Class: CliUtils

Inherits:
Object
  • Object
show all
Includes:
Errors
Defined in:
lib/cli_utils.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(commands_filepath = nil, config_filepath = nil, suggestions_count = nil) ⇒ CliUtils

Returns a new instance of CliUtils.



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# File 'lib/cli_utils.rb', line 21

def initialize(commands_filepath=nil, config_filepath=nil, suggestions_count=nil)
  @s_count = suggestions_count || 4

  begin
    init_commands(commands_filepath)
    init_config(config_filepath)
    parse_options

    if @command
      @eval = @commands[@command]['eval']
    end

  rescue ParseError => e
    render_error e
  rescue ArgumentError => e
    render_error e
  rescue MissingFileError => e
    render_error e
  rescue MissingCommandError => e
    err = "#{e.message} is not a command. Did you mean:\n\n"
    alts = CliUtils::top_matches(e.message, @commands.keys, @s_count).map{|m| usage(m)}.uniq.join("\n")
    $stderr.puts("#{err}#{alts}")
    exit 1
  end
end

Instance Attribute Details

#command ⇒ Object

Returns the value of attribute command.



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# File 'lib/cli_utils.rb', line 19

def command
  @command
end

#commands ⇒ Object

Returns the value of attribute commands.



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# File 'lib/cli_utils.rb', line 19

def commands
  @commands
end

#config ⇒ Object

Returns the value of attribute config.



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# File 'lib/cli_utils.rb', line 19

def config
  @config
end

#eval ⇒ Object

Returns the value of attribute eval.



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# File 'lib/cli_utils.rb', line 19

def eval
  @eval
end

#optional ⇒ Object

Returns the value of attribute optional.



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# File 'lib/cli_utils.rb', line 19

def optional
  @optional
end

#required ⇒ Object

Returns the value of attribute required.



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# File 'lib/cli_utils.rb', line 19

def required
  @required
end

Class Method Details

.levenshtein_distance(s, t) ⇒ Object 



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# File 'lib/cli_utils.rb', line 47

def self.levenshtein_distance(s, t)
  return 0 if s == t
  return t.length if s.length == 0
  return s.length if t.length == 0

  a0 = (0..t.length + 1).to_a
  a1 = []

  (0..s.length - 1).each{|i|
    a1[0] = i + 1

    (0..t.length - 1).each{|j|
      cost = (s[i] == t[j]) ? 0 : 1
      a1[j + 1] = [a1[j] + 1, a0[j + 1] + 1, a0[j] + cost].min
    }
    a0 = a1.clone
  }

  return a1[t.length]
end

.test_lev ⇒ Object 



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# File 'lib/cli_utils.rb', line 68

def self.test_lev
  ts = [ [''    , 'abc', 3],
         ['aaa' , 'aab', 1],
         ['aa'  , 'aab', 1],
         ['aaaa', 'aab', 2],
         ['aaa' , 'aaa', 0],
       ]

  ts.each_with_index{|arr,i|
    condition = levenshtein_distance(arr[0],arr[1]) == arr[2]
    puts "Test #{i}: #{(condition ? 'success' : 'failure')}"
  }
end

.top_matches(str, candidates, top = 4) ⇒ Object

TODO can return duplicates if the long and short commands are similar



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# File 'lib/cli_utils.rb', line 83

def self.top_matches(str, candidates, top=4)
  candidates.sort_by{|a| levenshtein_distance(str, a)}[0...top]
end

Instance Method Details

#dangling?(command_index, current_index, arg) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/cli_utils.rb', line 169

def dangling?(command_index, current_index, arg)
  num_req = (@commands[@command]['required'] || []).length if @command
  is_required =
    command_index &&
    (command_index + 1 + num_req) > current_index &&
    current_index > command_index

  is_value = current_index > 0 && ARGV[current_index - 1].start_with?('--')
  is_first_command = is_command?(arg) && !@command

  !(is_value || is_required || is_first_command)
end

#format_json(struct) ⇒ Object 



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# File 'lib/cli_utils.rb', line 93

def format_json(struct)
  if (@config['defaults'] || {})['pretty_print'].to_s.downcase == 'true'
    return Json.pretty_generate(struct, {'max_nesting' => 100})
  else
    return Json.generate(struct, {'max_nesting' => 100})
  end
end

#init_commands(commands_filepath) ⇒ Object

Raises:



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# File 'lib/cli_utils.rb', line 101

def init_commands(commands_filepath)
  @commands ={}
  return unless commands_filepath

  unless File.exist?(commands_filepath)
    raise MissingFileError.new("Commands File not found: #{commands_filepath}")
  end

  begin
    commands = JSON.parse(File.open(commands_filepath,'r').read)
  rescue JSON::ParserError => e
    raise ArgumentError.new("#{commands_filepath} contents is not valid JSON")
  end

  raise ArgumentError.new("#{commands_filepath} is not an array") unless commands.is_a?(Array)

  commands.each{|c|
    mb_long = c['long']
    mb_short = c['short']
    @commands[mb_long] = c if mb_long
    @commands[mb_short] = c if mb_short
  }
end

#init_config(config_filepath) ⇒ Object 



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# File 'lib/cli_utils.rb', line 201

def init_config(config_filepath)
  #TODO
  @config = {}
end

#is_command?(str) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/cli_utils.rb', line 193

def is_command?(str)
  (@commands || {}).has_key?(str)
end

#parse_options ⇒ Object 



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# File 'lib/cli_utils.rb', line 125

def parse_options
  @optional = {}
  command_index = nil
  ARGV.each_with_index {|arg, i|
    next_arg = ARGV[i + 1]

    if arg[0] == '-'
      if arg[1] == '-'
        raise ParseError.new("Missing argument to: #{arg}") unless next_arg
        @optional[arg[2..-1]] = processValue(next_arg)
      else
        @optional[tail(arg)] = true
      end
    else
      if dangling?(command_index, i, arg)
        if ARGV.find{|e| @commands.has_key?(e)}
          raise ParseError.new("Dangling command line element: #{arg}")
        else
          raise MissingCommandError.new(arg)
        end
      end

      next if @command

      if is_command?(arg)
        @command = arg
        command_index = i
        req_keys = (@commands[@command]['required'] || [])
        req_vals = ARGV[i + 1, req_keys.length]

        err_str1 = 'Missing required arguments'
        raise ParseError.new(err_str1) unless req_keys.length == req_vals.length

        err_str2 = 'Required arguments may not begin with "-"'
        raise ParseError.new(err_str2) if req_vals.map{|v| v.chr}.include?('-')

        @required = {}
        #old versions of ruby do not have a to_h array method
        req_keys.zip(req_vals).each{|(k,v)| @required[k] = processValue(v)}
      end
    end
  }
end

#processValue(val) ⇒ Object 



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# File 'lib/cli_utils.rb', line 206

def processValue(val)
  if val.start_with? '@'
    fn = tail(val)
    raise ArgumentError.new("File not found: #{fn}") unless File.exist?(fn)
    return File.open(fn,'r').read
  end
  val
end

#render_error(err) ⇒ Object 



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# File 'lib/cli_utils.rb', line 87

def render_error(err)
  $stderr.puts err.message
  $stderr.puts usage(@command) if @command
  exit 1
end

#tail(arr) ⇒ Object 



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# File 'lib/cli_utils.rb', line 197

def tail(arr)
  arr[1..-1]
end

#usage(command) ⇒ Object 



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# File 'lib/cli_utils.rb', line 182

def usage(command)
  c        = @commands[command]
  long     = c['long'] || ''
  short    = c['short'] ? "(#{c['short']})" : ''
  required = (c['required'] || []).map{|r| "<#{r}>"}.join(' ')

  optional = (c['optional'] || []).map{|o| "[#{o}#{o.start_with?('--') ? ' foo' : ''}]"}.join(' ')

  "#{long} #{short} #{required} #{optional}".gsub(/ +/,' ')
end