Add tests for null cleanup test.

IPython/core/tests/test_inputtransformer2.py

@@ -1,217 +1,227 b''
 """Tests for the token-based transformers in IPython.core.inputtransformer2
 
 Line-based transformers are the simpler ones; token-based transformers are
 more complex. See test_inputtransformer2_line for tests for line-based
 transformations.
 """
 import nose.tools as nt
 import string
 
 from IPython.core import inputtransformer2 as ipt2
 from IPython.core.inputtransformer2 import make_tokens_by_line
 
 MULTILINE_MAGIC = ("""\
 a = f()
 %foo \\
 bar
 g()
 """.splitlines(keepends=True), (2, 0), """\
 a = f()
 get_ipython().run_line_magic('foo', ' bar')
 g()
 """.splitlines(keepends=True))
 
 INDENTED_MAGIC = ("""\
 for a in range(5):
     %ls
 """.splitlines(keepends=True), (2, 4), """\
 for a in range(5):
     get_ipython().run_line_magic('ls', '')
 """.splitlines(keepends=True))
 
 MULTILINE_MAGIC_ASSIGN = ("""\
 a = f()
 b = %foo \\
   bar
 g()
 """.splitlines(keepends=True), (2, 4), """\
 a = f()
 b = get_ipython().run_line_magic('foo', '   bar')
 g()
 """.splitlines(keepends=True))
 
 MULTILINE_SYSTEM_ASSIGN = ("""\
 a = f()
 b = !foo \\
   bar
 g()
 """.splitlines(keepends=True), (2, 4), """\
 a = f()
 b = get_ipython().getoutput('foo    bar')
 g()
 """.splitlines(keepends=True))
 
 AUTOCALL_QUOTE = (
     [",f 1 2 3\n"], (1, 0),
     ['f("1", "2", "3")\n']
 )
 
 AUTOCALL_QUOTE2 = (
     [";f 1 2 3\n"], (1, 0),
     ['f("1 2 3")\n']
 )
 
 AUTOCALL_PAREN = (
     ["/f 1 2 3\n"], (1, 0),
     ['f(1, 2, 3)\n']
 )
 
 SIMPLE_HELP = (
     ["foo?\n"], (1, 0),
     ["get_ipython().run_line_magic('pinfo', 'foo')\n"]
 )
 
 DETAILED_HELP = (
     ["foo??\n"], (1, 0),
     ["get_ipython().run_line_magic('pinfo2', 'foo')\n"]
 )
 
 MAGIC_HELP = (
     ["%foo?\n"], (1, 0),
     ["get_ipython().run_line_magic('pinfo', '%foo')\n"]
 )
 
 HELP_IN_EXPR = (
     ["a = b + c?\n"], (1, 0),
     ["get_ipython().set_next_input('a = b + c');"
      "get_ipython().run_line_magic('pinfo', 'c')\n"]
 )
 
 HELP_CONTINUED_LINE = ("""\
 a = \\
 zip?
 """.splitlines(keepends=True), (1, 0),
 [r"get_ipython().set_next_input('a = \\\nzip');get_ipython().run_line_magic('pinfo', 'zip')" + "\n"]
 )
 
 HELP_MULTILINE = ("""\
 (a,
 b) = zip?
 """.splitlines(keepends=True), (1, 0),
 [r"get_ipython().set_next_input('(a,\nb) = zip');get_ipython().run_line_magic('pinfo', 'zip')" + "\n"]
 )
 
+def null_cleanup_transformer(lines):
+    """
+    A cleanup transform that returns an empty list.
+    """
+    return []
+
 def check_make_token_by_line_never_ends_empty():
     """
     Check that not sequence of single or double characters ends up leading to en empty list of tokens
     """
     from string import printable
     for c in printable:
         nt.assert_not_equal(make_tokens_by_line(c)[-1], [])
         for k in printable:
             nt.assert_not_equal(make_tokens_by_line(c+k)[-1], [])
 
 def check_find(transformer, case, match=True):
     sample, expected_start, _  = case
     tbl = make_tokens_by_line(sample)
     res = transformer.find(tbl)
     if match:
         # start_line is stored 0-indexed, expected values are 1-indexed
         nt.assert_equal((res.start_line+1, res.start_col), expected_start)
         return res
     else:
         nt.assert_is(res, None)
 
 def check_transform(transformer_cls, case):
     lines, start, expected = case
     transformer = transformer_cls(start)
     nt.assert_equal(transformer.transform(lines), expected)
 
 def test_continued_line():
     lines = MULTILINE_MAGIC_ASSIGN[0]
     nt.assert_equal(ipt2.find_end_of_continued_line(lines, 1), 2)
 
     nt.assert_equal(ipt2.assemble_continued_line(lines, (1, 5), 2), "foo    bar")
 
 def test_find_assign_magic():
     check_find(ipt2.MagicAssign, MULTILINE_MAGIC_ASSIGN)
     check_find(ipt2.MagicAssign, MULTILINE_SYSTEM_ASSIGN, match=False)
 
 def test_transform_assign_magic():
     check_transform(ipt2.MagicAssign, MULTILINE_MAGIC_ASSIGN)
 
 def test_find_assign_system():
     check_find(ipt2.SystemAssign, MULTILINE_SYSTEM_ASSIGN)
     check_find(ipt2.SystemAssign, (["a =  !ls\n"], (1, 5), None))
     check_find(ipt2.SystemAssign, (["a=!ls\n"], (1, 2), None))
     check_find(ipt2.SystemAssign, MULTILINE_MAGIC_ASSIGN, match=False)
 
 def test_transform_assign_system():
     check_transform(ipt2.SystemAssign, MULTILINE_SYSTEM_ASSIGN)
 
 def test_find_magic_escape():
     check_find(ipt2.EscapedCommand, MULTILINE_MAGIC)
     check_find(ipt2.EscapedCommand, INDENTED_MAGIC)
     check_find(ipt2.EscapedCommand, MULTILINE_MAGIC_ASSIGN, match=False)
 
 def test_transform_magic_escape():
     check_transform(ipt2.EscapedCommand, MULTILINE_MAGIC)
     check_transform(ipt2.EscapedCommand, INDENTED_MAGIC)
 
 def test_find_autocalls():
     for case in [AUTOCALL_QUOTE, AUTOCALL_QUOTE2, AUTOCALL_PAREN]:
         print("Testing %r" % case[0])
         check_find(ipt2.EscapedCommand, case)
 
 def test_transform_autocall():
     for case in [AUTOCALL_QUOTE, AUTOCALL_QUOTE2, AUTOCALL_PAREN]:
         print("Testing %r" % case[0])
         check_transform(ipt2.EscapedCommand, case)
 
 def test_find_help():
     for case in [SIMPLE_HELP, DETAILED_HELP, MAGIC_HELP, HELP_IN_EXPR]:
         check_find(ipt2.HelpEnd, case)
 
     tf = check_find(ipt2.HelpEnd, HELP_CONTINUED_LINE)
     nt.assert_equal(tf.q_line, 1)
     nt.assert_equal(tf.q_col, 3)
 
     tf = check_find(ipt2.HelpEnd, HELP_MULTILINE)
     nt.assert_equal(tf.q_line, 1)
     nt.assert_equal(tf.q_col, 8)
 
     # ? in a comment does not trigger help
     check_find(ipt2.HelpEnd, (["foo # bar?\n"], None, None), match=False)
     # Nor in a string
     check_find(ipt2.HelpEnd, (["foo = '''bar?\n"], None, None), match=False)
 
 def test_transform_help():
     tf = ipt2.HelpEnd((1, 0), (1, 9))
     nt.assert_equal(tf.transform(HELP_IN_EXPR[0]), HELP_IN_EXPR[2])
 
     tf = ipt2.HelpEnd((1, 0), (2, 3))
     nt.assert_equal(tf.transform(HELP_CONTINUED_LINE[0]), HELP_CONTINUED_LINE[2])
 
     tf = ipt2.HelpEnd((1, 0), (2, 8))
     nt.assert_equal(tf.transform(HELP_MULTILINE[0]), HELP_MULTILINE[2])
 
 def test_check_complete():
     cc = ipt2.TransformerManager().check_complete
     nt.assert_equal(cc("a = 1"), ('complete', None))
     nt.assert_equal(cc("for a in range(5):"), ('incomplete', 4))
     nt.assert_equal(cc("raise = 2"), ('invalid', None))
     nt.assert_equal(cc("a = [1,\n2,"), ('incomplete', 0))
     nt.assert_equal(cc(")"), ('incomplete', 0))
     nt.assert_equal(cc("\\\r\n"), ('incomplete', 0))
     nt.assert_equal(cc("a = '''\n   hi"), ('incomplete', 3))
     nt.assert_equal(cc("def a():\n x=1\n global x"), ('invalid', None))
     nt.assert_equal(cc("a \\ "), ('invalid', None))  # Nothing allowed after backslash
 
     # no need to loop on all the letters/numbers.
     short = '12abAB'+string.printable[62:]
     for c in short:
         # test does not raise:
         cc(c)
         for k in short:
             cc(c+k)
 
+def test_null_cleanup_transformer():
+    manager = ipt2.TransformerManager()
+    manager.cleanup_transforms.insert(0, null_cleanup_transformer)
+    nt.assert_is(manager.transform_cell(""), "")