tests: refactor DummySource to read directly from files

This patch changes DummySource to follow a similar pattern to the
Maildir source, which works by opening the files directly for parsing.
Previously DummySource was parsing strings fed through StringIO,
which was introducing extra (or at least, different) complications with
encoding. See for example the comments in issue #205.

test/dummy_source.rb

@@ -25,32 +25,38 @@ def end_offset
     return @messages ? @messages.length - 1 : 0
   end
 
-  def load_header offset
-    Source.parse_raw_email_header StringIO.new(raw_header(offset))
+  def with_file_for id
+    fn = @messages[id]
+    File.open(fn, 'rb') { |f| yield f }
   end
 
-  def load_message offset
-    RMail::Parser.read raw_message(offset)
+  def load_header id
+    with_file_for(id) { |f| parse_raw_email_header f }
   end
 
-  def raw_header offset
+  def load_message id
+    with_file_for(id) { |f| RMail::Parser.read f }
+  end
+
+  def raw_header id
     ret = ""
-    f = StringIO.new(@messages[offset])
-    until f.eof? || (l = f.gets) =~ /^$/
-      ret += l
+    with_file_for(id) do |f|
+      until f.eof? || (l = f.gets) =~ /^$/
+        ret += l
+      end
     end
     ret
   end
 
-  def raw_message offset
-    @messages[offset]
+  def raw_message id
+    with_file_for(id) { |f| f.read }
   end
 
-  def each_raw_message_line offset
-    ret = ""
-    f = StringIO.new(@messages[offset])
-    until f.eof?
-      yield f.gets
+  def each_raw_message_line id
+    with_file_for(id) do |f|
+      until f.eof?
+        yield f.gets
+      end
     end
   end
 end

test/test_helper.rb

@@ -2,9 +2,12 @@
 require 'minitest/autorun'
 require "rr"
 
-def fixture(filename)
+def fixture_path(filename)
+  File.expand_path("../fixtures/#{filename}", __FILE__)
+end
+
+def fixture_contents(filename)
   file = ''
-  path = File.expand_path("../fixtures/#{filename}", __FILE__)
-  File.open(path) { |io| file = io.read }
+  File.open(fixture_path(filename)) { |io| file = io.read }
   file
-end
+end

test/test_message.rb

@@ -21,10 +21,8 @@ def teardown
   end
 
   def test_simple_message
-    message = fixture('simple-message.eml')
-
     source = DummySource.new("sup-test://test_simple_message")
-    source.messages = [ message ]
+    source.messages = [ fixture_path('simple-message.eml') ]
     source_info = 0
 
     sup_message = Message.build_from_source(source, source_info)
@@ -99,10 +97,8 @@ def test_simple_message
   end
 
   def test_multipart_message
-    message = fixture('multi-part.eml')
-
     source = DummySource.new("sup-test://test_multipart_message")
-    source.messages = [ message ]
+    source.messages = [ fixture_path('multi-part.eml') ]
     source_info = 0
 
     sup_message = Message.build_from_source(source, source_info)
@@ -126,10 +122,8 @@ def test_multipart_message
   end
 
   def test_broken_message_1
-    message = fixture('missing-from-to.eml')
-
     source = DummySource.new("sup-test://test_broken_message_1")
-    source.messages = [ message ]
+    source.messages = [ fixture_path('missing-from-to.eml') ]
     source_info = 0
 
     sup_message = Message.build_from_source(source, source_info)
@@ -150,10 +144,8 @@ def test_broken_message_1
   end
 
   def test_broken_message_2
-    message = fixture('no-body.eml')
-
     source = DummySource.new("sup-test://test_broken_message_1")
-    source.messages = [ message ]
+    source.messages = [ fixture_path('no-body.eml') ]
     source_info = 0
 
     sup_message = Message.build_from_source(source, source_info)
@@ -167,10 +159,8 @@ def test_broken_message_2
   end
 
   def test_multipart_message_2
-    message = fixture('multi-part-2.eml')
-
     source = DummySource.new("sup-test://test_multipart_message_2")
-    source.messages = [ message ]
+    source.messages = [ fixture_path('multi-part-2.eml') ]
     source_info = 0
 
     sup_message = Message.build_from_source(source, source_info)
@@ -182,10 +172,8 @@ def test_multipart_message_2
   end
 
   def test_text_attachment_decoding
-    message = fixture('text-attachments-with-charset.eml')
-
     source = DummySource.new("sup-test://test_text_attachment_decoding")
-    source.messages = [ message ]
+    source.messages = [ fixture_path('text-attachments-with-charset.eml') ]
     source_info = 0
 
     sup_message = Message.build_from_source(source, source_info)
@@ -210,10 +198,8 @@ def test_text_attachment_decoding
   end
 
   def test_mailing_list_header
-    message = fixture('mailing-list-header.eml')
-
     source = DummySource.new("sup-test://test_mailing_list_header")
-    source.messages = [ message ]
+    source.messages = [ fixture_path('mailing-list-header.eml') ]
     source_info = 0
 
     sup_message = Message.build_from_source(source, source_info)
@@ -227,10 +213,8 @@ def test_mailing_list_header
   end
 
   def test_blank_header_lines
-    message = fixture('blank-header-fields.eml')
-
     source = DummySource.new("sup-test://test_blank_header_lines")
-    source.messages = [ message ]
+    source.messages = [ fixture_path('blank-header-fields.eml') ]
     source_info = 0
 
     sup_message = Message.build_from_source(source, source_info)
@@ -249,10 +233,8 @@ def test_blank_header_lines
   end
 
   def test_malicious_attachment_names
-    message = fixture('malicious-attachment-names.eml')
-
     source = DummySource.new("sup-test://test_blank_header_lines")
-    source.messages = [ message ]
+    source.messages = [ fixture_path('malicious-attachment-names.eml') ]
     source_info = 0
 
     sup_message = Message.build_from_source(source, source_info)
@@ -276,10 +258,8 @@ def test_zimbra_quote_with_bottom_post
     # tries to do the right thing and reply after the quote.
     # In this case we want to just look at the > markers when determining where
     # the quoted chunk ends.
-    message = fixture('zimbra-quote-with-bottom-post.eml')
-
     source = DummySource.new("sup-test://test_zimbra_quote_with_bottom_post")
-    source.messages = [ message ]
+    source.messages = [ fixture_path('zimbra-quote-with-bottom-post.eml') ]
     source_info = 0
 
     sup_message = Message.build_from_source(source, source_info)

test/test_messages_dir.rb

@@ -21,11 +21,8 @@ def teardown
   end
 
   def test_binary_content_transfer_encoding
-    message = ''
-    File.open('test/fixtures/binary-content-transfer-encoding-2.eml') { |f| message = f.read }
-
     source = DummySource.new("sup-test://test_messages")
-    source.messages = [ message ]
+    source.messages = [ fixture_path('binary-content-transfer-encoding-2.eml') ]
     source_info = 0
 
     sup_message = Message.build_from_source(source, source_info)
@@ -53,11 +50,8 @@ def test_binary_content_transfer_encoding
   end
 
   def test_bad_content_transfer_encoding
-    message = ''
-    File.open('test/fixtures/bad-content-transfer-encoding-1.eml') { |f| message = f.read }
-
     source = DummySource.new("sup-test://test_messages")
-    source.messages = [ message ]
+    source.messages = [ fixture_path('bad-content-transfer-encoding-1.eml') ]
     source_info = 0
 
     sup_message = Message.build_from_source(source, source_info)
@@ -85,11 +79,8 @@ def test_bad_content_transfer_encoding
   end
 
   def test_missing_line
-    message = ''
-    File.open('test/fixtures/missing-line.eml') { |f| message = f.read }
-
     source = DummySource.new("sup-test://test_messages")
-    source.messages = [ message ]
+    source.messages = [ fixture_path('missing-line.eml') ]
     source_info = 0
 
     sup_message = Message.build_from_source(source, source_info)