--- a/src/testdir/test_ruby.vim
+++ b/src/testdir/test_ruby.vim
@@ -34,7 +34,7 @@ func Test_rubyfile()
   call delete(tempfile)
 endfunc
 
-func Test_set_cursor()
+func Test_ruby_set_cursor()
   " Check that setting the cursor position works.
   new
   call setline(1, ['first line', 'second line'])
@@ -54,7 +54,7 @@ func Test_set_cursor()
 endfunc
 
 " Test buffer.count and buffer.length (number of lines in buffer)
-func Test_buffer_count()
+func Test_ruby_buffer_count()
   new
   call setline(1, ['one', 'two', 'three'])
   call assert_equal(3, rubyeval('$curbuf.count'))
@@ -63,7 +63,7 @@ func Test_buffer_count()
 endfunc
 
 " Test buffer.name (buffer name)
-func Test_buffer_name()
+func Test_ruby_buffer_name()
   new Xfoo
   call assert_equal(expand('%:p'), rubyeval('$curbuf.name'))
   bwipe
@@ -71,7 +71,7 @@ func Test_buffer_name()
 endfunc
 
 " Test buffer.number (number of the buffer).
-func Test_buffer_number()
+func Test_ruby_buffer_number()
   new
   call assert_equal(bufnr('%'), rubyeval('$curbuf.number'))
   new
@@ -81,7 +81,7 @@ func Test_buffer_number()
 endfunc
 
 " Test buffer.delete({n}) (delete line {n})
-func Test_buffer_delete()
+func Test_ruby_buffer_delete()
   new
   call setline(1, ['one', 'two', 'three'])
   ruby $curbuf.delete(2)
@@ -94,7 +94,7 @@ func Test_buffer_delete()
 endfunc
 
 " Test buffer.append({str}, str) (append line {str} after line {n})
-func Test_buffer_append()
+func Test_ruby_buffer_append()
   new
   ruby $curbuf.append(0, 'one')
   ruby $curbuf.append(1, 'three')
@@ -112,7 +112,7 @@ func Test_buffer_append()
 endfunc
 
 " Test buffer.line (get or set the current line)
-func Test_buffer_line()
+func Test_ruby_buffer_line()
   new
   call setline(1, ['one', 'two', 'three'])
   2
@@ -125,7 +125,7 @@ func Test_buffer_line()
 endfunc
 
 " Test buffer.line_number (get current line number)
-func Test_buffer_line_number()
+func Test_ruby_buffer_line_number()
   new
   call setline(1, ['one', 'two', 'three'])
   2
@@ -134,7 +134,7 @@ func Test_buffer_line_number()
   bwipe!
 endfunc
 
-func Test_buffer_get()
+func Test_ruby_buffer_get()
   new
   call setline(1, ['one', 'two'])
   call assert_equal('one', rubyeval('$curbuf[1]'))
@@ -148,7 +148,7 @@ func Test_buffer_get()
   bwipe!
 endfunc
 
-func Test_buffer_set()
+func Test_ruby_buffer_set()
   new
   call setline(1, ['one', 'two'])
   ruby $curbuf[2] = 'TWO'
@@ -162,7 +162,7 @@ func Test_buffer_set()
 endfunc
 
 " Test window.width (get or set window height).
-func Test_window_height()
+func Test_ruby_window_height()
   new
 
   " Test setting window height
@@ -176,7 +176,7 @@ func Test_window_height()
 endfunc
 
 " Test window.width (get or set window width).
-func Test_window_width()
+func Test_ruby_window_width()
   vnew
 
   " Test setting window width
@@ -190,7 +190,7 @@ func Test_window_width()
 endfunc
 
 " Test window.buffer (get buffer object of a window object).
-func Test_window_buffer()
+func Test_ruby_window_buffer()
   new Xfoo1
   new Xfoo2
   ruby $b2 = $curwin.buffer
@@ -209,14 +209,14 @@ func Test_window_buffer()
 endfunc
 
 " Test Vim::Window.current (get current window object)
-func Test_Vim_window_current()
+func Test_ruby_Vim_window_current()
   let cw = rubyeval('$curwin')
   call assert_equal(cw, rubyeval('Vim::Window.current'))
   call assert_match('^#<Vim::Window:0x\x\+>$', cw)
 endfunc
 
 " Test Vim::Window.count (number of windows)
-func Test_Vim_window_count()
+func Test_ruby_Vim_window_count()
   new Xfoo1
   new Xfoo2
   split
@@ -226,7 +226,7 @@ func Test_Vim_window_count()
 endfunc
 
 " Test Vim::Window[n] (get window object of window n)
-func Test_Vim_window_get()
+func Test_ruby_Vim_window_get()
   new Xfoo1
   new Xfoo2
   call assert_match('Xfoo2$', rubyeval('Vim::Window[0].buffer.name'))
@@ -238,14 +238,14 @@ func Test_Vim_window_get()
 endfunc
 
 " Test Vim::Buffer.current (return the buffer object of current buffer)
-func Test_Vim_buffer_current()
+func Test_ruby_Vim_buffer_current()
   let cb = rubyeval('$curbuf')
   call assert_equal(cb, rubyeval('Vim::Buffer.current'))
   call assert_match('^#<Vim::Buffer:0x\x\+>$', cb)
 endfunc
 
 " Test Vim::Buffer:.count (return the number of buffers)
-func Test_Vim_buffer_count()
+func Test_ruby_Vim_buffer_count()
   new Xfoo1
   new Xfoo2
   call assert_equal(3, rubyeval('Vim::Buffer.count'))
@@ -254,7 +254,7 @@ func Test_Vim_buffer_count()
 endfunc
 
 " Test Vim::buffer[n] (return the buffer object of buffer number n)
-func Test_Vim_buffer_get()
+func Test_ruby_Vim_buffer_get()
   new Xfoo1
   new Xfoo2
 
@@ -269,7 +269,7 @@ endfunc
 
 " Test Vim::command({cmd}) (execute a Ex command))
 " Test Vim::command({cmd})
-func Test_Vim_command()
+func Test_ruby_Vim_command()
   new
   call setline(1, ['one', 'two', 'three', 'four'])
   ruby Vim::command('2,3d')
@@ -278,7 +278,7 @@ func Test_Vim_command()
 endfunc
 
 " Test Vim::set_option (set a vim option)
-func Test_Vim_set_option()
+func Test_ruby_Vim_set_option()
   call assert_equal(0, &number)
   ruby Vim::set_option('number')
   call assert_equal(1, &number)
@@ -286,14 +286,16 @@ func Test_Vim_set_option()
   call assert_equal(0, &number)
 endfunc
 
-func Test_Vim_evaluate()
+func Test_ruby_Vim_evaluate()
   call assert_equal(123,        rubyeval('Vim::evaluate("123")'))
   " Vim::evaluate("123").class gives Integer or Fixnum depending
   " on versions of Ruby.
   call assert_match('^Integer\|Fixnum$', rubyeval('Vim::evaluate("123").class'))
 
-  call assert_equal(1.23,       rubyeval('Vim::evaluate("1.23")'))
-  call assert_equal('Float',    rubyeval('Vim::evaluate("1.23").class'))
+  if has('float')
+    call assert_equal(1.23,       rubyeval('Vim::evaluate("1.23")'))
+    call assert_equal('Float',    rubyeval('Vim::evaluate("1.23").class'))
+  endif
 
   call assert_equal('foo',      rubyeval('Vim::evaluate("\"foo\"")'))
   call assert_equal('String',   rubyeval('Vim::evaluate("\"foo\"").class'))
@@ -319,14 +321,14 @@ func Test_Vim_evaluate()
   call assert_equal('FalseClass',rubyeval('Vim::evaluate("v:false").class'))
 endfunc
 
-func Test_Vim_blob()
+func Test_ruby_Vim_blob()
   call assert_equal('0z',         rubyeval('Vim::blob("")'))
   call assert_equal('0z31326162', rubyeval('Vim::blob("12ab")'))
   call assert_equal('0z00010203', rubyeval('Vim::blob("\x00\x01\x02\x03")'))
   call assert_equal('0z8081FEFF', rubyeval('Vim::blob("\x80\x81\xfe\xff")'))
 endfunc
 
-func Test_Vim_evaluate_list()
+func Test_ruby_Vim_evaluate_list()
   call setline(line('$'), ['2 line 2'])
   ruby Vim.command("normal /^2\n")
   let l = ["abc", "def"]
@@ -340,7 +342,7 @@ EOF
   call assert_equal('abc/def', getline('$'))
 endfunc
 
-func Test_Vim_evaluate_dict()
+func Test_ruby_Vim_evaluate_dict()
   let d = {'a': 'foo', 'b': 123}
   redir => l:out
   ruby d = Vim.evaluate("d"); print d
@@ -349,13 +351,13 @@ func Test_Vim_evaluate_dict()
 endfunc
 
 " Test Vim::message({msg}) (display message {msg})
-func Test_Vim_message()
+func Test_ruby_Vim_message()
   ruby Vim::message('A message')
   let messages = split(execute('message'), "\n")
   call assert_equal('A message', messages[-1])
 endfunc
 
-func Test_print()
+func Test_ruby_print()
   func RubyPrint(expr)
     return trim(execute('ruby print ' . a:expr))
   endfunc
@@ -374,7 +376,7 @@ func Test_print()
   delfunc RubyPrint
 endfunc
 
-func Test_p()
+func Test_ruby_p()
   ruby p 'Just a test'
   let messages = split(execute('message'), "\n")
   call assert_equal('"Just a test"', messages[-1])