Allow setting g:powerline_pyeval to PowerlinePyeval for testing

powerline/vim.py

@@ -2,6 +2,7 @@
 from __future__ import (unicode_literals, division, absolute_import, print_function)
 
 import sys
+import json
 
 from itertools import count
 
@@ -11,9 +12,6 @@ from powerline.bindings.vim import vim_get_func, vim_getvar
 from powerline import Powerline, FailedUnicode
 from powerline.lib import mergedicts
 
-if not hasattr(vim, 'bindeval'):
-	import json
-
 
 def _override_from(config, override_varname):
 	try:
@@ -134,7 +132,7 @@ class VimPowerline(Powerline):
 		set_pycmd(pycmd)
 
 		# pyeval() and vim.bindeval were both introduced in one patch
-		if not hasattr(vim, 'bindeval') and can_replace_pyeval:
+		if (not hasattr(vim, 'bindeval') and can_replace_pyeval) or pyeval == 'PowerlinePyeval':
 			vim.command(('''
 				function! PowerlinePyeval(e)
 					{pycmd} powerline.do_pyeval()
@@ -245,14 +243,15 @@ class VimPowerline(Powerline):
 	def new_window(self):
 		return self.render(*self.win_idx(None))
 
-	if not hasattr(vim, 'bindeval'):
-		# Method for PowerlinePyeval function. Is here to reduce the number of 
-		# requirements to __main__ globals to just one powerline object 
-		# (previously it required as well vim and json)
-		@staticmethod
-		def do_pyeval():
-			import __main__
-			vim.command('return ' + json.dumps(eval(vim.eval('a:e'), __main__.__dict__)))
+	@staticmethod
+	def do_pyeval():
+		'''Evaluate python string passed to PowerlinePyeval
+
+		Is here to reduce the number of requirements to __main__ globals to just 
+		one powerline object (previously it required as well vim and json).
+		'''
+		import __main__
+		vim.command('return ' + json.dumps(eval(vim.eval('a:e'), __main__.__dict__)))
 
 	def setup_components(self, components):
 		if components is None: