Class: RuboCop::Cop::StatsD::PositionalArguments

Inherits:
Base
  • Object
show all
Extended by:
AutoCorrector
Includes:
RuboCop::Cop::StatsD
Defined in:
lib/statsd/instrument/rubocop/positional_arguments.rb

Overview

This Rubocop will check for using the StatsD metric methods (e.g. StatsD.instrument) for positional argument usage, which is deprecated.

Use the following Rubocop invocation to check your project's codebase:

rubocop --require `bundle show statsd-instrument`/lib/statsd/instrument/rubocop.rb \
  --only StatsD/PositionalArguments

This cop can autocorrect some offenses it finds, but not all of them.

Constant Summary collapse

MSG = 
"Use keyword arguments for StatsD calls"
POSITIONAL_ARGUMENT_TYPES = 
Set[:int, :float, :nil]
UNKNOWN_ARGUMENT_TYPES = 
Set[:send, :const, :lvar, :splat]
REFUSED_ARGUMENT_TYPES = 
POSITIONAL_ARGUMENT_TYPES | UNKNOWN_ARGUMENT_TYPES
KEYWORD_ARGUMENT_TYPES = 
Set[:hash]
BLOCK_ARGUMENT_TYPES = 
Set[:block_pass]
ACCEPTED_ARGUMENT_TYPES = 
KEYWORD_ARGUMENT_TYPES | BLOCK_ARGUMENT_TYPES

Constants included from RuboCop::Cop::StatsD

METAPROGRAMMING_METHODS, METRIC_METHODS, SINGLETON_CONFIGURATION_METHODS

Instance Method Summary collapse

Instance Method Details

#autocorrect(corrector, node) ⇒ Object 



46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
 
# File 'lib/statsd/instrument/rubocop/positional_arguments.rb', line 46

def autocorrect(corrector, node)
  positional_arguments = if node.arguments.last.type == :block_pass
    node.arguments[2...node.arguments.length - 1]
  else
    node.arguments[2...node.arguments.length]
  end

  case positional_arguments[0].type
  when *UNKNOWN_ARGUMENT_TYPES
    # We don't know whether the method returns a hash, in which case it would be interpreted
    # as keyword arguments. In this case, the fix would be to add a keyword splat:
    #
    # `StatsD.instrument('foo', 1, method_call)`
    # => `StatsD.instrument('foo', 1, **method_call)`
    #
    # However, it's also possible this method returns a sample rate, in which case the fix
    # above will not do the right thing.
    #
    # `StatsD.instrument('foo', 1, SAMPLE_RATE_CONSTANT)`
    # => `StatsD.instrument('foo', 1, sample_rate: SAMPLE_RATE_CONSTANT)`
    #
    # Because of this, we will not auto-correct and let the user fix the issue manually.
    nil

  when *POSITIONAL_ARGUMENT_TYPES
    value_argument = node.arguments[1]
    from = value_argument.source_range.end_pos
    to = positional_arguments.last.source_range.end_pos
    range = Parser::Source::Range.new(node.source_range.source_buffer, from, to)
    corrector.remove(range)

    keyword_arguments = []
    sample_rate = positional_arguments[0]
    if sample_rate && sample_rate.type != :nil
      keyword_arguments << "sample_rate: #{sample_rate.source}"
    end

    tags = positional_arguments[1]
    if tags && tags.type != :nil
      keyword_arguments << if tags.type == :hash && tags.source[0] != "{"
        "tags: { #{tags.source} }"
      else
        "tags: #{tags.source}"
      end
    end

    unless keyword_arguments.empty?
      corrector.insert_after(value_argument.source_range, ", #{keyword_arguments.join(", ")}")
    end

  end
end

#on_send(node) ⇒ Object 



31
32
33
34
35
36
37
38
39
40
41
42
43
44
 
# File 'lib/statsd/instrument/rubocop/positional_arguments.rb', line 31

def on_send(node)
  if metric_method?(node) && node.arguments.length >= 3
    case node.arguments[2].type
    when *REFUSED_ARGUMENT_TYPES
      add_offense(node) do |corrector|
        autocorrect(corrector, node)
      end
    when *ACCEPTED_ARGUMENT_TYPES
      nil
    else
      $stderr.puts "[StatsD/PositionalArguments] Unhandled argument type: #{node.arguments[2].type.inspect}"
    end
  end
end