Change to prevent resizing an indeterminate bar with unicode characters

lib/tty/progressbar/formatter/bar.rb

@@ -39,9 +39,20 @@ def call(value)
       # @api private
       def format_indeterminate(value, width)
         buffer = []
-        width -= @progress.unknown.size
-        complete = (width * @progress.ratio).round
-        incomplete = width - complete
+        possible_width = width
+        unknown_char_length    = ProgressBar.display_columns(@progress.unknown)
+        complete_char_length   = ProgressBar.display_columns(@progress.complete)
+        incomplete_char_length = ProgressBar.display_columns(@progress.incomplete)
+        head_char_length       = ProgressBar.display_columns(@progress.head)
+
+        possible_width -= unknown_char_length
+        max_char_length = [complete_char_length, incomplete_char_length,
+                           head_char_length].max
+        # figure out how many unicode chars would fit normally
+        # when the bar has total to prevent resizing
+        possible_width = (possible_width / max_char_length) * max_char_length
+        complete = (possible_width * @progress.ratio).round
+        incomplete = possible_width - complete
 
         buffer << " " * complete
         buffer << @progress.unknown

spec/unit/formatter/bar_spec.rb

@@ -155,5 +155,30 @@
         "\e[1G[本本本> ]\n"
       ].join)
     end
+
+    it "unknown with ascii and unicode chars" do
+      progress = TTY::ProgressBar.new("[:bar]", output: output, incomplete: rem,
+                                                complete: done, head: ">",
+                                                unknown: "<#{done}>",
+                                                total: nil, width: 9)
+
+      5.times { progress.advance }
+      progress.update(total: 10)
+      5.times { progress.advance }
+      output.rewind
+
+      expect(output.read).to eq([
+        "\e[1G[<本>    ]",
+        "\e[1G[<本>    ]",
+        "\e[1G[<本>    ]",
+        "\e[1G[<本>    ]",
+        "\e[1G[<本>    ]",
+        "\e[1G[本> 〜〜]",
+        "\e[1G[本本> 〜]",
+        "\e[1G[本本> 〜]",
+        "\e[1G[本本本> ]",
+        "\e[1G[本本本> ]\n",
+      ].join)
+    end
   end
 end