Rely on input #size instead of #length in MockRequest.env_for

StringIO is the only IO object that responds to #length, the Ruby IO
interface actually uses #size. Furthermore #size is actually implemented
on IO-like inputs on web servers like Unicorn and Passenger (TeeInput).

This change allows using (Temp)file objects as the Rack input.

3 files changed, 10 insertions, 4 deletions

diff --git a/lib/rack/mock.rb b/lib/rack/mock.rb
index f3321772..d2ef2659 100644
--- a/lib/rack/mock.rb
+++ b/lib/rack/mock.rb
@@ -139,7 +139,7 @@ module Rack
       rack_input.set_encoding(Encoding::BINARY)
       env[RACK_INPUT] = rack_input
 
-      env["CONTENT_LENGTH"] ||= env[RACK_INPUT].length.to_s
+      env["CONTENT_LENGTH"] ||= env[RACK_INPUT].size.to_s
 
       opts.each { |field, value|
         env[field] = value  if String === field
diff --git a/test/spec_mock.rb b/test/spec_mock.rb
index a4d4e5a5..6e5555d1 100644
--- a/test/spec_mock.rb
+++ b/test/spec_mock.rb
@@ -84,6 +84,12 @@ describe Rack::MockRequest do
   it "set content length" do
     env = Rack::MockRequest.env_for("/", :input => "foo")
     env["CONTENT_LENGTH"].must_equal "3"
+
+    env = Rack::MockRequest.env_for("/", :input => StringIO.new("foo"))
+    env["CONTENT_LENGTH"].must_equal "3"
+
+    env = Rack::MockRequest.env_for("/", :input => Tempfile.new("name").tap { |t| t << "foo" })
+    env["CONTENT_LENGTH"].must_equal "3"
   end
 
   it "allow posting" do
diff --git a/test/spec_multipart.rb b/test/spec_multipart.rb
index 2f957d92..6f1f0d9a 100644
--- a/test/spec_multipart.rb
+++ b/test/spec_multipart.rb
@@ -107,8 +107,8 @@ describe Rack::Multipart do
     def rd.rewind; end
     wr.sync = true
 
-    # mock out length to make this pipe look like a Tempfile
-    def rd.length
+    # mock out size to make this pipe look like a Tempfile
+    def rd.size
       1024 * 1024 * 8
     end
 
@@ -136,7 +136,7 @@ describe Rack::Multipart do
 
     fixture = {
       "CONTENT_TYPE" => "multipart/form-data; boundary=AaB03x",
-      "CONTENT_LENGTH" => rd.length.to_s,
+      "CONTENT_LENGTH" => rd.size.to_s,
       :input => rd,
     }