Remove: smoothing Option

Why This Change Is Necessary
========================================================================

The plan is to allow different types of projectors to be used by the gem
at some point and not all of those projectors are going to need the
option to smooth, so instead we will change the configuration to allow
for each projector to have their own configuration.

What These Changes Do To Address the Issue
========================================================================

We add a deprecation warning for anyone using `smoothing` as an option
and also add the new approach.

The new approach will be instead of passing this:

```ruby
ProgressBar.create(smoothing: 0.1)
```

You would pass:

```ruby
ProgressBar.create(projector: { smoothing: 0.1 })
```

Side Effects Caused By This Change
========================================================================

Additional warnings for anyone using `smoothing`.

Author: jfelchner

lib/ruby-progressbar/base.rb

@@ -17,6 +17,22 @@ class   ProgressBar
 class   Base
   extend Forwardable
 
+  # rubocop:disable Layout/HeredocIndentation
+  SMOOTHING_DEPRECATION_WARNING = <<-HEREDOC.tr("\n", ' ')
+WARNING: Passing the 'smoothing' option is deprecated  and will be removed
+in version 2.0. Please pass { projector: { type: 'smoothing', strength: 0.x }}.
+For more information on why this change is happening,  visit
+https://github.com/jfelchner/ruby-progressbar/wiki/Upgrading
+  HEREDOC
+
+  RUNNING_AVERAGE_RATE_DEPRECATION_WARNING = <<-HEREDOC.tr("\n", ' ')
+WARNING: Passing the 'running_average_rate' option is deprecated  and will be removed
+in version 2.0. Please pass { projector: { type: 'smoothing', strength: 0.x }}.
+For more information on why this change is happening,  visit
+https://github.com/jfelchner/ruby-progressbar/wiki/Upgrading
+  HEREDOC
+  # rubocop:enable Layout/HeredocIndentation
+
   def_delegators :output,
                  :clear,
                  :log,
@@ -32,7 +48,20 @@ def initialize(options = {}) # rubocop:disable Metrics/AbcSize
     self.finished     = false
 
     self.timer        = Timer.new(options)
-    self.projector    = Calculators::SmoothedAverage.new(:strength => options[:smoothing])
+    projector_opts    = if options[:projector]
+                          options[:projector]
+                        elsif options[:smoothing]
+                          warn SMOOTHING_DEPRECATION_WARNING
+
+                          { :strength => options[:smoothing] }
+                        elsif options[:running_average_rate]
+                          warn RUNNING_AVERAGE_RATE_DEPRECATION_WARNING
+
+                          { :strength => options[:smoothing] }
+                        else
+                          {}
+                        end
+    self.projector    = Calculators::SmoothedAverage.new(projector_opts)
     self.progressable = Progress.new(options.merge(:projector => projector))
 
     options = options.merge(:progress  => progressable,

spec/lib/ruby-progressbar/base_spec.rb

@@ -232,7 +232,7 @@ class    ProgressBar
       Timecop.freeze(::Time.utc(2020, 1, 1, 0, 0, 0))
 
       progressbar = ProgressBar::Base.new(:output    => output,
-                                          :smoothing => 0.0,
+                                          :projector => { :strength => 0.0 },
                                           :total     => 100,
                                           :format    => '%l')
 
@@ -251,7 +251,7 @@ class    ProgressBar
       Timecop.freeze(::Time.utc(2020, 1, 1, 0, 0, 0))
 
       progressbar = ProgressBar::Base.new(:output    => output,
-                                          :smoothing => 0.0,
+                                          :projector => { :strength => 0.0 },
                                           :total     => 100,
                                           :format    => '%l')
 
@@ -275,6 +275,32 @@ class    ProgressBar
         not_to raise_error
     end
 
+    # rubocop:disable RSpec/AnyInstance
+    it 'displays a warning if the user passes the deprecated "smoothing" option but ' \
+       'still processes it' do
+      expect_any_instance_of(ProgressBar::Base).
+        to receive(:warn).
+        with(include("WARNING: Passing the 'smoothing' option is deprecated"))
+
+      Timecop.freeze(::Time.utc(2020, 1, 1, 0, 0, 0))
+
+      progressbar = ProgressBar::Base.new(:output    => output,
+                                          :smoothing => 0.0,
+                                          :total     => 100,
+                                          :format    => '%l')
+
+      progressbar.progress += 50
+
+      Timecop.freeze(::Time.utc(2020, 1, 1, 0, 30, 0))
+
+      progressbar.finish
+
+      Timecop.return
+
+      expect(progressbar.to_s).to eql '00:30:00'
+    end
+    # rubocop:enable RSpec/AnyInstance
+
     it 'appends proper ending to string for non-TTY devices' do
       progressbar = ProgressBar::Base.new(:output => non_tty_output)
 

spec/lib/ruby-progressbar/format/formatter_spec.rb

@@ -138,7 +138,7 @@ module   Format
     end
 
     it 'is the estimated time remaining when called after the bar is started' do
-      progressbar = ProgressBar::Base.new(:smoothing => 0.0)
+      progressbar = ProgressBar::Base.new(:projector => { :strength => 0.0 })
 
       Timecop.freeze(to_the_past) do
         progressbar.start
@@ -150,7 +150,7 @@ module   Format
 
     it 'is "??:??:??" when it could take 100 hours or longer to finish' do
       progressbar = ProgressBar::Base.new(:total     => 100,
-                                          :smoothing => 0.0)
+                                          :projector => { :strength => 0.0 })
 
       Timecop.freeze(one_hundred_hours_ago) do
         progressbar.start
@@ -207,7 +207,7 @@ module   Format
       progressbar = nil
 
       Timecop.freeze(::Time.utc(2020, 1, 1, 0, 0, 0)) do
-        progressbar = ProgressBar::Base.new(:smoothing => 0.0)
+        progressbar = ProgressBar::Base.new(:projector => { :strength => 0.0 })
 
         progressbar.start
         progressbar.progress = 50
@@ -262,7 +262,7 @@ module   Format
     end
 
     it 'is the estimated time remaining when called after the bar is started' do
-      progressbar = ProgressBar::Base.new(:smoothing => 0.0)
+      progressbar = ProgressBar::Base.new(:projector => { :strength => 0.0 })
 
       Timecop.freeze(to_the_past) do
         progressbar.start
@@ -288,7 +288,7 @@ module   Format
 
     it 'is "> 4 Days" when it could take 100 hours or longer to finish' do
       progressbar = ProgressBar::Base.new(:total     => 100,
-                                          :smoothing => 0.0)
+                                          :projector => { :strength => 0.0 })
 
       Timecop.freeze(one_hundred_hours_ago) do
         progressbar.start
@@ -328,7 +328,7 @@ module   Format
     end
 
     it 'is the estimated time remaining when called after the bar is started' do
-      progressbar = ProgressBar::Base.new(:smoothing => 0.0)
+      progressbar = ProgressBar::Base.new(:projector => { :strength => 0.0 })
 
       Timecop.freeze(to_the_past) do
         progressbar.start
@@ -340,7 +340,7 @@ module   Format
 
     it 'is the exact estimated time when it could take 100 hours or longer to finish' do
       progressbar = ProgressBar::Base.new(:total     => 100,
-                                          :smoothing => 0.0)
+                                          :projector => { :strength => 0.0 })
 
       Timecop.freeze(one_hundred_hours_ago) do
         progressbar.start