From 7b993a35b3fc5eb20140a6c6b8d68fc772a7c0cd Mon Sep 17 00:00:00 2001
From: Tan Le <tan.le@hey.com>
Date: Wed, 18 Sep 2024 11:05:57 +1000
Subject: [PATCH] Default .cfg highlight to INI lexer (#2074)

Cisco IOS shares the same extension but we want to limit it given
the relevant content. For other cases such as `setup.cfg`, we would
prefer INI syntax.
---
 lib/rouge/guessers/disambiguation.rb | 6 ++++++
 lib/rouge/lexers/ini.rb              | 2 +-
 spec/lexers/cisco_ios_spec.rb        | 4 +++-
 spec/lexers/ini_spec.rb              | 1 +
 4 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/lib/rouge/guessers/disambiguation.rb b/lib/rouge/guessers/disambiguation.rb
index e3031f7ca5..6f2cfd5d91 100644
--- a/lib/rouge/guessers/disambiguation.rb
+++ b/lib/rouge/guessers/disambiguation.rb
@@ -66,6 +66,12 @@ def match?(filename)
         end
       end
 
+      disambiguate '*.cfg' do
+        next CiscoIos if matches?(/\A\s*(version|banner|interface)\b/)
+
+        INI
+      end
+
       disambiguate '*.pl' do
         next Perl if contains?('my $')
         next Prolog if contains?(':-')
diff --git a/lib/rouge/lexers/ini.rb b/lib/rouge/lexers/ini.rb
index b44014e7b9..ae5464ba5e 100644
--- a/lib/rouge/lexers/ini.rb
+++ b/lib/rouge/lexers/ini.rb
@@ -9,7 +9,7 @@ class INI < RegexLexer
       tag 'ini'
 
       # TODO add more here
-      filenames '*.ini', '*.INI', '*.gitconfig'
+      filenames '*.ini', '*.INI', '*.gitconfig', '*.cfg'
       mimetypes 'text/x-ini'
 
       identifier = /[\w\-.]+/
diff --git a/spec/lexers/cisco_ios_spec.rb b/spec/lexers/cisco_ios_spec.rb
index fb8d836ed9..f8a1b713aa 100644
--- a/spec/lexers/cisco_ios_spec.rb
+++ b/spec/lexers/cisco_ios_spec.rb
@@ -8,7 +8,9 @@
     include Support::Guessing
 
     it 'guesses by filename' do
-      assert_guess :filename => 'foo.cfg'
+      # Disambiguate with INI
+      assert_guess :filename => 'foo.cfg', :source => "version 13.4"
+      assert_guess :filename => 'foo.cfg', :source => "interface FastEthernet0.20"
     end
 
     it 'guesses by mimetype' do
diff --git a/spec/lexers/ini_spec.rb b/spec/lexers/ini_spec.rb
index 3cefe49532..fa1f6c3f84 100644
--- a/spec/lexers/ini_spec.rb
+++ b/spec/lexers/ini_spec.rb
@@ -10,6 +10,7 @@
     it 'guesses by filename' do
       assert_guess :filename => 'foo.ini'
       assert_guess :filename => '.gitconfig'
+      assert_guess :filename => 'setup.cfg', :source => "[metadata]\nname = my_package"
     end
 
     it 'guesses by mimetype' do