Add test to check cli help and messages

spec/tapioca/cli/help_spec.rb

@@ -0,0 +1,38 @@
+# typed: strict
+# frozen_string_literal: true
+
+require "spec_helper"
+
+module Tapioca
+  class HelpSpec < SpecWithProject
+    describe("cli::help") do
+      before(:all) do
+        project.bundle_install
+      end
+
+      it "must display the help when passing --help" do
+        result = @project.tapioca("--help")
+        stdout_lines = result.out.strip.split("\n")
+        assert_equal("Commands:", stdout_lines.first)
+        assert_empty_stderr(result)
+        assert_success_status(result)
+      end
+
+      it "must display the help when passing -h" do
+        result = @project.tapioca("-h")
+        stdout_lines = result.out.strip.split("\n")
+        assert_equal("Commands:", stdout_lines.first)
+        assert_empty_stderr(result)
+        assert_success_status(result)
+      end
+
+      it "must begin every command description of help text with a capital letter" do
+        result = @project.tapioca("--help")
+        stdout_lines = result.out.strip.split("\n")
+        assert_equal(stdout_lines.reject { / # [a-z]/.match?(_1) }.size, stdout_lines.size)
+        assert_empty_stderr(result)
+        assert_success_status(result)
+      end
+    end
+  end
+end