Plack::Request: die on superfluous arguments

I had some code that accidentally did
$plack_request->content_type($type) instead of
$plack_response->content_type($type), this just silently failed
instead of issuing a warning about the unknown argument.

I think Plack should die instead when you supply it with parameters
that it can't possibly do anything with. This is a partial hack to get
that going, this is just a proof of concept patch but a good start. In
order to fully execute on this we'd need to go through the whole plack
source and start dying on any unknown arguments.

This patch is best viewed with the --word-diff argument to git-show.

lib/Plack/Request.pm

@@ -23,29 +23,31 @@ sub new {
     bless { env => $env }, $class;
 }
 
-sub env { $_[0]->{env} }
-
-sub address     { $_[0]->env->{REMOTE_ADDR} }
-sub remote_host { $_[0]->env->{REMOTE_HOST} }
-sub protocol    { $_[0]->env->{SERVER_PROTOCOL} }
-sub method      { $_[0]->env->{REQUEST_METHOD} }
-sub port        { $_[0]->env->{SERVER_PORT} }
-sub user        { $_[0]->env->{REMOTE_USER} }
-sub request_uri { $_[0]->env->{REQUEST_URI} }
-sub path_info   { $_[0]->env->{PATH_INFO} }
-sub path        { $_[0]->env->{PATH_INFO} || '/' }
-sub script_name { $_[0]->env->{SCRIPT_NAME} }
-sub scheme      { $_[0]->env->{'psgi.url_scheme'} }
-sub secure      { $_[0]->scheme eq 'https' }
-sub body        { $_[0]->env->{'psgi.input'} }
-sub input       { $_[0]->env->{'psgi.input'} }
-
-sub content_length   { $_[0]->env->{CONTENT_LENGTH} }
-sub content_type     { $_[0]->env->{CONTENT_TYPE} }
-
-sub session         { $_[0]->env->{'psgix.session'} }
-sub session_options { $_[0]->env->{'psgix.session.options'} }
-sub logger          { $_[0]->env->{'psgix.logger'} }
+my $does_not_take_any_arguments_error = "This method doesn't take any arguments";
+
+sub env { my $self = shift; die $does_not_take_any_arguments_error if @_; $self->{env} }
+
+sub address     { my $self = shift; die $does_not_take_any_arguments_error if @_; $self->env->{REMOTE_ADDR} }
+sub remote_host { my $self = shift; die $does_not_take_any_arguments_error if @_; $self->env->{REMOTE_HOST} }
+sub protocol    { my $self = shift; die $does_not_take_any_arguments_error if @_; $self->env->{SERVER_PROTOCOL} }
+sub method      { my $self = shift; die $does_not_take_any_arguments_error if @_; $self->env->{REQUEST_METHOD} }
+sub port        { my $self = shift; die $does_not_take_any_arguments_error if @_; $self->env->{SERVER_PORT} }
+sub user        { my $self = shift; die $does_not_take_any_arguments_error if @_; $self->env->{REMOTE_USER} }
+sub request_uri { my $self = shift; die $does_not_take_any_arguments_error if @_; $self->env->{REQUEST_URI} }
+sub path_info   { my $self = shift; die $does_not_take_any_arguments_error if @_; $self->env->{PATH_INFO} }
+sub path        { my $self = shift; die $does_not_take_any_arguments_error if @_; $self->env->{PATH_INFO} || '/' }
+sub script_name { my $self = shift; die $does_not_take_any_arguments_error if @_; $self->env->{SCRIPT_NAME} }
+sub scheme      { my $self = shift; die $does_not_take_any_arguments_error if @_; $self->env->{'psgi.url_scheme'} }
+sub secure      { my $self = shift; die $does_not_take_any_arguments_error if @_; $self->scheme eq 'https' }
+sub body        { my $self = shift; die $does_not_take_any_arguments_error if @_; $self->env->{'psgi.input'} }
+sub input       { my $self = shift; die $does_not_take_any_arguments_error if @_; $self->env->{'psgi.input'} }
+
+sub content_length   { my $self = shift; die $does_not_take_any_arguments_error if @_; $self->env->{CONTENT_LENGTH} }
+sub content_type     { my $self = shift; die $does_not_take_any_arguments_error if @_; $self->env->{CONTENT_TYPE} }
+
+sub session         { my $self = shift; die $does_not_take_any_arguments_error if @_; $self->env->{'psgix.session'} }
+sub session_options { my $self = shift; die $does_not_take_any_arguments_error if @_; $self->env->{'psgix.session.options'} }
+sub logger          { my $self = shift; die $does_not_take_any_arguments_error if @_; $self->env->{'psgix.logger'} }
 
 sub cookies {
     my $self = shift;
@@ -98,7 +100,7 @@ sub content {
     return $content;
 }
 
-sub raw_body { $_[0]->content }
+sub raw_body { my $self = shift; die $does_not_take_any_arguments_error if @_; $self->content }
 
 # XXX you can mutate headers with ->headers but it's not written through to the env