Update migration script to test run warnings

When running the entire test suite, many warnings would be output:

/Users/bw/Projects/gollum/test/test_migrate.rb:37: warning: already initialized constant HYPHENATE
/Users/bw/Projects/gollum/test/test_migrate.rb:37: warning: previous definition of HYPHENATE was here
/Users/bw/Projects/gollum/test/test_migrate.rb:37: warning: already initialized constant PAGE_FILE_DIR
/Users/bw/Projects/gollum/test/test_migrate.rb:37: warning: previous definition of PAGE_FILE_DIR was here
/Users/bw/Projects/gollum/bin/gollum-migrate-tags:91: warning: already initialized constant REPO
/Users/bw/Projects/gollum/bin/gollum-migrate-tags:91: warning: previous definition of REPO was here
/Users/bw/Projects/gollum/bin/gollum-migrate-tags:236: warning: already initialized constant TREE
/Users/bw/Projects/gollum/bin/gollum-migrate-tags:236: warning: previous definition of TREE was here
/Users/bw/Projects/gollum/test/test_migrate.rb:37: warning: already initialized constant PAGE_FILE_DIR
/Users/bw/Projects/gollum/test/test_migrate.rb:37: warning: previous definition of PAGE_FILE_DIR was here
/Users/bw/Projects/gollum/bin/gollum-migrate-tags:91: warning: already initialized constant REPO
/Users/bw/Projects/gollum/bin/gollum-migrate-tags:91: warning: previous definition of REPO was here
/Users/bw/Projects/gollum/bin/gollum-migrate-tags:236: warning: already initialized constant TREE
/Users/bw/Projects/gollum/bin/gollum-migrate-tags:236: warning: previous definition of TREE was here

While it's unlikely that end users would ever see these warnings, as
they'd only be running the migration script once, they will always be
shown in our local test runs and CI run output.

So instead of using constants in our migration script, I change the
script to use class variables instead. This should not effect the
functionality of the migration script whatsoever.

bin/gollum-migrate-tags

@@ -11,8 +11,11 @@ migrate_options = {
   :hyphenate => true
 }
 
-def setting(const)
+def setting(variable_name)
-  Object.const_defined?(const.upcase) && Object.const_get(const.upcase)
+  class_variable_name = :"@@#{variable_name.to_s}"
+
+  Object.class_variable_defined?(class_variable_name) &&
+    Object.class_variable_get(class_variable_name)
 end
 
 opts = OptionParser.new do |opts|
@@ -78,8 +81,11 @@ end
 begin
   opts.parse!
   migrate_options.each do |setting, value|
-    const = setting.to_s.upcase
+    variable_name = :"@@#{setting.to_s}"
-    Object.const_set(const, value) unless Object.const_defined?(const)
+
+    unless Object.class_variable_defined?(variable_name)
+      Object.class_variable_set(variable_name, value)
+    end
   end
   wiki_options[:page_file_dir] = setting(:page_file_dir) ? setting(:page_file_dir) : wiki_options[:page_file_dir] # Allow settings :page_file_dir through PAGE_FILE_DIR constant.
 rescue OptionParser::InvalidOption
@@ -88,7 +94,7 @@ rescue OptionParser::InvalidOption
   exit
 end
 
-REPO = ARGV[0] || Dir.pwd
+wiki_directory = ARGV[0] || Dir.pwd
 
 require 'gollum-lib'
 
@@ -232,8 +238,12 @@ end
 
 filter_chain = [:PlainTextMigrator, :CodeMigrator, :TagMigrator]
 
-wiki = ::Gollum::Wiki.new(REPO, wiki_options.merge({:filter_chain => filter_chain}))
+wiki = ::Gollum::Wiki.new(wiki_directory, wiki_options.merge({:filter_chain => filter_chain}))
-TREE = wiki.tree_list(wiki.ref, true, true).map {|file| ::File.join('/', file.path)}
+
+Object.class_variable_set(
+  :"@@wiki_tree",
+  wiki.tree_list(wiki.ref, true, true).map {|file| ::File.join('/', file.path)}
+)
 
 def find_linked(link)
   link.gsub!(' ', '-') if setting(:hyphenate) # Match paths containing dashes instead of spaces
@@ -243,7 +253,9 @@ def find_linked(link)
   test_path = ::File.extname(link).empty? ? /#{link}\..+/ : link
   # Select pages from the wiki whose path =~ 'Foo/Bar/Samwi.*'
   # Match case-insenstively to mimic 4.x behavior!
-  TREE.select {|path| path =~ /^\/(.*\/)?#{test_path}/i}
+  Object.class_variable_get(:"@@wiki_tree").select { |path|
+    path =~ /^\/(.*\/)?#{test_path}/i
+  }
 end
 
 def log(kind, msg = nil)

test/test_migrate.rb

@@ -1,28 +1,6 @@
 # ~*~ encoding: utf-8 ~*~
 require File.expand_path(File.join(File.dirname(__FILE__), 'helper'))
 
-# Original contents of Subdir/Foo.md:
-# waa
-# [[Samwi]]
-# [[samwise gamgee.mediaWiki]]
-# [[Samwise Gamgee.mediawiki]]
-# [[Samwise Gamgee]]
-# [[Test|Samwise Gamgee#Anchor]]
-# [[Waaa|Test]]
-# [[Zaa]]
-
-# Contents of Subdir/Foo.md after successful tag migration
-result = <<EOF
-waa
-[[Samwi]]
-[[/Samwise Gamgee.mediawiki]]
-[[/Samwise Gamgee.mediawiki]]
-[[/Samwise Gamgee.md]]
-[[Test|/Samwise Gamgee.md#Anchor]]
-[[Waaa|/Bar/Test.md]]
-[[Subsub/Zaa.md]]
-EOF
-
 def load_script(**args)
   settings = {
     :run_silent => true,
@@ -32,9 +10,12 @@ def load_script(**args)
     :page_file_dir => nil,
   }.merge(args)
 
-  settings.each do |const, val|
+  settings.each do |setting, val|
-    const_name = const.to_s.upcase
+    variable_name = :"@@#{setting.to_s}"
-    Object.const_set(const_name, val) unless Object.const_defined?(const_name) && Object.const_get(const_name) == val
+
+    unless Object.class_variable_defined?(variable_name) && Object.class_variable_get(variable_name) == val
+      Object.class_variable_set(variable_name, val)
+    end
   end
 
   script_path = File.expand_path(File.join(File.dirname(__FILE__), '../', 'bin', 'gollum-migrate-tags'))
@@ -45,7 +26,6 @@ def load_script(**args)
 end
 
 unless ENV['CI']
-
   context '4.x -> 5.x tag migrator' do
     include Rack::Test::Methods
 
@@ -54,10 +34,31 @@ unless ENV['CI']
     end
 
     test 'repair broken links' do
+      # The original contents of Subdir/Foo.md:
+      #
+      # waa
+      # [[Samwi]]
+      # [[samwise gamgee.mediaWiki]]
+      # [[Samwise Gamgee.mediawiki]]
+      # [[Samwise Gamgee]]
+      # [[Test|Samwise Gamgee#Anchor]]
+      # [[Waaa|Test]]
+      # [[Zaa]]
+      #
+      # The contents will be updated after running the migration script.
       load_script
 
-      f = ::File.new(::File.join(@path, 'Subdir/Foo.md'), 'r')
+      file = ::File.new(::File.join(@path, 'Subdir/Foo.md'), 'r')
-      assert_equal result, f.read
+      assert_equal <<~FILE_CONTENTS, file.read
+        waa
+        [[Samwi]]
+        [[/Samwise Gamgee.mediawiki]]
+        [[/Samwise Gamgee.mediawiki]]
+        [[/Samwise Gamgee.md]]
+        [[Test|/Samwise Gamgee.md#Anchor]]
+        [[Waaa|/Bar/Test.md]]
+        [[Subsub/Zaa.md]]
+      FILE_CONTENTS
     end
 
     test 'change spaced filenames to hyphenated filenames' do
@@ -82,5 +83,4 @@ unless ENV['CI']
       FileUtils.rm_rf(@path)
     end
   end
-
 end