Remove language group recursion

[lildude]

After over 11 years within Linguist, and over 5 year of direct usage, it's been discovered Linguist::Language has a recursion problem that doesn't play nicely with Rails' .to_json:

[1] pry(main)> require 'linguist'
=> true
[2] pry(main)> require 'active_support/all'
=> true
[3] pry(main)> ld = Linguist::Language.find_by_name("Markdown")
=> #<Linguist::Language name=Markdown>
[4] pry(main)> ld.to_json
SystemStackError: stack level too deep
from /workspaces/github/vendor/gems/3.1.2/ruby/3.1.0/gems/activesupport-7.1.0.alpha.bb68040de4/lib/active_support/core_ext/object/json.rb:180:in `initialize_dup'
[5] pry(main)> wtf -v
[...]
9152: /workspaces/github/vendor/gems/3.1.2/ruby/3.1.0/gems/activesupport-7.1.0.alpha.bb68040de4/lib/active_support/core_ext/object/json.rb:179:in `as_json'
9153: /workspaces/github/vendor/gems/3.1.2/ruby/3.1.0/gems/activesupport-7.1.0.alpha.bb68040de4/lib/active_support/core_ext/object/json.rb:63:in `as_json'
9154: /workspaces/github/vendor/gems/3.1.2/ruby/3.1.0/gems/activesupport-7.1.0.alpha.bb68040de4/lib/active_support/core_ext/object/json.rb:180:in `block in as_json'
9155: /workspaces/github/vendor/gems/3.1.2/ruby/3.1.0/gems/activesupport-7.1.0.alpha.bb68040de4/lib/active_support/core_ext/object/json.rb:179:in `each'
9156: /workspaces/github/vendor/gems/3.1.2/ruby/3.1.0/gems/activesupport-7.1.0.alpha.bb68040de4/lib/active_support/core_ext/object/json.rb:179:in `as_json'
9157: /workspaces/github/vendor/gems/3.1.2/ruby/3.1.0/gems/activesupport-7.1.0.alpha.bb68040de4/lib/active_support/core_ext/object/json.rb:63:in `as_json'
9158: /workspaces/github/vendor/gems/3.1.2/ruby/3.1.0/gems/activesupport-7.1.0.alpha.bb68040de4/lib/active_support/json/encoding.rb:38:in `encode'
9159: /workspaces/github/vendor/gems/3.1.2/ruby/3.1.0/gems/activesupport-7.1.0.alpha.bb68040de4/lib/active_support/json/encoding.rb:23:in `encode'
9160: /workspaces/github/vendor/gems/3.1.2/ruby/3.1.0/gems/activesupport-7.1.0.alpha.bb68040de4/lib/active_support/core_ext/object/json.rb:42:in `to_json'
9161: (pry):4:in `__pry__'
9162: /workspaces/github/vendor/gems/3.1.2/ruby/3.1.0/gems/pry-0.13.1/lib/pry/pry_instance.rb:290:in `eval'
9163: /workspaces/github/vendor/gems/3.1.2/ruby/3.1.0/gems/pry-0.13.1/lib/pry/pry_instance.rb:290:in `evaluate_ruby'
9164: /workspaces/github/vendor/gems/3.1.2/ruby/3.1.0/gems/pry-0.13.1/lib/pry/pry_instance.rb:659:in `handle_line'
[...]
[6] pry(main)>

Closer examination (ie doing what Rails does) shows where the recursion is:

[7] pry(main)> ld.respond_to?(:to_hash)
=> false
[8] pry(main)> ld.instance_values.as_json
SystemStackError: stack level too deep
from /workspaces/github/vendor/gems/3.1.2/ruby/3.1.0/gems/activesupport-7.1.0.alpha.bb68040de4/lib/active_support/core_ext/object/json.rb:100:in `as_json'
[9] pry(main)> ld.instance_values
=> {"name"=>"Markdown",
 "fs_name"=>nil,
 "type"=>:prose,
 "types"=>[:data, :markup, :programming, :prose],
 "color"=>"#083fa1",
 "aliases"=>["markdown", "pandoc"],
 "tm_scope"=>"source.gfm",
 "ace_mode"=>"markdown",
 "codemirror_mode"=>"gfm",
 "codemirror_mime_type"=>"text/x-gfm",
 "wrap"=>true,
 "language_id"=>222,
 "extensions"=>[".md", ".livemd", ".markdown", ".mdown", ".mdwn", ".mdx", ".mkd", ".mkdn", ".mkdown", ".ronn", ".scd", ".workbook"],
 "interpreters"=>[],
 "filenames"=>["contents.lr"],
 "popular"=>false,
 "group"=>#<Linguist::Language name=Markdown>}
[10] pry(main)> 

💥 there's our recursion: "group"=>#<Linguist::Language name=Markdown>

We don't really need this as we have a group() method which gets the same information as and when it is needed so all we really need is the name.

This PR removes the recursive assignment.

[Alhadis]

11 years? Damn.

[Alhadis]

@lildude One of the tests has started failing for an unfamiliar reason:

  1) Failure:
TestLanguage#test_all_languages_have_a_valid_ace_mode [/home/runner/work/linguist/linguist/test/test_language.rb:420]:
The following languages do not have an Ace mode listed in languages.yml. Please add an Ace mode for all new languages.
If no Ace mode exists for a language, mark the language with `ace_mode: text` in lib/linguist/languages.yml.
Toggle list
ABAP                           abap
AGS Script                     c_cpp
API Blueprint                  markdown
ATS                            ocaml
ActionScript                   actionscript
Ada                            ada
Alpine Abuild                  sh
Altium Designer                ini
ApacheConf                     apache_conf
Apex                           java
Apollo Guidance Computer       assembly_x86
AppleScript                    applescript
AsciiDoc                       asciidoc
Assembly                       assembly_x86
Asymptote                      c_cpp
AutoHotkey                     autohotkey
AutoIt                         autohotkey
Batchfile                      batchfile
Beef                           csharp
BibTeX                         tex
Bluespec                       verilog
C                              c_cpp
C#                             csharp
C++                            c_cpp
C-ObjDump                      assembly_x86
C2hs Haskell                   haskell
COBOL                          cobol
CODEOWNERS                     gitignore
Cabal Config                   haskell
Nunjucks                       nunjucks
OCaml                          ocaml
ObjDump                        assembly_x86
Objective-C                    objectivec
Objective-C++                  objectivec
OpenCL                         c_cpp
OpenRC runscript               sh
OpenSCAD                       scad
PLSQL                          sql
PLpgSQL                        pgsql
Pascal                         pascal
Perl                           perl
PicoLisp                       lisp
Pod                            perl
Pod 6                          perl
PowerShell                     powershell
Procfile                       batchfile
Prolog                         prolog
Protocol Buffer                protobuf
Pug                            jade
PureScript                     haskell
Python                         python
R                              r
RDoc                           rdoc
RMarkdown                      markdown
RPC                            c_cpp
Racket                         lisp
Raku                           perl
ReScript                       rust
Reason                         rust
ReasonLIGO                     rust
Ren'Py                         python
Rouge                          clojure
Ruby                           ruby
Rust                           rust
SCSS                           scss
SQL                            sql
SQLPL                          sql
SRecode Template               lisp
SWIG                           c_cpp
Sage                           python
Sass                           sass
Scala                          scala
Scheme                         scheme
Shell                          sh
ShellCheck Config              ini
ShellSession                   sh
Smarty                         smarty
Squirrel                       c_cpp
Starlark                       python
Stylus                         stylus
SystemVerilog                  verilog
TOML                           toml
TSQL                           sql
Tcl                            tcl
Tcsh                           sh
TeX                            tex
TextMate Properties            properties
Textile                        textile
Twig                           twig
TypeScript                     typescript
Unified Parallel C             c_cpp
Unix Assembly                  assembly_x86
Uno                            csharp
UnrealScript                   java
V                              golang
VHDL                           vhdl
Vala                           vala
Velocity Template Language     velocity
Verilog                        verilog
Volt                           d
WebAssembly                    lisp
Win32 Message File             ini
Windows Registry Entries       ini
X BitMap                       c_cpp
X PixMap                       c_cpp
XC                             c_cpp
XS                             c_cpp
edn                            clojure
wisp                           clojure

Would this have been caused by the changes made in this PR, you think?

[lildude]

Huh‽ 😱 I've never seen that either. I don't see how my changes could have caused this as the test passed in that PR and on master since the PR was merged. I'll dig into it this week.

[lildude]

Yup, this is definitely not my fault 😁 The cause is the upstream Ace repo has had a bit of restructuring in ajaxorg/ace#4851 which means we're looking in the wrong place now. They appear to have missed two files as part of this move for some reason: jsoniq.js and xquery.js our tests will fail on these two.

I've started a PR to fix this in #6002 however I'm investigating if we need to keep the ace_mode property as GitHub hasn't use the Ace editor in a very long time.