Class: Rack::Lint

Inherits:
Object
  • Object
show all
Defined in:
lib/rack/lint.rb

Overview

Rack::Lint validates your application and the requests and responses according to the Rack spec.

Defined Under Namespace

Modules: Assertion Classes: ErrorWrapper, HijackWrapper, InputWrapper, LintError

Instance Method Summary collapse

Constructor Details

#initialize(app) ⇒ Lint

Returns a new instance of Lint.


10
11
12
13
# File 'lib/rack/lint.rb', line 10

def initialize(app)
  @app = app
  @content_length = nil
end

Instance Method Details

#_call(env) ⇒ Object

Raises:


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
# File 'lib/rack/lint.rb', line 42

def _call(env)
  @env = env
  ## It takes exactly one argument, the *environment*
  raise LintError, "No env given" unless env
  check_env env

  env[RACK_INPUT] = InputWrapper.new(env[RACK_INPUT])
  env[RACK_ERRORS] = ErrorWrapper.new(env[RACK_ERRORS])

  ## and returns an Array of exactly three values:
  ary = @app.call(env)
  raise LintError, "response is not an Array, but #{ary.class}" unless ary.kind_of? Array
  raise LintError, "response array has #{ary.size} elements instead of 3" unless ary.size == 3

  status, headers, @body = ary
  ## The *status*,
  check_status status
  ## the *headers*,
  check_headers headers

  hijack_proc = check_hijack_response headers, env
  if hijack_proc && headers.is_a?(Hash)
    headers[RACK_HIJACK] = hijack_proc
  end

  ## and the *body*.
  check_content_type status, headers
  check_content_length status, headers
  @head_request = env[REQUEST_METHOD] == HEAD

  @lint = (env['rack.lint'] ||= []) << self

  if (env['rack.lint.body_iteration'] ||= 0) > 0
    raise LintError, "Middleware must not call #each directly"
  end

  [status, headers, self]
end

#call(env = nil) ⇒ Object

A Rack application is a Ruby object (not a class) that responds to call.


38
39
40
# File 'lib/rack/lint.rb', line 38

def call(env = nil)
  dup._call(env)
end

#check_content_length(status, headers) ⇒ Object

The Content-Length


712
713
714
715
716
717
718
719
720
721
722
723
# File 'lib/rack/lint.rb', line 712

def check_content_length(status, headers)
  headers.each { |key, value|
    if key.downcase == 'content-length'
      ## There must not be a <tt>Content-Length</tt> header when the
      ## +Status+ is 1xx, 204 or 304.
      if Rack::Utils::STATUS_WITH_NO_ENTITY_BODY.key? status.to_i
        raise LintError, "Content-Length header found in #{status} response, not allowed"
      end
      @content_length = value
    end
  }
end

#check_content_type(status, headers) ⇒ Object

The Content-Type


698
699
700
701
702
703
704
705
706
707
708
709
# File 'lib/rack/lint.rb', line 698

def check_content_type(status, headers)
  headers.each { |key, value|
    ## There must not be a <tt>Content-Type</tt>, when the +Status+ is 1xx,
    ## 204 or 304.
    if key.downcase == "content-type"
      if Rack::Utils::STATUS_WITH_NO_ENTITY_BODY.key? status.to_i
        raise LintError, "Content-Type header found in #{status} response, not allowed"
      end
      return
    end
  }
end

#check_env(env) ⇒ Object

The Environment

Raises:


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
154
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
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
# File 'lib/rack/lint.rb', line 82

def check_env(env)
  ## The environment must be an unfrozen instance of Hash that includes
  ## CGI-like headers.  The application is free to modify the
  ## environment.
  raise LintError, "env #{env.inspect} is not a Hash, but #{env.class}" unless env.kind_of? Hash
  raise LintError, "env should not be frozen, but is" if env.frozen?

  ##
  ## The environment is required to include these variables
  ## (adopted from PEP333), except when they'd be empty, but see
  ## below.

  ## <tt>REQUEST_METHOD</tt>:: The HTTP request method, such as
  ##                           "GET" or "POST". This cannot ever
  ##                           be an empty string, and so is
  ##                           always required.

  ## <tt>SCRIPT_NAME</tt>:: The initial portion of the request
  ##                        URL's "path" that corresponds to the
  ##                        application object, so that the
  ##                        application knows its virtual
  ##                        "location". This may be an empty
  ##                        string, if the application corresponds
  ##                        to the "root" of the server.

  ## <tt>PATH_INFO</tt>:: The remainder of the request URL's
  ##                      "path", designating the virtual
  ##                      "location" of the request's target
  ##                      within the application. This may be an
  ##                      empty string, if the request URL targets
  ##                      the application root and does not have a
  ##                      trailing slash. This value may be
  ##                      percent-encoded when originating from
  ##                      a URL.

  ## <tt>QUERY_STRING</tt>:: The portion of the request URL that
  ##                         follows the <tt>?</tt>, if any. May be
  ##                         empty, but is always required!

  ## <tt>SERVER_NAME</tt>:: When combined with <tt>SCRIPT_NAME</tt> and
  ##                        <tt>PATH_INFO</tt>, these variables can be
  ##                        used to complete the URL. Note, however,
  ##                        that <tt>HTTP_HOST</tt>, if present,
  ##                        should be used in preference to
  ##                        <tt>SERVER_NAME</tt> for reconstructing
  ##                        the request URL.
  ##                        <tt>SERVER_NAME</tt> can never be an empty
  ##                        string, and so is always required.

  ## <tt>SERVER_PORT</tt>:: An optional +Integer+ which is the port the
  ##                        server is running on. Should be specified if
  ##                        the server is running on a non-standard port.

  ## <tt>HTTP_</tt> Variables:: Variables corresponding to the
  ##                            client-supplied HTTP request
  ##                            headers (i.e., variables whose
  ##                            names begin with <tt>HTTP_</tt>). The
  ##                            presence or absence of these
  ##                            variables should correspond with
  ##                            the presence or absence of the
  ##                            appropriate HTTP header in the
  ##                            request. See
  ##                            {RFC3875 section 4.1.18}[https://tools.ietf.org/html/rfc3875#section-4.1.18]
  ##                            for specific behavior.

  ## In addition to this, the Rack environment must include these
  ## Rack-specific variables:

  ## <tt>rack.version</tt>:: The Array representing this version of Rack
  ##                         See Rack::VERSION, that corresponds to
  ##                         the version of this SPEC.

  ## <tt>rack.url_scheme</tt>:: +http+ or +https+, depending on the
  ##                            request URL.

  ## <tt>rack.input</tt>:: See below, the input stream.

  ## <tt>rack.errors</tt>:: See below, the error stream.

  ## <tt>rack.multithread</tt>:: true if the application object may be
  ##                             simultaneously invoked by another thread
  ##                             in the same process, false otherwise.

  ## <tt>rack.multiprocess</tt>:: true if an equivalent application object
  ##                              may be simultaneously invoked by another
  ##                              process, false otherwise.

  ## <tt>rack.run_once</tt>:: true if the server expects
  ##                          (but does not guarantee!) that the
  ##                          application will only be invoked this one
  ##                          time during the life of its containing
  ##                          process. Normally, this will only be true
  ##                          for a server based on CGI
  ##                          (or something similar).

  ## <tt>rack.hijack?</tt>:: present and true if the server supports
  ##                         connection hijacking. See below, hijacking.

  ## <tt>rack.hijack</tt>:: an object responding to #call that must be
  ##                        called at least once before using
  ##                        rack.hijack_io.
  ##                        It is recommended #call return rack.hijack_io
  ##                        as well as setting it in env if necessary.

  ## <tt>rack.hijack_io</tt>:: if rack.hijack? is true, and rack.hijack
  ##                           has received #call, this will contain
  ##                           an object resembling an IO. See hijacking.

  ## Additional environment specifications have approved to
  ## standardized middleware APIs.  None of these are required to
  ## be implemented by the server.

  ## <tt>rack.session</tt>:: A hash like interface for storing
  ##                         request session data.
  ##                         The store must implement:
  if session = env[RACK_SESSION]
    ##                         store(key, value)         (aliased as []=);
    unless session.respond_to?(:store) && session.respond_to?(:[]=)
      raise LintError, "session #{session.inspect} must respond to store and []="
    end

    ##                         fetch(key, default = nil) (aliased as []);
    unless session.respond_to?(:fetch) && session.respond_to?(:[])
      raise LintError, "session #{session.inspect} must respond to fetch and []"
    end

    ##                         delete(key);
    unless session.respond_to?(:delete)
      raise LintError, "session #{session.inspect} must respond to delete"
    end

    ##                         clear;
    unless session.respond_to?(:clear)
      raise LintError, "session #{session.inspect} must respond to clear"
    end

    ##                         to_hash (returning unfrozen Hash instance);
    unless session.respond_to?(:to_hash) && session.to_hash.kind_of?(Hash) && !session.to_hash.frozen?
      raise LintError, "session #{session.inspect} must respond to to_hash and return unfrozen Hash instance"
    end
  end

  ## <tt>rack.logger</tt>:: A common object interface for logging messages.
  ##                        The object must implement:
  if logger = env[RACK_LOGGER]
    ##                         info(message, &block)
    unless logger.respond_to?(:info)
      raise LintError, "logger #{logger.inspect} must respond to info"
    end

    ##                         debug(message, &block)
    unless logger.respond_to?(:debug)
      raise LintError, "logger #{logger.inspect} must respond to debug"
    end

    ##                         warn(message, &block)
    unless logger.respond_to?(:warn)
      raise LintError, "logger #{logger.inspect} must respond to warn"
    end

    ##                         error(message, &block)
    unless logger.respond_to?(:error)
      raise LintError, "logger #{logger.inspect} must respond to error"
    end

    ##                         fatal(message, &block)
    unless logger.respond_to?(:fatal)
      raise LintError, "logger #{logger.inspect} must respond to fatal"
    end
  end

  ## <tt>rack.multipart.buffer_size</tt>:: An Integer hint to the multipart parser as to what chunk size to use for reads and writes.
  if bufsize = env[RACK_MULTIPART_BUFFER_SIZE]
    unless bufsize.is_a?(Integer) && bufsize > 0
      raise LintError, "rack.multipart.buffer_size must be an Integer > 0 if specified"
    end
  end

  ## <tt>rack.multipart.tempfile_factory</tt>:: An object responding to #call with two arguments, the filename and content_type given for the multipart form field, and returning an IO-like object that responds to #<< and optionally #rewind. This factory will be used to instantiate the tempfile for each multipart form file upload field, rather than the default class of Tempfile.
  if tempfile_factory = env[RACK_MULTIPART_TEMPFILE_FACTORY]
    raise LintError, "rack.multipart.tempfile_factory must respond to #call" unless tempfile_factory.respond_to?(:call)
    env[RACK_MULTIPART_TEMPFILE_FACTORY] = lambda do |filename, content_type|
      io = tempfile_factory.call(filename, content_type)
      raise LintError, "rack.multipart.tempfile_factory return value must respond to #<<" unless io.respond_to?(:<<)
      io
    end
  end

  ## The server or the application can store their own data in the
  ## environment, too.  The keys must contain at least one dot,
  ## and should be prefixed uniquely.  The prefix <tt>rack.</tt>
  ## is reserved for use with the Rack core distribution and other
  ## accepted specifications and must not be used otherwise.
  ##

  %w[REQUEST_METHOD SERVER_NAME QUERY_STRING
     rack.version rack.input rack.errors
     rack.multithread rack.multiprocess rack.run_once].each { |header|
    raise LintError, "env missing required key #{header}" unless env.include? header
  }

  ## The <tt>SERVER_PORT</tt> must be an Integer if set.
  server_port = env["SERVER_PORT"]
  unless server_port.nil? || (Integer(server_port) rescue false)
    raise LintError, "env[SERVER_PORT] is not an Integer"
  end

  ## The <tt>SERVER_NAME</tt> must be a valid authority as defined by RFC7540.
  unless (URI.parse("http://#{env[SERVER_NAME]}/") rescue false)
    raise LintError, "#{env[SERVER_NAME]} must be a valid authority"
  end

  ## The <tt>HTTP_HOST</tt> must be a valid authority as defined by RFC7540.
  unless (URI.parse("http://#{env[HTTP_HOST]}/") rescue false)
    raise LintError, "#{env[HTTP_HOST]} must be a valid authority"
  end

  ## The environment must not contain the keys
  ## <tt>HTTP_CONTENT_TYPE</tt> or <tt>HTTP_CONTENT_LENGTH</tt>
  ## (use the versions without <tt>HTTP_</tt>).
  %w[HTTP_CONTENT_TYPE HTTP_CONTENT_LENGTH].each { |header|
    if env.include? header
      raise LintError, "env contains #{header}, must use #{header[5, -1]}"
    end
  }

  ## The CGI keys (named without a period) must have String values.
  ## If the string values for CGI keys contain non-ASCII characters,
  ## they should use ASCII-8BIT encoding.
  env.each { |key, value|
    next  if key.include? "."   # Skip extensions
    unless value.kind_of? String
      raise LintError, "env variable #{key} has non-string value #{value.inspect}"
    end
    next if value.encoding == Encoding::ASCII_8BIT
    unless value.b !~ /[\x80-\xff]/n
      raise LintError, "env variable #{key} has value containing non-ASCII characters and has non-ASCII-8BIT encoding #{value.inspect} encoding: #{value.encoding}"
    end
  }

  ## There are the following restrictions:

  ## * <tt>rack.version</tt> must be an array of Integers.
  unless env[RACK_VERSION].kind_of? Array
    raise LintError, "rack.version must be an Array, was #{env[RACK_VERSION].class}"
  end
  ## * <tt>rack.url_scheme</tt> must either be +http+ or +https+.
  unless %w[http https].include?(env[RACK_URL_SCHEME])
    raise LintError, "rack.url_scheme unknown: #{env[RACK_URL_SCHEME].inspect}"
  end

  ## * There must be a valid input stream in <tt>rack.input</tt>.
  check_input env[RACK_INPUT]
  ## * There must be a valid error stream in <tt>rack.errors</tt>.
  check_error env[RACK_ERRORS]
  ## * There may be a valid hijack stream in <tt>rack.hijack_io</tt>
  check_hijack env

  ## * The <tt>REQUEST_METHOD</tt> must be a valid token.
  unless env[REQUEST_METHOD] =~ /\A[0-9A-Za-z!\#$%&'*+.^_`|~-]+\z/
    raise LintError, "REQUEST_METHOD unknown: #{env[REQUEST_METHOD]}"
  end

  ## * The <tt>SCRIPT_NAME</tt>, if non-empty, must start with <tt>/</tt>
  if env.include?(SCRIPT_NAME) && env[SCRIPT_NAME] != "" && env[SCRIPT_NAME] !~ /\A\//
    raise LintError, "SCRIPT_NAME must start with /"
  end
  ## * The <tt>PATH_INFO</tt>, if non-empty, must start with <tt>/</tt>
  if env.include?(PATH_INFO) && env[PATH_INFO] != "" && env[PATH_INFO] !~ /\A\//
    raise LintError, "PATH_INFO must start with /"
  end
  ## * The <tt>CONTENT_LENGTH</tt>, if given, must consist of digits only.
  if env.include?("CONTENT_LENGTH") && env["CONTENT_LENGTH"] !~ /\A\d+\z/
    raise LintError, "Invalid CONTENT_LENGTH: #{env["CONTENT_LENGTH"]}"
  end

  ## * One of <tt>SCRIPT_NAME</tt> or <tt>PATH_INFO</tt> must be
  ##   set.  <tt>PATH_INFO</tt> should be <tt>/</tt> if
  ##   <tt>SCRIPT_NAME</tt> is empty.
  unless env[SCRIPT_NAME] || env[PATH_INFO]
    raise LintError, "One of SCRIPT_NAME or PATH_INFO must be set (make PATH_INFO '/' if SCRIPT_NAME is empty)"
  end
  ##   <tt>SCRIPT_NAME</tt> never should be <tt>/</tt>, but instead be empty.
  unless env[SCRIPT_NAME] != "/"
    raise LintError, "SCRIPT_NAME cannot be '/', make it '' and PATH_INFO '/'"
  end
end

#check_error(error) ⇒ Object

The Error Stream


490
491
492
493
494
495
496
497
# File 'lib/rack/lint.rb', line 490

def check_error(error)
  ## The error stream must respond to +puts+, +write+ and +flush+.
  [:puts, :write, :flush].each { |method|
    unless error.respond_to? method
      raise LintError, "rack.error #{error} does not respond to ##{method}"
    end
  }
end

#check_headers(header) ⇒ Object

The Headers


660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
# File 'lib/rack/lint.rb', line 660

def check_headers(header)
  ## The header must respond to +each+, and yield values of key and value.
  unless header.respond_to? :each
    raise LintError, "headers object should respond to #each, but doesn't (got #{header.class} as headers)"
  end

  header.each { |key, value|
    ## The header keys must be Strings.
    unless key.kind_of? String
      raise LintError, "header key must be a string, was #{key.class}"
    end

    ## Special headers starting "rack." are for communicating with the
    ## server, and must not be sent back to the client.
    next if key =~ /^rack\..+$/

    ## The header must not contain a +Status+ key.
    raise LintError, "header must not contain Status" if key.downcase == "status"
    ## The header must conform to RFC7230 token specification, i.e. cannot
    ## contain non-printable ASCII, DQUOTE or "(),/:;<=>[email protected][\]{}".
    raise LintError, "invalid header name: #{key}" if key =~ /[\(\),\/:;<=>\[email protected]\[\\\]{}[:cntrl:]]/

    ## The values of the header must be Strings,
    unless value.kind_of? String
      raise LintError, "a header value must be a String, but the value of '#{key}' is a #{value.class}"
    end
    ## consisting of lines (for multiple header values, e.g. multiple
    ## <tt>Set-Cookie</tt> values) separated by "\\n".
    value.split("\n").each { |item|
      ## The lines must not contain characters below 037.
      if item =~ /[\000-\037]/
        raise LintError, "invalid header value #{key}: #{item.inspect}"
      end
    }
  }
end

#check_hijack(env) ⇒ Object

Hijacking

AUTHORS: n.b. The trailing whitespace between paragraphs is important and should not be removed. The whitespace creates paragraphs in the RDoc output.

Request (before status)


552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
# File 'lib/rack/lint.rb', line 552

def check_hijack(env)
  if env[RACK_IS_HIJACK]
    ## If rack.hijack? is true then rack.hijack must respond to #call.
    original_hijack = env[RACK_HIJACK]
    raise LintError, "rack.hijack must respond to call" unless original_hijack.respond_to?(:call)
    env[RACK_HIJACK] = proc do
      ## rack.hijack must return the io that will also be assigned (or is
      ## already present, in rack.hijack_io.
      io = original_hijack.call
      HijackWrapper.new(io)
      ##
      ## rack.hijack_io must respond to:
      ## <tt>read, write, read_nonblock, write_nonblock, flush, close,
      ## close_read, close_write, closed?</tt>
      ##
      ## The semantics of these IO methods must be a best effort match to
      ## those of a normal ruby IO or Socket object, using standard
      ## arguments and raising standard exceptions. Servers are encouraged
      ## to simply pass on real IO objects, although it is recognized that
      ## this approach is not directly compatible with SPDY and HTTP 2.0.
      ##
      ## IO provided in rack.hijack_io should preference the
      ## IO::WaitReadable and IO::WaitWritable APIs wherever supported.
      ##
      ## There is a deliberate lack of full specification around
      ## rack.hijack_io, as semantics will change from server to server.
      ## Users are encouraged to utilize this API with a knowledge of their
      ## server choice, and servers may extend the functionality of
      ## hijack_io to provide additional features to users. The purpose of
      ## rack.hijack is for Rack to "get out of the way", as such, Rack only
      ## provides the minimum of specification and support.
      env[RACK_HIJACK_IO] = HijackWrapper.new(env[RACK_HIJACK_IO])
      io
    end
  else
    ##
    ## If rack.hijack? is false, then rack.hijack should not be set.
    raise LintError, "rack.hijack? is false, but rack.hijack is present" unless env[RACK_HIJACK].nil?
    ##
    ## If rack.hijack? is false, then rack.hijack_io should not be set.
    raise LintError, "rack.hijack? is false, but rack.hijack_io is present" unless env[RACK_HIJACK_IO].nil?
  end
end

#check_hijack_response(headers, env) ⇒ Object

Response (after headers)

It is also possible to hijack a response after the status and headers have been sent.


599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
# File 'lib/rack/lint.rb', line 599

def check_hijack_response(headers, env)

  # this check uses headers like a hash, but the spec only requires
  # headers respond to #each
  headers = Rack::Utils::HeaderHash[headers]

  ## In order to do this, an application may set the special header
  ## <tt>rack.hijack</tt> to an object that responds to <tt>call</tt>
  ## accepting an argument that conforms to the <tt>rack.hijack_io</tt>
  ## protocol.
  ##
  ## After the headers have been sent, and this hijack callback has been
  ## called, the application is now responsible for the remaining lifecycle
  ## of the IO. The application is also responsible for maintaining HTTP
  ## semantics. Of specific note, in almost all cases in the current SPEC,
  ## applications will have wanted to specify the header Connection:close in
  ## HTTP/1.1, and not Connection:keep-alive, as there is no protocol for
  ## returning hijacked sockets to the web server. For that purpose, use the
  ## body streaming API instead (progressively yielding strings via each).
  ##
  ## Servers must ignore the <tt>body</tt> part of the response tuple when
  ## the <tt>rack.hijack</tt> response API is in use.

  if env[RACK_IS_HIJACK] && headers[RACK_HIJACK]
    unless headers[RACK_HIJACK].respond_to? :call
      raise LintError, 'rack.hijack header must respond to #call'
    end
    original_hijack = headers[RACK_HIJACK]
    proc do |io|
      original_hijack.call HijackWrapper.new(io)
    end
  else
    ##
    ## The special response header <tt>rack.hijack</tt> must only be set
    ## if the request env has <tt>rack.hijack?</tt> <tt>true</tt>.
    unless headers[RACK_HIJACK].nil?
      raise LintError, 'rack.hijack header must not be present if server does not support hijacking'
    end

    nil
  end
end

#check_input(input) ⇒ Object

The Input Stream

The input stream is an IO-like object which contains the raw HTTP POST data.


374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
# File 'lib/rack/lint.rb', line 374

def check_input(input)
  ## When applicable, its external encoding must be "ASCII-8BIT" and it
  ## must be opened in binary mode, for Ruby 1.9 compatibility.
  if input.respond_to?(:external_encoding) && input.external_encoding != Encoding::ASCII_8BIT
    raise LintError, "rack.input #{input} does not have ASCII-8BIT as its external encoding"
  end
  if input.respond_to?(:binmode?) && !input.binmode?
    raise LintError, "rack.input #{input} is not opened in binary mode"
  end

  ## The input stream must respond to +gets+, +each+, +read+ and +rewind+.
  [:gets, :each, :read, :rewind].each { |method|
    unless input.respond_to? method
      raise LintError, "rack.input #{input} does not respond to ##{method}"
    end
  }
end

#check_status(status) ⇒ Object

The Status


651
652
653
654
655
656
657
# File 'lib/rack/lint.rb', line 651

def check_status(status)
  ## This is an HTTP status. It must be an Integer greater than or equal to
  ## 100.
  unless status.is_a?(Integer) && status >= 100
    raise LintError, "Status must be an Integer >=100"
  end
end

#closeObject

If the Body responds to close, it will be called after iteration. If the original Body is replaced by a new Body, the new Body must close the original Body after iteration, if it responds to close. If the Body responds to both to_ary and close, its implementation of to_ary must call close after iteration.


804
805
806
807
808
809
810
811
# File 'lib/rack/lint.rb', line 804

def close
  @closed = true
  @body.close  if @body.respond_to?(:close)
  index = @lint.index(self)
  unless @env['rack.lint'][0..index].all? {|lint| lint.instance_variable_get(:@closed)}
    raise LintError, "Body has not been closed"
  end
end

#eachObject

The Body


738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
# File 'lib/rack/lint.rb', line 738

def each
  @closed = false
  bytes = 0

  ## The Body must respond to +each+
  unless @body.respond_to?(:each)
    raise LintError, "Response body must respond to each"
  end

  @body.each { |part|
    ## and must only yield String values.
    unless part.kind_of? String
      raise LintError, "Body yielded non-string value #{part.inspect}"
    end
    ## 
    ## The Body itself should not be an instance of String, as this will
    ## break in Ruby 1.9.
    ## 
    ## Middleware must not call +each+ directly on the Body.
    ## Instead, middleware can return a new Body that calls +each+ on the
    ## original Body, yielding at least once per iteration.
    if @lint[0] == self
      @env['rack.lint.body_iteration'] += 1
    else
      if (@env['rack.lint.body_iteration'] -= 1) > 0
        raise LintError, "New body must yield at least once per iteration of old body"
      end
    end

    bytes += part.bytesize
    yield part
  }
  verify_content_length(bytes)

  verify_to_path
end

#respond_to?(sym) ⇒ Boolean

Returns:

  • (Boolean)

775
776
777
778
779
780
781
# File 'lib/rack/lint.rb', line 775

def respond_to?(sym, *)
  if sym.to_s == :to_ary
    @body.respond_to? sym
  else
    super
  end
end

#to_aryObject

If the Body responds to to_ary, it must return an Array whose contents are identical to that produced by calling each. Middleware may call to_ary directly on the Body and return a new Body in its place. In other words, middleware can only process the Body directly if it responds to to_ary.


788
789
790
791
792
793
794
795
796
# File 'lib/rack/lint.rb', line 788

def to_ary
  @body.to_ary.tap do |content|
    unless content == @body.enum_for.to_a
      raise LintError, "#to_ary not identical to contents produced by calling #each"
    end
  end
ensure
  close
end

#verify_content_length(bytes) ⇒ Object


725
726
727
728
729
730
731
732
733
734
735
# File 'lib/rack/lint.rb', line 725

def verify_content_length(bytes)
  if @head_request
    unless bytes == 0
      raise LintError, "Response body was given for HEAD request, but should be empty"
    end
  elsif @content_length
    unless @content_length == bytes.to_s
      raise LintError, "Content-Length header was #{@content_length}, but should be #{bytes}"
    end
  end
end

#verify_to_pathObject


813
814
815
816
817
818
819
820
821
822
823
824
825
# File 'lib/rack/lint.rb', line 813

def verify_to_path
  ##
  ## If the Body responds to +to_path+, it must return a String
  ## identifying the location of a file whose contents are identical
  ## to that produced by calling +each+; this may be used by the
  ## server as an alternative, possibly more efficient way to
  ## transport the response.
  if @body.respond_to?(:to_path)
    unless ::File.exist? @body.to_path
      raise LintError, "The file identified by body.to_path does not exist"
    end
  end
end