Suggest check_concurrency when status reports an incorrect quantity

lib/procodile/status_cli_output.rb

@@ -36,6 +36,9 @@ def print_header
         for message in @status['messages']
           puts "\e[31m * #{Message.parse(message)}\e[0m"
         end
+        if @status['messages'].any? { |message| message['type'] == 'incorrect_quantity' }
+          puts "\e[33m   Run `procodile check_concurrency` to start the missing process(es).\e[0m"
+        end
       end
     end
 

spec/specs/status_cli_output_spec.rb

@@ -0,0 +1,58 @@
+require 'spec_helper'
+require 'procodile/status_cli_output'
+
+describe Procodile::StatusCLIOutput do
+  def status_with(messages)
+    {
+      'version' => '1.0.27',
+      'root' => '/apps/example',
+      'supervisor' => {'pid' => 100, 'started_at' => nil},
+      'environment_variables' => {},
+      'messages' => messages
+    }
+  end
+
+  let(:incorrect_quantity) do
+    {'type' => 'incorrect_quantity', 'process' => 'worker', 'current' => 23, 'desired' => 25}
+  end
+
+  let(:not_running) do
+    {'type' => 'not_running', 'instance' => 'worker.1', 'status' => 'Failed'}
+  end
+
+  context "when a process is below its configured quantity" do
+    subject(:cli) { described_class.new(status_with([incorrect_quantity])) }
+
+    it "still prints the underlying message" do
+      expect { cli.print_header }.to output(/worker only has 23 instances \(should have 25\)/).to_stdout
+    end
+
+    it "suggests check_concurrency as the remedy" do
+      expect { cli.print_header }.to output(/procodile check_concurrency/).to_stdout
+    end
+  end
+
+  context "when the only messages are unrelated to quantity" do
+    subject(:cli) { described_class.new(status_with([not_running])) }
+
+    it "does not suggest check_concurrency" do
+      expect { cli.print_header }.to_not output(/check_concurrency/).to_stdout
+    end
+  end
+
+  context "when there are no messages at all" do
+    subject(:cli) { described_class.new(status_with([])) }
+
+    it "does not suggest check_concurrency" do
+      expect { cli.print_header }.to_not output(/check_concurrency/).to_stdout
+    end
+  end
+
+  context "when quantity and other messages are both present" do
+    subject(:cli) { described_class.new(status_with([not_running, incorrect_quantity])) }
+
+    it "suggests check_concurrency only once" do
+      expect { cli.print_header }.to output(/check_concurrency/).to_stdout
+    end
+  end
+end