Sync SyntaxSuggest

```
$ tool/sync_default_gems.rb syntax_suggest
```

lib/syntax_suggest/cli.rb

@@ -0,0 +1,129 @@
+# frozen_string_literal: true
+
+require "pathname"
+require "optparse"
+
+module SyntaxSuggest
+  # All the logic of the exe/syntax_suggest CLI in one handy spot
+  #
+  #   Cli.new(argv: ["--help"]).call
+  #   Cli.new(argv: ["<path/to/file>.rb"]).call
+  #   Cli.new(argv: ["<path/to/file>.rb", "--record=tmp"]).call
+  #   Cli.new(argv: ["<path/to/file>.rb", "--terminal"]).call
+  #
+  class Cli
+    attr_accessor :options
+
+    # ARGV is Everything passed to the executable, does not include executable name
+    #
+    # All other intputs are dependency injection for testing
+    def initialize(argv:, exit_obj: Kernel, io: $stdout, env: ENV)
+      @options = {}
+      @parser = nil
+      options[:record_dir] = env["SYNTAX_SUGGEST_RECORD_DIR"]
+      options[:record_dir] = "tmp" if env["DEBUG"]
+      options[:terminal] = SyntaxSuggest::DEFAULT_VALUE
+
+      @io = io
+      @argv = argv
+      @exit_obj = exit_obj
+    end
+
+    def call
+      if @argv.empty?
+        # Display help if raw command
+        parser.parse! %w[--help]
+        return
+      else
+        # Mutates @argv
+        parse
+        return if options[:exit]
+      end
+
+      file_name = @argv.first
+      if file_name.nil?
+        @io.puts "No file given"
+        @exit_obj.exit(1)
+        return
+      end
+
+      file = Pathname(file_name)
+      if !file.exist?
+        @io.puts "file not found: #{file.expand_path} "
+        @exit_obj.exit(1)
+        return
+      end
+
+      @io.puts "Record dir: #{options[:record_dir]}" if options[:record_dir]
+
+      display = SyntaxSuggest.call(
+        io: @io,
+        source: file.read,
+        filename: file.expand_path,
+        terminal: options.fetch(:terminal, SyntaxSuggest::DEFAULT_VALUE),
+        record_dir: options[:record_dir]
+      )
+
+      if display.document_ok?
+        @exit_obj.exit(0)
+      else
+        @exit_obj.exit(1)
+      end
+    end
+
+    def parse
+      parser.parse!(@argv)
+
+      self
+    end
+
+    def parser
+      @parser ||= OptionParser.new do |opts|
+        opts.banner = <<~EOM
+          Usage: syntax_suggest <file> [options]
+
+          Parses a ruby source file and searches for syntax error(s) such as
+          unexpected `end', expecting end-of-input.
+
+          Example:
+
+            $ syntax_suggest dog.rb
+
+            # ...
+
+              ❯ 10  defdog
+              ❯ 15  end
+
+          ENV options:
+
+            SYNTAX_SUGGEST_RECORD_DIR=<dir>
+
+            Records the steps used to search for a syntax error
+            to the given directory
+
+          Options:
+        EOM
+
+        opts.version = SyntaxSuggest::VERSION
+
+        opts.on("--help", "Help - displays this message") do |v|
+          @io.puts opts
+          options[:exit] = true
+          @exit_obj.exit
+        end
+
+        opts.on("--record <dir>", "Records the steps used to search for a syntax error to the given directory") do |v|
+          options[:record_dir] = v
+        end
+
+        opts.on("--terminal", "Enable terminal highlighting") do |v|
+          options[:terminal] = true
+        end
+
+        opts.on("--no-terminal", "Disable terminal highlighting") do |v|
+          options[:terminal] = false
+        end
+      end
+    end
+  end
+end