from abjad import *


def test_spanner_extend_left_01( ):
   '''Extend spanner to the left.'''

   t = Voice(Container(construct.run(2)) * 3)
   pitchtools.diatonicize(t)
   p = Beam(t[1])

   r'''\new Voice {
      {
         c'8
         d'8
      }
      {
         e'8 [
         f'8 ]
      }
      {
         g'8
         a'8
      }
   }'''

   p.extend_left(t[0][:])

   r'''\new Voice {
      {
         c'8 [
         d'8
      }
      {
         e'8 
         f'8
      }
      {
         g'8
         a'8 ]
      }
   }'''

   assert check.wf(t)
   assert t.format == "\\new Voice {\n\t{\n\t\tc'8 [\n\t\td'8\n\t}\n\t{\n\t\te'8\n\t\tf'8 ]\n\t}\n\t{\n\t\tg'8\n\t\ta'8\n\t}\n}"


def test_spanner_extend_left_02( ):
   '''Extend spanner to the left.'''
   
   t = Voice(Container(construct.run(2)) * 3)
   pitchtools.diatonicize(t)
   p = Beam(t[1])

   r'''\new Voice {
      {
         c'8
         d'8
      }
      {
         e'8 [
         f'8 ]
      }
      {
         g'8
         a'8
      }
   }'''

   p.extend_left(t[0:1])

   r'''\new Voice {
      {
         c'8 [
         d'8
      }
      {
         e'8 
         f'8 ]
      }
      {
         g'8 
         a'8 
      }
   }'''

   assert t.format == "\\new Voice {\n\t{\n\t\tc'8 [\n\t\td'8\n\t}\n\t{\n\t\te'8\n\t\tf'8 ]\n\t}\n\t{\n\t\tg'8\n\t\ta'8\n\t}\n}"
