aboutsummaryrefslogtreecommitdiffstats
path: root/railties/lib/rails/source_annotation_extractor.rb
blob: d6cde227c5482d3de975b4bee1ce232aef3f1820 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
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
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
# frozen_string_literal: true

# Implements the logic behind the rake tasks for annotations like
#
#   rails notes
#   rails notes:optimize
#
# and friends. See <tt>rails -T notes</tt> and <tt>railties/lib/rails/tasks/annotations.rake</tt>.
#
# Annotation objects are triplets <tt>:line</tt>, <tt>:tag</tt>, <tt>:text</tt> that
# represent the line where the annotation lives, its tag, and its text. Note
# the filename is not stored.
#
# Annotations are looked for in comments and modulus whitespace they have to
# start with the tag optionally followed by a colon. Everything up to the end
# of the line (or closing ERB comment tag) is considered to be their text.
class SourceAnnotationExtractor
  Annotation = Struct.new(:line, :tag, :text) do
    def self.directories
      @@directories ||= %w(app config db lib test) + (ENV["SOURCE_ANNOTATION_DIRECTORIES"] || "").split(",")
    end

    # Registers additional directories to be included
    #  SourceAnnotationExtractor::Annotation.register_directories("spec","another")
    def self.register_directories(*dirs)
      directories.push(*dirs)
    end

    def self.extensions
      @@extensions ||= {}
    end

    # Registers new Annotations File Extensions
    #   SourceAnnotationExtractor::Annotation.register_extensions("css", "scss", "sass", "less", "js") { |tag| /\/\/\s*(#{tag}):?\s*(.*)$/ }
    def self.register_extensions(*exts, &block)
      extensions[/\.(#{exts.join("|")})$/] = block
    end

    register_extensions("builder", "rb", "rake", "yml", "yaml", "ruby") { |tag| /#\s*(#{tag}):?\s*(.*)$/ }
    register_extensions("css", "js") { |tag| /\/\/\s*(#{tag}):?\s*(.*)$/ }
    register_extensions("erb") { |tag| /<%\s*#\s*(#{tag}):?\s*(.*?)\s*%>/ }

    # Returns a representation of the annotation that looks like this:
    #
    #   [126] [TODO] This algorithm is simple and clearly correct, make it faster.
    #
    # If +options+ has a flag <tt>:tag</tt> the tag is shown as in the example above.
    # Otherwise the string contains just line and text.
    def to_s(options = {})
      s = "[#{line.to_s.rjust(options[:indent])}] ".dup
      s << "[#{tag}] " if options[:tag]
      s << text
    end
  end

  # Prints all annotations with tag +tag+ under the root directories +app+,
  # +config+, +db+, +lib+, and +test+ (recursively).
  #
  # Additional directories may be added using a comma-delimited list set using
  # <tt>ENV['SOURCE_ANNOTATION_DIRECTORIES']</tt>.
  #
  # Directories may also be explicitly set using the <tt>:dirs</tt> key in +options+.
  #
  #   SourceAnnotationExtractor.enumerate 'TODO|FIXME', dirs: %w(app lib), tag: true
  #
  # If +options+ has a <tt>:tag</tt> flag, it will be passed to each annotation's +to_s+.
  #
  # See <tt>#find_in</tt> for a list of file extensions that will be taken into account.
  #
  # This class method is the single entry point for the rake tasks.
  def self.enumerate(tag, options = {})
    extractor = new(tag)
    dirs = options.delete(:dirs) || Annotation.directories
    extractor.display(extractor.find(dirs), options)
  end

  attr_reader :tag

  def initialize(tag)
    @tag = tag
  end

  # Returns a hash that maps filenames under +dirs+ (recursively) to arrays
  # with their annotations.
  def find(dirs)
    dirs.inject({}) { |h, dir| h.update(find_in(dir)) }
  end

  # Returns a hash that maps filenames under +dir+ (recursively) to arrays
  # with their annotations. Only files with annotations are included. Files
  # with extension +.builder+, +.rb+, +.rake+, +.yml+, +.yaml+, +.ruby+,
  # +.css+, +.js+ and +.erb+ are taken into account.
  def find_in(dir)
    results = {}

    Dir.glob("#{dir}/*") do |item|
      next if File.basename(item)[0] == ?.

      if File.directory?(item)
        results.update(find_in(item))
      else
        extension = Annotation.extensions.detect do |regexp, _block|
          regexp.match(item)
        end

        if extension
          pattern = extension.last.call(tag)
          results.update(extract_annotations_from(item, pattern)) if pattern
        end
      end
    end

    results
  end

  # If +file+ is the filename of a file that contains annotations this method returns
  # a hash with a single entry that maps +file+ to an array of its annotations.
  # Otherwise it returns an empty hash.
  def extract_annotations_from(file, pattern)
    lineno = 0
    result = File.readlines(file, encoding: Encoding::BINARY).inject([]) do |list, line|
      lineno += 1
      next list unless line =~ pattern
      list << Annotation.new(lineno, $1, $2)
    end
    result.empty? ? {} : { file => result }
  end

  # Prints the mapping from filenames to annotations in +results+ ordered by filename.
  # The +options+ hash is passed to each annotation's +to_s+.
  def display(results, options = {})
    options[:indent] = results.flat_map { |f, a| a.map(&:line) }.max.to_s.size
    results.keys.sort.each do |file|
      puts "#{file}:"
      results[file].each do |note|
        puts "  * #{note.to_s(options)}"
      end
      puts
    end
  end
end