File.open fails given nonexistent path or path to a dir. Closes #82.

* Removed unnecessary paths from existing tests (they don't
  need to exercise paths).
* Added tests for nonexistent, existing and trying to open
  a directory.

lib/fakefs/file.rb

@@ -398,8 +398,22 @@ module FakeFS
       (@mode & mask) != 0 if @mode.is_a?(Integer)
     end
 
+    # Create a missing file if the path's valid.
+    #
     def create_missing_file
-      if !File.exists?(@path)
+      raise Errno::EISDIR, "Is a directory - #{path}" if File.directory?(@path)
+
+      if !File.exists?(@path)   # Unnecessary check, probably.
+        dirname = RealFile.dirname @path
+
+        unless dirname == "."
+          dir = FileSystem.find dirname
+
+          unless dir.kind_of? FakeDir
+            raise Errno::ENOENT, "No such file or directory - #{path}"
+          end
+        end
+
         @file = FileSystem.add(path, FakeFile.new)
       end
     end

test/fakefs_test.rb

@@ -175,8 +175,8 @@ class FakeFSTest < Test::Unit::TestCase
     assert File.symlink?(link)
   end
 
-  def test_can_create_files
+  def test_can_create_files_in_current_dir
-    path = '/path/to/file.txt'
+    path = 'file.txt'
     File.open(path, 'w') do |f|
       f.write "Yatta!"
     end
@@ -186,7 +186,44 @@ class FakeFSTest < Test::Unit::TestCase
     assert File.writable?(path)
   end
 
+  def test_can_create_files_in_existing_dir
+    FileUtils.mkdir_p "/path/to"
+    path = "/path/to/file.txt"
+
+    File.open(path, 'w') do |f|
+      f.write "Yatta!"
+    end
+
+    assert File.exists?(path)
+    assert File.readable?(path)
+    assert File.writable?(path)
+  end
+
+  def test_raises_ENOENT_trying_to_create_files_in_nonexistent_dir
+    path = "/path/to/file.txt"
+
+    assert_raises(Errno::ENOENT) {
+      File.open(path, 'w') do |f|
+        f.write "Yatta!"
+      end
+    }
+  end
+
+  def test_raises_EISDIR_if_trying_to_open_existing_directory_name
+    path = "/path/to"
+
+    FileUtils.mkdir_p path
+
+    assert_raises(Errno::EISDIR) {
+      File.open(path, 'w') do |f|
+        f.write "Yatta!"
+      end
+    }
+  end
+
   def test_can_create_files_with_bitmasks
+    FileUtils.mkdir_p("/path/to")
+
     path = '/path/to/file.txt'
     File.open(path, File::RDWR | File::CREAT) do |f|
       f.write "Yatta!"
@@ -305,7 +342,7 @@ class FakeFSTest < Test::Unit::TestCase
   end
 
   def test_can_read_files_once_written
-    path = '/path/to/file.txt'
+    path = 'file.txt'
     File.open(path, 'w') do |f|
       f.write "Yatta!"
     end
@@ -314,7 +351,7 @@ class FakeFSTest < Test::Unit::TestCase
   end
 
   def test_can_write_to_files
-    path = '/path/to/file.txt'
+    path = 'file.txt'
     File.open(path, 'w') do |f|
       f << 'Yada Yada'
     end
@@ -328,11 +365,12 @@ class FakeFSTest < Test::Unit::TestCase
   end
 
   def test_can_open_file_in_binary_mode
-    File.open("/foo", "wb") { |x| x << "a" }
+    File.open("foo", "wb") { |x| x << "a" }
-    assert_equal "a", File.read("/foo")
+    assert_equal "a", File.read("foo")
   end
 
   def test_can_chunk_io_when_reading
+    FileUtils.mkdir_p "/path/to"
     path = '/path/to/file.txt'
     File.open(path, 'w') do |f|
       f << 'Yada Yada'
@@ -346,7 +384,7 @@ class FakeFSTest < Test::Unit::TestCase
   end
 
   def test_can_get_size_of_files
-    path = '/path/to/file.txt'
+    path = 'file.txt'
     File.open(path, 'w') do |f|
       f << 'Yada Yada'
     end
@@ -354,20 +392,20 @@ class FakeFSTest < Test::Unit::TestCase
   end
 
   def test_can_check_if_file_has_size?
-    path = '/path/to/file.txt'
+    path = 'file.txt'
     File.open(path, 'w') do |f|
       f << 'Yada Yada'
     end
     assert File.size?(path)
-    assert_nil File.size?("/path/to/other.txt")
+    assert_nil File.size?("other.txt")
   end
 
   def test_can_check_size_of_empty_file
-    path = '/path/to/file.txt'
+    path = 'file.txt'
     File.open(path, 'w') do |f|
       f << ''
     end
-    assert_nil File.size?("/path/to/file.txt")
+    assert_nil File.size?("file.txt")
   end
 
   def test_raises_error_on_mtime_if_file_does_not_exist
@@ -377,16 +415,16 @@ class FakeFSTest < Test::Unit::TestCase
   end
 
   def test_can_return_mtime_on_existing_file
-    path = '/path/to/file.txt'
+    path = 'file.txt'
     File.open(path, 'w') do |f|
       f << ''
     end
-    assert File.mtime('/path/to/file.txt').is_a?(Time)
+    assert File.mtime('file.txt').is_a?(Time)
   end
 
   def test_raises_error_on_ctime_if_file_does_not_exist
     assert_raise Errno::ENOENT do
-      File.ctime('/path/to/file.txt')
+      File.ctime('file.txt')
     end
   end
 
@@ -446,16 +484,16 @@ class FakeFSTest < Test::Unit::TestCase
 
   def test_can_call_utime_on_an_existing_file
     time = Time.now - 300 # Not now
-    path = '/path/to/file.txt'
+    path = 'file.txt'
     File.open(path, 'w') do |f|
       f << ''
     end
     File.utime(time, time, path)
-    assert_equal time, File.mtime('/path/to/file.txt')
+    assert_equal time, File.mtime('file.txt')
   end
 
   def test_utime_returns_number_of_paths
-    path1, path2 = '/path/to/file.txt', '/path/to/another_file.txt'
+    path1, path2 = 'file.txt', 'another_file.txt'
     [path1, path2].each do |path|
       File.open(path, 'w') do |f|
         f << ''
@@ -465,7 +503,7 @@ class FakeFSTest < Test::Unit::TestCase
   end
 
   def test_can_read_with_File_readlines
-    path = '/path/to/file.txt'
+    path = 'file.txt'
     File.open(path, 'w') do |f|
       f.puts "Yatta!", "Gatta!"
       f.puts ["woot","toot"]
@@ -475,7 +513,7 @@ class FakeFSTest < Test::Unit::TestCase
   end
 
   def test_File_close_disallows_further_access
-    path = '/path/to/file.txt'
+    path = 'file.txt'
     file = File.open(path, 'w')
     file.write 'Yada'
     file.close
@@ -485,7 +523,7 @@ class FakeFSTest < Test::Unit::TestCase
   end
 
   def test_File_close_disallows_further_writes
-    path = '/path/to/file.txt'
+    path = 'file.txt'
     file = File.open(path, 'w')
     file.write 'Yada'
     file.close
@@ -495,7 +533,7 @@ class FakeFSTest < Test::Unit::TestCase
   end
 
   def test_can_read_from_file_objects
-    path = '/path/to/file.txt'
+    path = 'file.txt'
     File.open(path, 'w') do |f|
       f.write "Yatta!"
     end
@@ -510,7 +548,7 @@ class FakeFSTest < Test::Unit::TestCase
   end
 
   def test_knows_files_are_files
-    path = '/path/to/file.txt'
+    path = 'file.txt'
     File.open(path, 'w') do |f|
       f.write "Yatta!"
     end
@@ -519,17 +557,17 @@ class FakeFSTest < Test::Unit::TestCase
   end
 
   def test_File_io_returns_self
-    f = File.open("/foo", "w")
+    f = File.open("foo", "w")
     assert_equal f, f.to_io
   end
 
   def test_File_to_i_is_alias_for_filno
-    f = File.open("/foo", "w")
+    f = File.open("foo", "w")
     assert_equal f.method(:to_i), f.method(:fileno)
   end
 
   def test_knows_symlink_files_are_files
-    path = '/path/to/file.txt'
+    path = 'file.txt'
     File.open(path, 'w') do |f|
       f.write "Yatta!"
     end
@@ -615,6 +653,7 @@ class FakeFSTest < Test::Unit::TestCase
   end
 
   def test_dir_glob_handles_recursive_globs
+    FileUtils.mkdir_p "/one/two/three"
     File.open('/one/two/three/four.rb', 'w')
     File.open('/one/five.rb', 'w')
     assert_equal ['/one/five.rb', '/one/two/three/four.rb'], Dir['/one/**/*.rb']
@@ -623,6 +662,7 @@ class FakeFSTest < Test::Unit::TestCase
   end
 
   def test_dir_recursive_glob_ending_in_wildcards_returns_both_files_and_dirs
+    FileUtils.mkdir_p "/one/two/three"
     File.open('/one/two/three/four.rb', 'w')
     File.open('/one/five.rb', 'w')
     assert_equal ['/one/five.rb', '/one/two', '/one/two/three', '/one/two/three/four.rb'], Dir['/one/**/*']
@@ -640,7 +680,7 @@ class FakeFSTest < Test::Unit::TestCase
   end
 
   def test_should_report_pos_as_0_when_opening
-    File.open("/foo", "w") do |f|
+    File.open("foo", "w") do |f|
       f << "foobar"
       f.rewind
 
@@ -649,7 +689,7 @@ class FakeFSTest < Test::Unit::TestCase
   end
 
   def test_should_report_pos_as_1_when_seeking_one_char
-    File.open("/foo", "w") do |f|
+    File.open("foo", "w") do |f|
       f << "foobar"
 
       f.rewind
@@ -660,22 +700,22 @@ class FakeFSTest < Test::Unit::TestCase
   end
 
   def test_should_set_pos
-    File.open("/foo", "w") do |f|
+    File.open("foo", "w") do |f|
       f << "foo"
     end
 
-    fp = File.open("/foo", "r")
+    fp = File.open("foo", "r")
     fp.pos = 1
 
     assert_equal 1, fp.pos
   end
 
   def test_should_set_pos_with_tell_method
-    File.open("/foo", "w") do |f|
+    File.open("foo", "w") do |f|
       f << "foo"
     end
 
-    fp = File.open("/foo", "r")
+    fp = File.open("foo", "r")
     fp.tell = 1
 
     assert_equal 1, fp.pos

test/safe_test.rb

@@ -10,7 +10,7 @@ class FakeFSSafeTest < Test::Unit::TestCase
   end
 
   def test_FakeFS_method_does_not_intrude_on_global_namespace
-    path = '/path/to/file.txt'
+    path = 'file.txt'
 
     FakeFS do
       File.open(path, 'w') { |f| f.write "Yatta!" }