IPython/core/tests/test_inputsplitter.py

"""Tests for the inputsplitter module.
"""
#-----------------------------------------------------------------------------
#  Copyright (C) 2010  The IPython Development Team
#
#  Distributed under the terms of the BSD License.  The full license is in
#  the file COPYING, distributed as part of this software.
#-----------------------------------------------------------------------------

#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
# stdlib
import unittest

# Third party
import nose.tools as nt

# Our own
from IPython.core import inputsplitter as isp

#-----------------------------------------------------------------------------
# Semi-complete examples (also used as tests)
#-----------------------------------------------------------------------------
def mini_interactive_loop(raw_input):
    """Minimal example of the logic of an interactive interpreter loop.

    This serves as an example, and it is used by the test system with a fake
    raw_input that simulates interactive input."""

    from IPython.core.inputsplitter import InputSplitter
    
    isp = InputSplitter()
    # In practice, this input loop would be wrapped in an outside loop to read
    # input indefinitely, until some exit/quit command was issued.  Here we
    # only illustrate the basic inner loop.
    while isp.push_accepts_more():
        indent = ' '*isp.indent_spaces
        prompt = '>>> ' + indent
        line = indent + raw_input(prompt)
        isp.push(line)

    # Here we just return input so we can use it in a test suite, but a real
    # interpreter would instead send it for execution somewhere.
    src = isp.source_reset()
    print 'Input source was:\n', src
    return src

#-----------------------------------------------------------------------------
# Test utilities, just for local use
#-----------------------------------------------------------------------------

def assemble(block):
    """Assemble a block into multi-line sub-blocks."""
    return ['\n'.join(sub_block)+'\n' for sub_block in block]


def pseudo_input(lines):
    """Return a function that acts like raw_input but feeds the input list."""
    ilines = iter(lines)
    def raw_in(prompt):
        try:
            return next(ilines)
        except StopIteration:
            return ''
    return raw_in

#-----------------------------------------------------------------------------
# Tests
#-----------------------------------------------------------------------------
def test_spaces():
    tests = [('', 0),
             (' ', 1),
             ('\n', 0),
             (' \n', 1),
             ('x', 0),
             (' x', 1),
             ('  x',2),
             ('    x',4),
             # Note: tabs are counted as a single whitespace!
             ('\tx', 1),
             ('\t x', 2),
             ]
    
    for s, nsp in tests:
        nt.assert_equal(isp.num_ini_spaces(s), nsp)


def test_remove_comments():
    tests = [('text', 'text'),
             ('text # comment', 'text '),
             ('text # comment\n', 'text \n'),
             ('text # comment \n', 'text \n'),
             ('line # c \nline\n','line \nline\n'),
             ('line # c \nline#c2  \nline\nline #c\n\n',
              'line \nline\nline\nline \n\n'),
             ]

    for inp, out in tests:
        nt.assert_equal(isp.remove_comments(inp), out)


def test_get_input_encoding():
    encoding = isp.get_input_encoding()
    nt.assert_true(isinstance(encoding, basestring))
    # simple-minded check that at least encoding a simple string works with the
    # encoding we got.
    nt.assert_equal('test'.encode(encoding), 'test')


class InputSplitterTestCase(unittest.TestCase):
    def setUp(self):
        self.isp = isp.InputSplitter()

    def test_reset(self):
        isp = self.isp
        isp.push('x=1')
        isp.reset()
        self.assertEqual(isp._buffer, [])
        self.assertEqual(isp.indent_spaces, 0)
        self.assertEqual(isp.source, '')
        self.assertEqual(isp.code, None)
        self.assertEqual(isp._is_complete, False)

    def test_source(self):
        self.isp._store('1')
        self.isp._store('2')
        self.assertEqual(self.isp.source, '1\n2\n')
        self.assertTrue(len(self.isp._buffer)>0)
        self.assertEqual(self.isp.source_reset(), '1\n2\n')
        self.assertEqual(self.isp._buffer, [])
        self.assertEqual(self.isp.source, '')
        
    def test_indent(self):
        isp = self.isp # shorthand
        isp.push('x=1')
        self.assertEqual(isp.indent_spaces, 0)
        isp.push('if 1:\n    x=1')
        self.assertEqual(isp.indent_spaces, 4)
        isp.push('y=2\n')
        self.assertEqual(isp.indent_spaces, 0)
        isp.push('if 1:')
        self.assertEqual(isp.indent_spaces, 4)
        isp.push('    x=1')
        self.assertEqual(isp.indent_spaces, 4)
        # Blank lines shouldn't change the indent level
        isp.push(' '*2)
        self.assertEqual(isp.indent_spaces, 4)

    def test_indent2(self):
        isp = self.isp
        # When a multiline statement contains parens or multiline strings, we
        # shouldn't get confused.
        isp.push("if 1:")
        isp.push("    x = (1+\n    2)")
        self.assertEqual(isp.indent_spaces, 4)

    def test_dedent(self):
        isp = self.isp # shorthand
        isp.push('if 1:')
        self.assertEqual(isp.indent_spaces, 4)
        isp.push('    pass')
        self.assertEqual(isp.indent_spaces, 0)
        
    def test_push(self):
        isp = self.isp
        self.assertTrue(isp.push('x=1'))

    def test_push2(self):
        isp = self.isp
        self.assertFalse(isp.push('if 1:'))
        for line in ['  x=1', '# a comment', '  y=2']:
            self.assertTrue(isp.push(line))
            
    def test_push3(self):
        """Test input with leading whitespace"""
        isp = self.isp
        isp.push('  x=1')
        isp.push('  y=2')
        self.assertEqual(isp.source, 'if 1:\n  x=1\n  y=2\n')

    def test_replace_mode(self):
        isp = self.isp
        isp.input_mode = 'replace'
        isp.push('x=1')
        self.assertEqual(isp.source, 'x=1\n')
        isp.push('x=2')
        self.assertEqual(isp.source, 'x=2\n')

    def test_push_accepts_more(self):
        isp = self.isp
        isp.push('x=1')
        self.assertFalse(isp.push_accepts_more())

    def test_push_accepts_more2(self):
        isp = self.isp
        isp.push('if 1:')
        self.assertTrue(isp.push_accepts_more())
        isp.push('  x=1')
        self.assertTrue(isp.push_accepts_more())
        isp.push('')
        self.assertFalse(isp.push_accepts_more())
        
    def test_push_accepts_more3(self):
        isp = self.isp
        isp.push("x = (2+\n3)")
        self.assertFalse(isp.push_accepts_more())

    def test_push_accepts_more4(self):
        isp = self.isp
        # When a multiline statement contains parens or multiline strings, we
        # shouldn't get confused.
        # FIXME: we should be able to better handle de-dents in statements like
        # multiline strings and multiline expressions (continued with \ or
        # parens).  Right now we aren't handling the indentation tracking quite
        # correctly with this, though in practice it may not be too much of a
        # problem.  We'll need to see.
        isp.push("if 1:")
        isp.push("    x = (2+")
        isp.push("    3)")
        self.assertTrue(isp.push_accepts_more())
        isp.push("    y = 3")
        self.assertTrue(isp.push_accepts_more())
        isp.push('')
        self.assertFalse(isp.push_accepts_more())

    def test_syntax_error(self):
        isp = self.isp
        # Syntax errors immediately produce a 'ready' block, so the invalid
        # Python can be sent to the kernel for evaluation with possible ipython
        # special-syntax conversion.
        isp.push('run foo')
        self.assertFalse(isp.push_accepts_more())

    def check_split(self, block_lines, compile=True):
        blocks = assemble(block_lines)
        lines = ''.join(blocks)
        oblock = self.isp.split_blocks(lines)
        self.assertEqual(oblock, blocks)
        if compile:
            for block in blocks:
                self.isp._compile(block)

    def test_split(self):
        # All blocks of input we want to test in a list.  The format for each
        # block is a list of lists, with each inner lists consisting of all the
        # lines (as single-lines) that should make up a sub-block.

        # Note: do NOT put here sub-blocks that don't compile, as the
        # check_split() routine makes a final verification pass to check that
        # each sub_block, as returned by split_blocks(), does compile
        # correctly.
        all_blocks = [ [['x=1']],

                       [['x=1'],
                        ['y=2']],

                       [['x=1'],
                        ['# a comment'],
                        ['y=11']],

                       [['if 1:',
                         '  x=1'],
                        ['y=3']],

                       [['def f(x):',
                         '  return x'],
                        ['x=1']],

                       [['def f(x):',
                         '  x+=1',
                         '  ',
                         '  return x'],
                        ['x=1']],

                       [['def f(x):',
                         '  if x>0:',
                         '    y=1',
                         '  # a comment',
                         '  else:',
                         '    y=4',
                         ' ',
                         '  return y'],
                        ['x=1'],
                        ['if 1:',
                         '  y=11'] ],
                       
                       [['for i in range(10):'
                         '  x=i**2']],

                       [['for i in range(10):'
                         '  x=i**2'],
                        ['z = 1']],
                       ]
        for block_lines in all_blocks:
            self.check_split(block_lines)
        
    def test_split_syntax_errors(self):
        # Block splitting with invalid syntax
        all_blocks = [ [['a syntax error']],
            
                       [['x=1'],
                        ['a syntax error']],

                       [['for i in range(10):'
                         '  an error']],
                       
                       ]
        for block_lines in all_blocks:
            self.check_split(block_lines, compile=False)


class InteractiveLoopTestCase(unittest.TestCase):
    """Tests for an interactive loop like a python shell.
    """
    def check_ns(self, lines, ns):
        """Validate that the given input lines produce the resulting namespace.

        Note: the input lines are given exactly as they would be typed in an
        auto-indenting environment, as mini_interactive_loop above already does
        auto-indenting and prepends spaces to the input.
        """
        src = mini_interactive_loop(pseudo_input(lines))
        test_ns = {}
        exec src in test_ns
        # We can't check that the provided ns is identical to the test_ns,
        # because Python fills test_ns with extra keys (copyright, etc).  But
        # we can check that the given dict is *contained* in test_ns
        for k,v in ns.items():
            self.assertEqual(test_ns[k], v)
        
    def test_simple(self):
        self.check_ns(['x=1'], dict(x=1))

    def test_simple2(self):
        self.check_ns(['if 1:', 'x=2'], dict(x=2))

    def test_xy(self):
        self.check_ns(['x=1; y=2'], dict(x=1, y=2))

    def test_abc(self):
        self.check_ns(['if 1:','a=1','b=2','c=3'], dict(a=1, b=2, c=3))
    
    def test_multi(self):
        self.check_ns(['x =(1+','1+','2)'], dict(x=4))