Test completion.

IPython/frontend/linefrontendbase.py

@@ -204,6 +204,12 b' class LineFrontEndBase(FrontEndBase):'
             print >>sys.__stdout__, completions 
 
 
+    def get_line_width(self):
+        """ Return the width of the line in characters.
+        """
+        return 80
+
+
     def write_completion(self, possibilities):
         """ Write the list of possible completions.
         """
@@ -212,8 +218,8 b' class LineFrontEndBase(FrontEndBase):'
         self.write('\n')
         max_len = len(max(possibilities, key=len)) + 1
         
-        #now we check how much symbol we can put on a line...
-        chars_per_line =self.get_line_width()
+        # Now we check how much symbol we can put on a line...
+        chars_per_line = self.get_line_width()
         symbols_per_line = max(1, chars_per_line/max_len)
 
         pos = 1
@@ -231,7 +237,6 b' class LineFrontEndBase(FrontEndBase):'
         self.input_buffer = current_buffer
 
 
-
     def new_prompt(self, prompt):
         """ Prints a prompt and starts a new editing buffer. 
 

IPython/frontend/tests/test_prefilterfrontend.py

@@ -115,6 +115,9 b' def test_completion():'
     f.input_buffer = 'zzzb = 2'
     f._on_enter()
     f.input_buffer = 'zz'
+    f.complete_current_input()
+    assert f.out.getvalue() == '\nzzza zzzb '
+    assert f.input_buffer == 'zzz'
 
 
 if __name__ == '__main__':
@@ -123,3 +126,4 b" if __name__ == '__main__':"
     test_execution()
     test_multiline()
     test_capture()
+    test_completion()