cleanup code and add more test coverage

- move Multidb class methods to the multidb.rb instead of multidb/configuration.rb
- cleanup specs (use expect syntax vs should)
- add more test coverage
- reset the threadlocal when resetting multidb
  - caused issues in random testing order otherwise
- add and configure rubocop-rspec

Author: urkle

.rubocop.yml

@@ -1,3 +1,6 @@
+require:
+  - rubocop-rspec
+
 AllCops:
   TargetRubyVersion: 2.5
   SuggestExtensions: false
@@ -24,6 +27,9 @@ Layout/SpaceBeforeBrackets: # new in 1.7
 
 Lint/AmbiguousAssignment: # new in 1.7
   Enabled: true
+Lint/AmbiguousBlockAssociation:
+  IgnoredMethods:
+    - change
 Lint/AmbiguousOperatorPrecedence: # new in 1.21
   Enabled: true
 Lint/AmbiguousRange: # new in 1.19
@@ -89,6 +95,22 @@ Naming/BlockForwarding: # new in 1.24
 Metrics:
   Enabled: false
 
+RSpec/ExampleLength:
+  CountAsOne: [array, heredoc]
+  Max: 9
+RSpec/ExpectChange:
+  EnforcedStyle: block
+RSpec/ImplicitSubject:
+  Enabled: false
+RSpec/NamedSubject:
+  Enabled: false
+RSpec/MultipleMemoizedHelpers:
+  Enabled: false
+RSpec/MultipleExpectations:
+  Enabled: false
+RSpec/NestedGroups:
+  Max: 4
+
 Security/CompoundHash: # new in 1.28
   Enabled: true
 Security/IoMethods: # new in 1.22
@@ -102,6 +124,8 @@ Style/ArrayCoercion:
   Enabled: true
 Style/BisectedAttrAccessor:
   Enabled: true
+Style/BlockDelimiters:
+  Enabled: false
 Style/CaseLikeIf:
   Enabled: true
 Style/CollectionCompact: # new in 1.2

.simplecov

@@ -3,6 +3,8 @@
 SimpleCov.configure do
   enable_coverage :branch
   add_filter '/spec/'
+  add_filter 'lib/multidb/version.rb'
+  add_filter 'lib/ar-multidb.rb'
 
   add_group 'Binaries', '/bin/'
   add_group 'Libraries', '/lib/'

ar-multidb.gemspec

@@ -7,7 +7,7 @@ Gem::Specification.new do |s|
   s.name        = 'ar-multidb'
   s.version     = Multidb::VERSION
   s.authors     = ['Alexander Staubo', 'Edward Rudd']
-  s.email       = ['alex@bengler.no', 'urkle@outoforder.cc']
+  s.email       = %w[alex@bengler.no urkle@outoforder.cc]
   s.homepage    = ''
   s.summary     = s.description = 'Multidb is an ActiveRecord extension for switching between multiple database connections, such as primary/replica setups.'
   s.license     = 'MIT'
@@ -25,7 +25,8 @@ Gem::Specification.new do |s|
 
   s.add_development_dependency 'rake', '~> 13.0'
   s.add_development_dependency 'rspec', '~> 3.8'
-  s.add_development_dependency 'rubocop', '~> 1.28'
+  s.add_development_dependency 'rubocop', '~> 1.28.0'
+  s.add_development_dependency 'rubocop-rspec', '~> 2.10.0'
   s.add_development_dependency 'simplecov', '~> 0.21.2'
   s.add_development_dependency 'simplecov-lcov', '~> 0.8.0'
   s.add_development_dependency 'sqlite3', '~> 1.3'

lib/multidb.rb

@@ -12,3 +12,29 @@
 require_relative 'multidb/candidate'
 require_relative 'multidb/balancer'
 require_relative 'multidb/version'
+
+module Multidb
+  # Error raised when the configuration has not been initialized
+  class NotInitializedError < StandardError; end
+
+  class << self
+    delegate :use, :get, :disconnect!, to: :balancer
+  end
+
+  def self.init(config)
+    activerecord_config = config.dup.with_indifferent_access
+    default_adapter     = activerecord_config
+    configuration_hash  = activerecord_config.delete(:multidb)
+
+    @balancer = Balancer.new(Configuration.new(default_adapter, configuration_hash || {}))
+  end
+
+  def self.balancer
+    @balancer || raise(NotInitializedError, 'Balancer not initialized. You need to run Multidb.init first')
+  end
+
+  def self.reset!
+    @balancer = nil
+    Thread.current[:multidb] = nil
+  end
+end

lib/multidb/balancer.rb

@@ -26,7 +26,7 @@ def initialize(configuration)
     end
 
     def append(databases)
-      databases.each_pair do |name, config|
+      databases.with_indifferent_access.each_pair do |name, config|
         configs = config.is_a?(Array) ? config : [config]
         configs.each do |cfg|
           if cfg['alias']
@@ -51,7 +51,7 @@ def get(name, &_block)
 
       raise ArgumentError, "No such database connection '#{name}'" if candidates.empty?
 
-      candidate = candidates.respond_to?(:sample) ? candidates.sample : candidates[rand(candidates.length)]
+      candidate = candidates.sample
 
       block_given? ? yield(candidate) : candidate
     end

lib/multidb/configuration.rb

@@ -1,28 +1,6 @@
 # frozen_string_literal: true
 
 module Multidb
-  class << self
-    delegate :use, :get, :disconnect!, to: :balancer
-  end
-
-  def self.init(config)
-    activerecord_config = config.dup.with_indifferent_access
-    default_adapter = activerecord_config
-    configuration_hash = activerecord_config.delete(:multidb)
-
-    @balancer = Balancer.new(Configuration.new(default_adapter, configuration_hash || {}))
-  end
-
-  def self.balancer
-    @balancer || raise(NotInitializedError, 'Balancer not initialized. You need to run Multidb.init first')
-  end
-
-  def self.reset!
-    @balancer = nil
-  end
-
-  class NotInitializedError < StandardError; end
-
   class Configuration
     def initialize(default_adapter, configuration_hash)
       @default_handler = ActiveRecord::Base.connection_handler