Add :eta_time token to display the estimated time of day at completion

CHANGELOG.md

@@ -9,6 +9,7 @@
 * Add Multi#done? to check if all bar are stopped or finished
 * Add indeterminate progress support when no total is given
 * Add :bar_format option to allow selecting preconfigured bar displays
+* Add :eta_time format token to display the estimated time of day at completion
 
 ### Changed
 * Change Multi#stopped? to check that all bars are stopped

README.md

@@ -573,6 +573,7 @@ These are the tokens that are currently supported:
 * `:percent` the completion percentage
 * `:elapsed` the elapsed time in seconds
 * `:eta` the estimated time to completion in seconds
+* `:eta_time` the estimated time of day at completion
 * `:rate` the current rate of progression per second
 * `:byte_rate` the current rate of progression in bytes per second
 * `:mean_rate` the averaged rate of progression per second

lib/tty/progressbar/formatter/estimated_time.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+module TTY
+  class ProgressBar
+    # Used by {Pipeline} to foramt :eta_time token
+    #
+    # @api private
+    class EstimatedTimeFormatter
+      include TTY::ProgressBar::Formatter[/:eta_time/.freeze]
+
+      # Format :eta_time token
+      #
+      # @param [String] value
+      #   the value to format
+      #
+      # @api public
+      def format(value)
+        if @progress.indeterminate?
+          return value.gsub(matcher, "--:--:--")
+        end
+
+        elapsed   = Time.now - @progress.start_at
+        estimated = (elapsed / @progress.ratio).to_f - elapsed
+        estimated = (estimated.infinite? || estimated < 0) ? 0.0 : estimated
+
+        time_format = if estimated >= 86_400 # longer than a day
+                        "%Y-%m-%d %H:%M:%S"
+                      else
+                        "%H:%M:%S"
+                      end
+        completion_time = Time.now + estimated
+        eta_time = completion_time.strftime(time_format)
+        value.gsub(matcher, eta_time)
+      end
+    end # EstimatedTimeFormatter
+  end # ProgressBar
+end # TTY

lib/tty/progressbar/formatters.rb

@@ -9,6 +9,7 @@
 require_relative "formatter/current_byte"
 require_relative "formatter/elapsed"
 require_relative "formatter/estimated"
+require_relative "formatter/estimated_time"
 require_relative "formatter/percent"
 require_relative "formatter/rate"
 require_relative "formatter/byte_rate"
@@ -37,6 +38,7 @@ def load(progress)
         @pipeline.use TTY::ProgressBar::TotalFormatter.new(progress)
         @pipeline.use TTY::ProgressBar::TotalByteFormatter.new(progress)
         @pipeline.use TTY::ProgressBar::ElapsedFormatter.new(progress)
+        @pipeline.use TTY::ProgressBar::EstimatedTimeFormatter.new(progress)
         @pipeline.use TTY::ProgressBar::EstimatedFormatter.new(progress)
         @pipeline.use TTY::ProgressBar::PercentFormatter.new(progress)
         @pipeline.use TTY::ProgressBar::ByteFormatter.new(progress)

spec/unit/formatter/estimated_time_spec.rb

@@ -0,0 +1,71 @@
+# frozen_string_literal: true
+
+RSpec.describe TTY::ProgressBar, ":eta_time token" do
+  let(:output) { StringIO.new }
+
+  it "displays estimated completion time of day" do
+    time_now = Time.local(2020, 1, 5, 12, 0, 0)
+    Timecop.freeze(time_now)
+    bar = described_class.new(" :eta_time", output: output, total: 5)
+
+    5.times do |sec|
+      time_now = Time.local(2020, 1, 5, 12, 0, sec)
+      Timecop.freeze(time_now)
+      bar.advance
+    end
+
+    output.rewind
+    expect(output.read).to eq([
+      "\e[1G 12:00:00",
+      "\e[1G 12:00:02",
+      "\e[1G 12:00:03",
+      "\e[1G 12:00:03",
+      "\e[1G 12:00:04\n"
+    ].join)
+    Timecop.return
+  end
+
+  it "displays estimated completion time of day with date after 24 hours" do
+    time_now = Time.local(2020, 1, 5, 12, 0, 0)
+    Timecop.freeze(time_now)
+    bar = described_class.new(" :eta_time", output: output, total: 5)
+
+    2.times do |day|
+      time_now = Time.local(2020, 1, day + 6, 12, 0, 0)
+      Timecop.freeze(time_now)
+      bar.advance
+    end
+
+    output.rewind
+    expect(output.read).to eq([
+      "\e[1G 12:00:00",
+      "\e[1G 2020-01-09 00:00:00",
+    ].join)
+    Timecop.return
+  end
+
+  it "displays unknown estimated completion time of day as --:--:--" do
+    time_now = Time.local(2020, 1, 5, 12, 0, 0)
+    Timecop.freeze(time_now)
+    bar = described_class.new(" :eta_time", output: output, total: nil)
+
+    3.times { bar.advance }
+    bar.update(total: 5)
+
+    2.times do |sec|
+      time_now = Time.local(2020, 1, 5, 12, 0, sec)
+      Timecop.freeze(time_now)
+      bar.advance
+    end
+
+    output.rewind
+    expect(output.read).to eq([
+      "\e[1G --:--:--",
+      "\e[1G --:--:--",
+      "\e[1G --:--:--",
+      "\e[1G 12:00:00",
+      "\e[1G 12:00:01\n"
+    ].join)
+    Timecop.return
+  end
+end