Class: PathSpec::GitIgnoreSpec

Inherits:
RegexSpec show all
Defined in:
lib/pathspec/gitignorespec.rb

Overview

Class for parsing a .gitignore spec

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from RegexSpec

#match

Methods inherited from Spec

#match, #to_s

Constructor Details

#initialize(original_pattern) ⇒ GitIgnoreSpec

rubocop:disable Metrics/CyclomaticComplexity



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
142
143
144
145
146
147
148
149
150
151
152
153
 
# File 'lib/pathspec/gitignorespec.rb', line 8

def initialize(original_pattern) # rubocop:disable Metrics/CyclomaticComplexity
  pattern = original_pattern.strip unless original_pattern.nil?

  # A pattern starting with a hash ('#') serves as a comment
  # (neither includes nor excludes files). Escape the hash with a
  # back-slash to match a literal hash (i.e., '\#').
  if pattern.start_with?('#')
    @regex = nil
    @inclusive = nil

    # A blank pattern is a null-operation (neither includes nor
    # excludes files).
  elsif pattern.empty? # rubocop:disable Lint/DuplicateBranch
    @regex = nil
    @inclusive = nil

    # Patterns containing three or more consecutive stars are invalid and
    # will be ignored.
  elsif /\*\*\*+/.match?(pattern) # rubocop:disable Lint/DuplicateBranch
    @regex = nil
    @inclusive = nil

    # EDGE CASE: According to git check-ignore (v2.4.1)), a single '/'
    # does not match any file
  elsif pattern == '/' # rubocop:disable Lint/DuplicateBranch
    @regex = nil
    @inclusive = nil

    # We have a valid pattern!
  else
    # A pattern starting with an exclamation mark ('!') negates the
    # pattern (exclude instead of include). Escape the exclamation
    # mark with a back-slash to match a literal exclamation mark
    # (i.e., '\!').
    if pattern.start_with?('!')
      @inclusive = false
      # Remove leading exclamation mark.
      pattern = pattern[1..]
    else
      @inclusive = true
    end

    # Remove leading back-slash escape for escaped hash ('#') or
    # exclamation mark ('!').
    pattern = pattern[1..] if pattern.start_with?('\\')

    # Split pattern into segments. -1 to allow trailing slashes.
    pattern_segs = pattern.split('/', -1)

    # Normalize pattern to make processing easier.

    # A pattern beginning with a slash ('/') will only match paths
    # directly on the root directory instead of any descendant
    # paths. So, remove empty first segment to make pattern relative
    # to root.
    if pattern_segs[0].empty?
      pattern_segs.shift
    elsif pattern_segs.length == 1 ||
          pattern_segs.length == 2 && pattern_segs[-1].empty?
      # A pattern without a beginning slash ('/') will match any
      # descendant path. This is equivilent to "**/{pattern}". So,
      # prepend with double-asterisks to make pattern relative to
      # root.
      # EDGE CASE: This also holds for a single pattern with a
      # trailing slash (e.g. dir/).
      pattern_segs.insert(0, '**') if pattern_segs[0] != '**'
    end

    # A pattern ending with a slash ('/') will match all descendant
    # paths of if it is a directory but not if it is a regular file.
    # This is equivilent to "{pattern}/**". So, set last segment to
    # double asterisks to include all descendants.
    pattern_segs[-1] = '**' if pattern_segs[-1].empty? && pattern_segs.length > 1

    # Handle platforms with backslash separated paths
    path_sep = if File::SEPARATOR == '\\'
                 '\\\\'
               else
                 '/'
               end

    # Build regular expression from pattern.
    regex = '^'
    need_slash = false
    regex_end = pattern_segs.size - 1
    pattern_segs.each_index do |i|
      seg = pattern_segs[i]

      case seg
      when '**'
        # A pattern consisting solely of double-asterisks ('**')
        # will match every path.
        if i == 0 && i == regex_end
          regex.concat('.+')

          # A normalized pattern beginning with double-asterisks
          # ('**') will match any leading path segments.
        elsif i == 0
          regex.concat("(?:.+#{path_sep})?")
          need_slash = false

          # A normalized pattern ending with double-asterisks ('**')
          # will match any trailing path segments.
        elsif i == regex_end
          regex.concat("#{path_sep}.*")

          # A pattern with inner double-asterisks ('**') will match
          # multiple (or zero) inner path segments.
        else
          regex.concat("(?:#{path_sep}.+)?")
          need_slash = true
        end

        # Match single path segment.
      when '*'
        regex.concat(path_sep) if need_slash

        regex.concat("[^#{path_sep}]+")
        need_slash = true

      else
        # Match segment glob pattern.
        regex.concat(path_sep) if need_slash

        regex.concat(translate_segment_glob(seg))

        if i == regex_end && @inclusive
          # A pattern ending without a slash ('/') will match a file
          # or a directory (with paths underneath it).
          # e.g. foo matches: foo, foo/bar, foo/bar/baz, etc.
          # EDGE CASE: However, this does not hold for exclusion cases
          # according to `git check-ignore` (v2.4.1).
          regex.concat("(?:#{path_sep}.*)?")
        end

        need_slash = true
      end
    end

    regex.concat('$')
    super(regex)

    # Copy original pattern
    @pattern = original_pattern.dup
  end
end

Instance Attribute Details

#pattern ⇒ Object (readonly)

Returns the value of attribute pattern.



6
7
8
 
# File 'lib/pathspec/gitignorespec.rb', line 6

def pattern
  @pattern
end

#regex ⇒ Object (readonly)

Returns the value of attribute regex.



6
7
8
 
# File 'lib/pathspec/gitignorespec.rb', line 6

def regex
  @regex
end

Instance Method Details

#inclusive? ⇒ Boolean

Returns:

  • (Boolean) 


272
273
274
 
# File 'lib/pathspec/gitignorespec.rb', line 272

def inclusive?
  @inclusive
end

#translate_segment_glob(pattern) ⇒ Object 



155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
 
# File 'lib/pathspec/gitignorespec.rb', line 155

def translate_segment_glob(pattern)
  # Translates the glob pattern to a regular expression. This is used in
  # the constructor to translate a path segment glob pattern to its
  # corresponding regular expression.
  #
  # *pattern* (``str``) is the glob pattern.
  #
  # Returns the regular expression (``str``).
  #
  # NOTE: This is derived from `fnmatch.translate()` and is similar to
  # the POSIX function `fnmatch()` with the `FNM_PATHNAME` flag set.

  escape = false
  regex = ''
  i = 0

  while i < pattern.size
    # Get next character.
    char = pattern[i].chr
    i += 1

    # Escape the character.
    if escape
      escape = false
      regex += Regexp.escape(char)

      # Escape character, escape next character.
    elsif char == '\\'
      escape = true

      # Multi-character wildcard. Match any string (except slashes),
      # including an empty string.
    elsif char == '*'
      regex += '[^/]*'

      # Single-character wildcard. Match any single character (except
      # a slash).
    elsif char == '?'
      regex += '[^/]'

      # Braket expression wildcard. Except for the beginning
      # exclamation mark, the whole braket expression can be used
      # directly as regex but we have to find where the expression
      # ends.
      # - "[][!]" matchs ']', '[' and '!'.
      # - "[]-]" matchs ']' and '-'.
      # - "[!]a-]" matchs any character except ']', 'a' and '-'.
    elsif char == '['
      j = i
      # Pass brack expression negation.
      j += 1 if j < pattern.size && pattern[j].chr == '!'

      # Pass first closing braket if it is at the beginning of the
      # expression.
      j += 1 if j < pattern.size && pattern[j].chr == ']'

      # Find closing braket. Stop once we reach the end or find it.
      j += 1 while j < pattern.size && pattern[j].chr != ']'

      if j < pattern.size
        expr = '['

        # Braket expression needs to be negated.
        case pattern[i].chr
        when '!'
          expr += '^'
          i += 1

          # POSIX declares that the regex braket expression negation
          # "[^...]" is undefined in a glob pattern. Python's
          # `fnmatch.translate()` escapes the caret ('^') as a
          # literal. To maintain consistency with undefined behavior,
          # I am escaping the '^' as well.
        when '^'
          expr += '\\^'
          i += 1
        end

        # Escape brackets contained within pattern
        if pattern[i].chr == ']' && i != j
          expr += '\]'
          i += 1
        end

        # Build regex braket expression. Escape slashes so they are
        # treated as literal slashes by regex as defined by POSIX.
        expr += pattern[i..j].sub('\\', '\\\\')

        # Add regex braket expression to regex result.
        regex += expr

        # Found end of braket expression. Increment j to be one past
        # the closing braket:
        #
        #  [...]
        #   ^   ^
        #   i   j
        #
        j += 1
        # Set i to one past the closing braket.
        i = j

        # Failed to find closing braket, treat opening braket as a
        # braket literal instead of as an expression.
      else
        regex += '\['
      end

      # Regular character, escape it for regex.
    else
      regex << Regexp.escape(char)
    end
  end

  regex
end