Add block methods Rainbow.with_enabled / new_with_enabled to temporarily enable/disable Rainbow

Changelog.md

@@ -2,6 +2,8 @@
 
 ## Unreleased 
 
+- Added block methods `Rainbow.with_enabled(enabled)`/`new_with_enabled(enabled)` to temporarily
+- enable/disable Rainbow
 - Development: Drop `rbx` section in Gemfile. No continued support effort for Rubinius. 
 
 ## 3.1.1 (2022-01-11)

README.markdown

@@ -145,6 +145,12 @@ When disabled all the methods return an unmodified string
 It's enabled by default, unless STDOUT/STDERR is not a TTY or a terminal is
 dumb.
 
+You can temporarily enable/disable Rainbow by using the block form:
+
+```ruby
+Rainbow.with_enabled(true) { Rainbow('not blue').blue } # => 'not blue'
+```
+
 ### Advanced usage
 
 `Rainbow()` and `Rainbow.enabled` operate on the global Rainbow wrapper

lib/rainbow/global.rb

@@ -11,10 +11,37 @@ def self.enabled
     global.enabled
   end
 
+  # Globally enables/disables Rainbow
   def self.enabled=(value)
     global.enabled = value
   end
 
+  # Globally enables/disables Rainbow for the duration of the block
+  #
+  # @example
+  #   Rainbow.with_enabled(true)  { Rainbow('blue').blue }     # => "\e[34mblue\e[0m"
+  #   Rainbow.with_enabled(false) { Rainbow('not blue').blue } # => "not blue"
+  #
+  def self.with_enabled(enabled)
+    orig_enabled, Rainbow.enabled = Rainbow.enabled, enabled # rubocop:disable Style/ParallelAssignment
+    yield
+  ensure
+    Rainbow.enabled = orig_enabled
+  end
+
+  # Yields a new Rainbow instance that is enabled/disabled
+  #
+  # @example
+  #   Rainbow.new_with_enabled(true)  { |rainbow| rainbow.wrap('blue').blue }     # => "\e[34mblue\e[0m"
+  #   Rainbow.new_with_enabled(false) { |rainbow| rainbow.wrap('not blue').blue } # => "not blue"
+  #
+  def self.new_with_enabled(enabled)
+    instance = Rainbow.new
+    instance.enabled = enabled
+    yield instance if block_given?
+    instance
+  end
+
   def self.uncolor(string)
     StringUtils.uncolor(string)
   end

spec/integration/instance_spec.rb

@@ -7,6 +7,21 @@
     expect(Rainbow.new.enabled).to eq(:yep)
   end
 
+  it 'Rainbow.new_with_enabled creates instance with different enabled state' do
+    Rainbow.enabled = :ignored
+    Rainbow.new_with_enabled(true) do |rainbow|
+      expect(rainbow.enabled).to eq(true)
+    end
+
+    rainbow = Rainbow.new_with_enabled(false) do |rainbow|
+      expect(rainbow.enabled).to eq(false)
+    end
+    expect(rainbow.enabled).to eq(false)
+
+    rainbow = Rainbow.new_with_enabled(true)
+    expect(rainbow.enabled).to eq(true)
+  end
+
   it 'tracks its own state separately from the global instance' do
     Rainbow.enabled = :yep
     rainbow = Rainbow.new

spec/integration/rainbow_spec.rb

@@ -167,4 +167,11 @@
       expect(result).to eq('hello')
     end
   end
+
+  it 'can temporarily enabled/disabled by using the block form' do
+    Rainbow.with_enabled(false) do
+      expect(Rainbow.enabled).to eq(false)
+    end
+    expect(Rainbow.enabled).to eq(true)
+  end
 end