"""This module tests SyntaxErrors. Here's an example of the sort of thing that is tested. >>> def f(x): ... global x Traceback (most recent call last): SyntaxError: name 'x' is local and global The tests are all raise SyntaxErrors. They were created by checking each C call that raises SyntaxError. There are several modules that raise these exceptions-- ast.c, compile.c, future.c, pythonrun.c, and symtable.c. The parser itself outlaws a lot of invalid syntax. None of these errors are tested here at the moment. We should add some tests; since there are infinitely many programs with invalid syntax, we would need to be judicious in selecting some. The compiler generates a synthetic module name for code executed by doctest. Since all the code comes from the same module, a suffix like [1] is appended to the module name, As a consequence, changing the order of tests in this module means renumbering all the errors after it. (Maybe we should enable the ellipsis option for these tests.) In ast.c, syntax errors are raised by calling ast_error(). Errors from set_context(): TODO(jhylton): "assignment to None" is inconsistent with other messages >>> obj.None = 1 Traceback (most recent call last): SyntaxError: assignment to None (, line 1) >>> None = 1 Traceback (most recent call last): SyntaxError: assignment to None (, line 1) It's a syntax error to assign to the empty tuple. Why isn't it an error to assign to the empty list? It will always raise some error at runtime. >>> () = 1 Traceback (most recent call last): SyntaxError: can't assign to () (, line 1) >>> f() = 1 Traceback (most recent call last): SyntaxError: can't assign to function call (, line 1) >>> del f() Traceback (most recent call last): SyntaxError: can't delete function call (, line 1) >>> a + 1 = 2 Traceback (most recent call last): SyntaxError: can't assign to operator (, line 1) >>> (x for x in x) = 1 Traceback (most recent call last): SyntaxError: can't assign to generator expression (, line 1) >>> 1 = 1 Traceback (most recent call last): SyntaxError: can't assign to literal (, line 1) >>> "abc" = 1 Traceback (most recent call last): SyntaxError: can't assign to literal (, line 1) >>> `1` = 1 Traceback (most recent call last): SyntaxError: can't assign to repr (, line 1) If the left-hand side of an assignment is a list or tuple, an illegal expression inside that contain should still cause a syntax error. This test just checks a couple of cases rather than enumerating all of them. >>> (a, "b", c) = (1, 2, 3) Traceback (most recent call last): SyntaxError: can't assign to literal (, line 1) >>> [a, b, c + 1] = [1, 2, 3] Traceback (most recent call last): SyntaxError: can't assign to operator (, line 1) >>> a if 1 else b = 1 Traceback (most recent call last): SyntaxError: can't assign to conditional expression (, line 1) From compiler_complex_args(): >>> def f(None=1): ... pass Traceback (most recent call last): SyntaxError: assignment to None (, line 1) From ast_for_arguments(): >>> def f(x, y=1, z): ... pass Traceback (most recent call last): SyntaxError: non-default argument follows default argument (, line 1) >>> def f(x, None): ... pass Traceback (most recent call last): SyntaxError: assignment to None (, line 1) >>> def f(*None): ... pass Traceback (most recent call last): SyntaxError: assignment to None (, line 1) >>> def f(**None): ... pass Traceback (most recent call last): SyntaxError: assignment to None (, line 1) From ast_for_funcdef(): >>> def None(x): ... pass Traceback (most recent call last): SyntaxError: assignment to None (, line 1) From ast_for_call(): >>> def f(it, *varargs): ... return list(it) >>> L = range(10) >>> f(x for x in L) [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] >>> f(x for x in L, 1) Traceback (most recent call last): SyntaxError: Generator expression must be parenthesized if not sole argument (, line 1) >>> f((x for x in L), 1) [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] >>> f(i0, i1, i2, i3, i4, i5, i6, i7, i8, i9, i10, i11, ... i12, i13, i14, i15, i16, i17, i18, i19, i20, i21, i22, ... i23, i24, i25, i26, i27, i28, i29, i30, i31, i32, i33, ... i34, i35, i36, i37, i38, i39, i40, i41, i42, i43, i44, ... i45, i46, i47, i48, i49, i50, i51, i52, i53, i54, i55, ... i56, i57, i58, i59, i60, i61, i62, i63, i64, i65, i66, ... i67, i68, i69, i70, i71, i72, i73, i74, i75, i76, i77, ... i78, i79, i80, i81, i82, i83, i84, i85, i86, i87, i88, ... i89, i90, i91, i92, i93, i94, i95, i96, i97, i98, i99, ... i100, i101, i102, i103, i104, i105, i106, i107, i108, ... i109, i110, i111, i112, i113, i114, i115, i116, i117, ... i118, i119, i120, i121, i122, i123, i124, i125, i126, ... i127, i128, i129, i130, i131, i132, i133, i134, i135, ... i136, i137, i138, i139, i140, i141, i142, i143, i144, ... i145, i146, i147, i148, i149, i150, i151, i152, i153, ... i154, i155, i156, i157, i158, i159, i160, i161, i162, ... i163, i164, i165, i166, i167, i168, i169, i170, i171, ... i172, i173, i174, i175, i176, i177, i178, i179, i180, ... i181, i182, i183, i184, i185, i186, i187, i188, i189, ... i190, i191, i192, i193, i194, i195, i196, i197, i198, ... i199, i200, i201, i202, i203, i204, i205, i206, i207, ... i208, i209, i210, i211, i212, i213, i214, i215, i216, ... i217, i218, i219, i220, i221, i222, i223, i224, i225, ... i226, i227, i228, i229, i230, i231, i232, i233, i234, ... i235, i236, i237, i238, i239, i240, i241, i242, i243, ... i244, i245, i246, i247, i248, i249, i250, i251, i252, ... i253, i254, i255) Traceback (most recent call last): SyntaxError: more than 255 arguments (, line 1) The actual error cases counts positional arguments, keyword arguments, and generator expression arguments separately. This test combines the three. >>> f(i0, i1, i2, i3, i4, i5, i6, i7, i8, i9, i10, i11, ... i12, i13, i14, i15, i16, i17, i18, i19, i20, i21, i22, ... i23, i24, i25, i26, i27, i28, i29, i30, i31, i32, i33, ... i34, i35, i36, i37, i38, i39, i40, i41, i42, i43, i44, ... i45, i46, i47, i48, i49, i50, i51, i52, i53, i54, i55, ... i56, i57, i58, i59, i60, i61, i62, i63, i64, i65, i66, ... i67, i68, i69, i70, i71, i72, i73, i74, i75, i76, i77, ... i78, i79, i80, i81, i82, i83, i84, i85, i86, i87, i88, ... i89, i90, i91, i92, i93, i94, i95, i96, i97, i98, i99, ... i100, i101, i102, i103, i104, i105, i106, i107, i108, ... i109, i110, i111, i112, i113, i114, i115, i116, i117, ... i118, i119, i120, i121, i122, i123, i124, i125, i126, ... i127, i128, i129, i130, i131, i132, i133, i134, i135, ... i136, i137, i138, i139, i140, i141, i142, i143, i144, ... i145, i146, i147, i148, i149, i150, i151, i152, i153, ... i154, i155, i156, i157, i158, i159, i160, i161, i162, ... i163, i164, i165, i166, i167, i168, i169, i170, i171, ... i172, i173, i174, i175, i176, i177, i178, i179, i180, ... i181, i182, i183, i184, i185, i186, i187, i188, i189, ... i190, i191, i192, i193, i194, i195, i196, i197, i198, ... i199, i200, i201, i202, i203, i204, i205, i206, i207, ... i208, i209, i210, i211, i212, i213, i214, i215, i216, ... i217, i218, i219, i220, i221, i222, i223, i224, i225, ... i226, i227, i228, i229, i230, i231, i232, i233, i234, ... i235, i236, i237, i238, i239, i240, i241, i242, i243, ... (x for x in i244), i245, i246, i247, i248, i249, i250, i251, ... i252=1, i253=1, i254=1, i255=1) Traceback (most recent call last): SyntaxError: more than 255 arguments (, line 1) >>> f(lambda x: x[0] = 3) Traceback (most recent call last): SyntaxError: lambda cannot contain assignment (, line 1) The grammar accepts any test (basically, any expression) in the keyword slot of a call site. Test a few different options. >>> f(x()=2) Traceback (most recent call last): SyntaxError: keyword can't be an expression (, line 1) >>> f(a or b=1) Traceback (most recent call last): SyntaxError: keyword can't be an expression (, line 1) >>> f(x.y=1) Traceback (most recent call last): SyntaxError: keyword can't be an expression (, line 1) From ast_for_expr_stmt(): >>> (x for x in x) += 1 Traceback (most recent call last): SyntaxError: augmented assignment to generator expression not possible (, line 1) >>> None += 1 Traceback (most recent call last): SyntaxError: assignment to None (, line 1) >>> f() += 1 Traceback (most recent call last): SyntaxError: illegal expression for augmented assignment (, line 1) Test continue in finally in weird combinations. continue in for loop under finally shouuld be ok. >>> def test(): ... try: ... pass ... finally: ... for abc in range(10): ... continue ... print abc >>> test() 9 Start simple, a continue in a finally should not be allowed. >>> def test(): ... for abc in range(10): ... try: ... pass ... finally: ... continue ... Traceback (most recent call last): ... SyntaxError: 'continue' not supported inside 'finally' clause (, line 6) This is essentially a continue in a finally which should not be allowed. >>> def test(): ... for abc in range(10): ... try: ... pass ... finally: ... try: ... continue ... except: ... pass Traceback (most recent call last): ... SyntaxError: 'continue' not supported inside 'finally' clause (, line 7) >>> def foo(): ... try: ... pass ... finally: ... continue Traceback (most recent call last): ... SyntaxError: 'continue' not supported inside 'finally' clause (, line 5) >>> def foo(): ... for a in (): ... try: pass ... finally: continue Traceback (most recent call last): ... SyntaxError: 'continue' not supported inside 'finally' clause (, line 4) >>> def foo(): ... for a in (): ... try: pass ... finally: ... try: ... continue ... finally: pass Traceback (most recent call last): ... SyntaxError: 'continue' not supported inside 'finally' clause (, line 6) >>> def foo(): ... for a in (): ... try: pass ... finally: ... try: ... pass ... except: ... continue Traceback (most recent call last): ... SyntaxError: 'continue' not supported inside 'finally' clause (, line 8) """ import re import unittest import warnings from test import test_support class SyntaxTestCase(unittest.TestCase): def _check_error(self, code, errtext, filename="", mode="exec", subclass=None): """Check that compiling code raises SyntaxError with errtext. errtest is a regular expression that must be present in the test of the exception raised. If subclass is specified it is the expected subclass of SyntaxError (e.g. IndentationError). """ try: compile(code, filename, mode) except SyntaxError, err: if subclass and not isinstance(err, subclass): self.fail("SyntaxError is not a %s" % subclass.__name__) mo = re.search(errtext, str(err)) if mo is None: self.fail("SyntaxError did not contain '%r'" % (errtext,)) else: self.fail("compile() did not raise SyntaxError") def test_assign_call(self): self._check_error("f() = 1", "assign") def test_assign_del(self): self._check_error("del f()", "delete") def test_global_err_then_warn(self): # Bug tickler: The SyntaxError raised for one global statement # shouldn't be clobbered by a SyntaxWarning issued for a later one. source = re.sub('(?m)^ *:', '', """\ :def error(a): : global a # SyntaxError :def warning(): : b = 1 : global b # SyntaxWarning :""") warnings.filterwarnings(action='ignore', category=SyntaxWarning) self._check_error(source, "global") warnings.filters.pop(0) def test_break_outside_loop(self): self._check_error("break", "outside loop") def test_delete_deref(self): source = re.sub('(?m)^ *:', '', """\ :def foo(x): : def bar(): : print x : del x :""") self._check_error(source, "nested scope") def test_unexpected_indent(self): self._check_error("foo()\n bar()\n", "unexpected indent", subclass=IndentationError) def test_no_indent(self): self._check_error("if 1:\nfoo()", "expected an indented block", subclass=IndentationError) def test_bad_outdent(self): self._check_error("if 1:\n foo()\n bar()", "unindent does not match .* level", subclass=IndentationError) def test_kwargs_last(self): self._check_error("int(base=10, '2')", "non-keyword arg") def test_main(): test_support.run_unittest(SyntaxTestCase) from test import test_syntax test_support.run_doctest(test_syntax, verbosity=True) if __name__ == "__main__": test_main()