.erlang.org/doc/man/timer.html#sleep-1
-[erl-timer-send-after]: http://www.erlang.org/doc/man/timer.html#send_after-2
-[erl-timer-send-interval]: http://www.erlang.org/doc/man/timer.html#send_interval-2
-[erl-rand-uniform]: http://www.erlang.org/doc/man/rand.html#uniform-0
-[erl-rand-normal]: http://www.erlang.org/doc/man/rand.html#normal-0
-[erl-rand-seed-2]: http://www.erlang.org/doc/man/rand.html#seed-2
-[erl-io-lib-format]: http://www.erlang.org/doc/man/io_lib.html#format-2
-[erl-math-sin]: http://www.erlang.org/doc/man/math.html#sin-1
-[erl-math-cos]: http://www.erlang.org/doc/man/math.html#cos-1
-[erl-math-log2]: http://www.erlang.org/doc/man/math.html#log2-1
-[erl-math-log10]: http://www.erlang.org/doc/man/math.html#log10-1
-[erl-math-pow]: http://www.erlang.org/doc/man/math.html#pow-2
-[erl-queue]: http://www.erlang.org/doc/man/queue.html
-[erl-crypto]: http://www.erlang.org/doc/man/crypto.html
-[erl-zip]: http://www.erlang.org/doc/man/zip.html
+[erl-stdlib-ref]: https://www.erlang.org/doc/apps/stdlib/index.html
+[erl-timer-sleep]: https://www.erlang.org/doc/man/timer.html#sleep-1
+[erl-timer-send-after]: https://www.erlang.org/doc/man/timer.html#send_after-2
+[erl-timer-send-interval]: https://www.erlang.org/doc/man/timer.html#send_interval-2
+[erl-rand-uniform]: https://www.erlang.org/doc/man/rand.html#uniform-0
+[erl-rand-normal]: https://www.erlang.org/doc/man/rand.html#normal-0
+[erl-rand-seed-2]: https://www.erlang.org/doc/man/rand.html#seed-2
+[erl-io-lib-format]: https://www.erlang.org/doc/man/io_lib.html#format-2
+[erl-math-sin]: https://www.erlang.org/doc/man/math.html#sin-1
+[erl-math-cos]: https://www.erlang.org/doc/man/math.html#cos-1
+[erl-math-log2]: https://www.erlang.org/doc/man/math.html#log2-1
+[erl-math-log10]: https://www.erlang.org/doc/man/math.html#log10-1
+[erl-math-pow]: https://www.erlang.org/doc/man/math.html#pow-2
+[erl-queue]: https://www.erlang.org/doc/man/queue.html
+[erl-crypto]: https://www.erlang.org/doc/man/crypto.html
+[erl-zip]: https://www.erlang.org/doc/man/zip.html
 [erl-calendar]: https://www.erlang.org/doc/man/calendar.html
 [erl-calendar-iso-week-number]: https://www.erlang.org/doc/man/calendar.html#iso_week_number-1

concepts/erlang-libraries/introduction.md

@@ -22,4 +22,4 @@ The most commonly used Erlang functions that do not have an Elixir equivalent ar
 
 To discover Erlang's standard library, explore the [STDLIB Reference Manual][erl-stdlib-ref].
 
-[erl-stdlib-ref]: http://www.erlang.org/doc/apps/stdlib/index.html
+[erl-stdlib-ref]: https://www.erlang.org/doc/apps/stdlib/index.html

concepts/erlang-libraries/links.json

@@ -4,7 +4,7 @@
     "description": "Getting Started - Erlang libraries"
   },
   {
-    "url": "http://www.erlang.org/doc/apps/stdlib/index.html",
+    "url": "https://www.erlang.org/doc/apps/stdlib/index.html",
     "description": "Erlang's STDLIB Reference Manual "
   }
 ]

concepts/pattern-matching/about.md

@@ -47,7 +47,7 @@ end
   # => ** (FunctionClauseError) no function clause matching in Example.named_function/1
   ```
 
-[assertive-style]: http://blog.plataformatec.com.br/2014/09/writing-assertive-code-with-elixir/
+[assertive-style]: https://blog.plataformatec.com.br/2014/09/writing-assertive-code-with-elixir/
 [pattern-match-doc]: https://elixir-lang.org/getting-started/pattern-matching.html
 [match-op]: https://hexdocs.pm/elixir/Kernel.SpecialForms.html#=/2
 [getting-started-pin-operator]: https://elixir-lang.org/getting-started/pattern-matching.html#the-pin-operator

concepts/randomness/about.md

@@ -68,11 +68,11 @@ The random values returned by `Enum.random` and the Erlang's `rand` module are n
 [enum-random]: https://hexdocs.pm/elixir/Enum.html#random/1
 [enum-take-random]: https://hexdocs.pm/elixir/Enum.html#take_random/2
 [enum-shuffle]: https://hexdocs.pm/elixir/Enum.html#shuffle/1
-[erl-rand]: http://www.erlang.org/doc/man/rand.html
-[erl-crypto-strong-rand-bytes]: http://www.erlang.org/doc/man/crypto.html#strong_rand_bytes-1
+[erl-rand]: https://www.erlang.org/doc/man/rand.html
+[erl-crypto-strong-rand-bytes]: https://www.erlang.org/doc/man/crypto.html#strong_rand_bytes-1
 [cryptographically-secure-rng]: https://en.wikipedia.org/wiki/Cryptographically_secure_pseudorandom_number_generator
 [normal-distribution]: https://en.wikipedia.org/wiki/Normal_distribution
-[erl-rand-normal-0]: http://www.erlang.org/doc/man/rand.html#normal-0
-[erl-rand-normal-2]: http://www.erlang.org/doc/man/rand.html#normal-2
+[erl-rand-normal-0]: https://www.erlang.org/doc/man/rand.html#normal-0
+[erl-rand-normal-2]: https://www.erlang.org/doc/man/rand.html#normal-2
 [prng]: https://en.wikipedia.org/wiki/Pseudorandom_number_generator
-[rand-seed-2]: http://www.erlang.org/doc/man/rand.html#seed-2
+[rand-seed-2]: https://www.erlang.org/doc/man/rand.html#seed-2

concepts/randomness/links.json

@@ -4,7 +4,7 @@
     "description": "Documentation: `Enum.random/1`"
   },
   {
-    "url": "http://www.erlang.org/doc/man/rand.html",
+    "url": "https://www.erlang.org/doc/man/rand.html",
     "description": "Erlang `rand`"
   }
 ]

concepts/typespecs/about.md

@@ -85,5 +85,5 @@ On the other hand, `string()` is a different type. It's an Erlang string, in Eli
 [string-t]: https://hexdocs.pm/elixir/String.html#t:t/0
 [enum-t]: https://hexdocs.pm/elixir/Enum.html#t:t/0
 [range-t]: https://hexdocs.pm/elixir/Range.html#t:t/0
-[dialyzer]: http://www.erlang.org/doc/man/dialyzer.html
+[dialyzer]: https://www.erlang.org/doc/man/dialyzer.html
 [dialyxir]: https://hexdocs.pm/dialyxir/readme.html

docs/INSTALLATION.md

@@ -2,7 +2,7 @@
 
 ## Installation
 
-Detailed installation instructions can be found at [elixir-lang.org/install](http://elixir-lang.org/install.html).
+Detailed installation instructions can be found at [elixir-lang.org/install](https://elixir-lang.org/install.html).
 
 For best learning experience on Exercism, we recommend installing locally the same language versions as are used to run tests on your exercise submissions.
 Those versions are **Erlang/OTP 26 and Elixir 1.15**.

docs/LEARNING.md

@@ -3,15 +3,15 @@
 We recommend learning Elixir by working through the syllabus and learning exercises on Exercism.
 They were designed to teach you Elixir from scratch.
 
-The official [Elixir Getting Started Guide](http://elixir-lang.org/getting-started/introduction.html) is also an excellent place to start.
+The official [Elixir Getting Started Guide](https://elixir-lang.org/getting-started/introduction.html) is also an excellent place to start.
 
 ## Additional learning resources
 
-* [Elixir Getting Started Guide](http://elixir-lang.org/getting-started/introduction.html)
+* [Elixir Getting Started Guide](https://elixir-lang.org/getting-started/introduction.html)
 * [Elixir Documentation](https://hexdocs.pm/elixir/)
 * [Programming Elixir](https://pragprog.com/titles/elixir16/programming-elixir-1-6/), by Dave Thomas
 * [Elixir in Action](https://www.manning.com/books/elixir-in-action-second-edition), by Saša Jurić
-* [StackOverflow](http://stackoverflow.com/questions/tagged/elixir)
+* [StackOverflow](https://stackoverflow.com/questions/tagged/elixir)
 * [Introducing Elixir](https://www.oreilly.com/library/view/introducing-elixir-2nd/9781491956847/), by Simon St. Laurent, J. David Eisenberg
 * [Elixir School](https://elixirschool.com)
 * [Joy of Elixir](https://joyofelixir.com/toc.html)

docs/RESOURCES.md

@@ -9,13 +9,13 @@
 ## Communication channels
 
 * [Elixir Forum](https://elixirforum.com/)
-* [Slack](https://elixir-slackin.herokuapp.com/)
+* [Slack](https://elixir-lang.slack.com/)
 * [Discord](https://discord.gg/elixir)
 * [Official #elixir on irc.libera.chat](irc://irc.libera.chat/elixir)
 
 ## Elixir Podcasts
 
-- [Thinking Elixir](https://thinkingelixir.com/the-podcast/)
+- [Thinking Elixir](https://podcast.thinkingelixir.com/)
 - [Elixir Wizards](https://smartlogic.io/podcast/elixir-wizards/)
 - [Elixir Mix](https://devchat.tv/elixir-mix/)
 - [Elixir Outlaws](https://elixiroutlaws.com/)

docs/TESTS.md

@@ -142,9 +142,9 @@ typically follow the `@spec function_name(type1, type2) :: return_type`
 format. These are used in Elixir and Erlang as documentation and
 in conjunction with a tool called Dialyzer to find type inconsistencies
 and possible bugs. For more information see the
-[Elixir typespecs guide](http://elixir-lang.org/getting-started/typespecs-and-behaviours.html)
+[Elixir typespecs guide](https://elixir-lang.org/getting-started/typespecs-and-behaviours.html)
 or the [typespecs documentation](https://hexdocs.pm/elixir/typespecs.html). For
-documentation about Dialyzer see [Erlang -- dialyzer](http://www.erlang.org/doc/man/dialyzer.html).
+documentation about Dialyzer see [Erlang -- dialyzer](https://www.erlang.org/doc/man/dialyzer.html).
 
 Optionally, you may want to check
 the types of your implementation with Dialyzer. There are a couple

exercises/concept/captains-log/.docs/hints.md

@@ -33,6 +33,6 @@
 [getting-started-erlang-libraries]: https://elixir-lang.org/getting-started/erlang-libraries.html
 [getting-started-formatted-text-output]: https://elixir-lang.org/getting-started/erlang-libraries.html#formatted-text-output
 [enum-random]: https://hexdocs.pm/elixir/Enum.html#random/1
-[erl-rand-uniform]: http://www.erlang.org/doc/man/rand.html#uniform-0
-[erl-io-lib-format]: http://www.erlang.org/doc/man/io_lib.html#format-2
+[erl-rand-uniform]: https://www.erlang.org/doc/man/rand.html#uniform-0
+[erl-io-lib-format]: https://www.erlang.org/doc/man/io_lib.html#format-2
 [to-string]: https://hexdocs.pm/elixir/Kernel.html#to_string/1

exercises/concept/captains-log/.docs/introduction.md

@@ -30,4 +30,4 @@ The most commonly used Erlang functions that do not have an Elixir equivalent ar
 
 To discover Erlang's standard library, explore the [STDLIB Reference Manual][erl-stdlib-ref].
 
-[erl-stdlib-ref]: http://www.erlang.org/doc/apps/stdlib/index.html
+[erl-stdlib-ref]: https://www.erlang.org/doc/apps/stdlib/index.html

exercises/concept/log-parser/.docs/hints.md

@@ -14,7 +14,7 @@
 ## 1. Identify garbled log lines
 
 - Use the [`r` sigil][sigil-r] to create a regular expression.
-- There is [an operator]([match-operator]) that can be used to check a string against a regular expression. There is also a [`Regex` function][regex-match] and a [`String` function][string-match] that can do the same.
+- There is [an operator][match-operator] that can be used to check a string against a regular expression. There is also a [`Regex` function][regex-match] and a [`String` function][string-match] that can do the same.
 - Don't forget to escape characters that have special meaning in regular expressions.
 
 ## 2. Split the log line

exercises/concept/paint-by-number/.docs/hints.md

@@ -4,7 +4,7 @@
 
 - Read about [bitstrings][bitstring] in the Getting Started guide.
 - Review the documentation for the [bitstring special form][bitstring-form].
-- Review [how to convert decimal numbers to binary numbers]([decimal-to-binary-youtube]).
+- Review [how to convert decimal numbers to binary numbers][decimal-to-binary-youtube].
 - Elixir supports [different ways of writing integers][integer-literal], including binary notation.
 
 ## 1. Calculate palette bit size

exercises/practice/binary/.docs/instructions.md

@@ -2,9 +2,9 @@
 
 Convert a binary number, represented as a string (e.g. '101010'), to its decimal equivalent using first principles.
 
-Implement binary to decimal conversion. Given a binary input
-string, your program should produce a decimal output. The
-program should handle invalid inputs.
+Implement binary to decimal conversion.
+Given a binary input string, your program should produce a decimal output.
+The program should handle invalid inputs.
 
 ## Note
 
@@ -15,8 +15,7 @@ program should handle invalid inputs.
 
 Decimal is a base-10 system.
 
-A number 23 in base 10 notation can be understood
-as a linear combination of powers of 10:
+A number 23 in base 10 notation can be understood as a linear combination of powers of 10:
 
 - The rightmost digit gets multiplied by 10^0 = 1
 - The next number gets multiplied by 10^1 = 10

exercises/practice/binary/.meta/config.json

@@ -31,5 +31,5 @@
   },
   "blurb": "Convert a binary number, represented as a string (e.g. '101010'), to its decimal equivalent using first principles.",
   "source": "All of Computer Science",
-  "source_url": "http://www.wolframalpha.com/input/?i=binary&a=*C.binary-_*MathWorld-"
+  "source_url": "https://www.wolframalpha.com/examples/mathematics/numbers/base-conversions"
 }

exercises/practice/hexadecimal/.meta/config.json

@@ -25,5 +25,5 @@
   },
   "blurb": "Convert a hexadecimal number, represented as a string (e.g. \"10af8c\"), to its decimal equivalent using first principles (i.e. no, you may not use built-in or external libraries to accomplish the conversion).",
   "source": "All of Computer Science",
-  "source_url": "http://www.wolframalpha.com/examples/NumberBases.html"
+  "source_url": "https://www.wolframalpha.com/examples/mathematics/numbers/base-conversions"
 }

exercises/practice/secret-handshake/.meta/config.json

@@ -23,5 +23,5 @@
   },
   "blurb": "Given a decimal number, convert it to the appropriate sequence of events for a secret handshake.",
   "source": "Bert, in Mary Poppins",
-  "source_url": "https://www.imdb.com/title/tt0058331/quotes/qt0437047"
+  "source_url": "https://www.imdb.com/title/tt0058331/quotes/?item=qt0437047"
 }