bpo-43859: Improve the error message for IndentationError exceptions (GH-25431)

1 files changed, 132 insertions, 0 deletions

diff --git a/Lib/test/test_syntax.py b/Lib/test/test_syntax.py
index 5f622b092f9..dc81964830a 100644
--- a/Lib/test/test_syntax.py
+++ b/Lib/test/test_syntax.py
@@ -926,6 +926,138 @@ Incomplete dictionary literals
    Traceback (most recent call last):
    SyntaxError: invalid syntax
 
+Specialized indentation errors:
+
+   >>> while condition:
+   ... pass
+   Traceback (most recent call last):
+   IndentationError: expected an indented block after 'while' statement on line 1
+
+   >>> for x in range(10):
+   ... pass
+   Traceback (most recent call last):
+   IndentationError: expected an indented block after 'for' statement on line 1
+
+   >>> for x in range(10):
+   ...     pass
+   ... else:
+   ... pass
+   Traceback (most recent call last):
+   IndentationError: expected an indented block after 'else' statement on line 3
+
+   >>> async for x in range(10):
+   ... pass
+   Traceback (most recent call last):
+   IndentationError: expected an indented block after 'for' statement on line 1
+
+   >>> async for x in range(10):
+   ...     pass
+   ... else:
+   ... pass
+   Traceback (most recent call last):
+   IndentationError: expected an indented block after 'else' statement on line 3
+
+   >>> if something:
+   ... pass
+   Traceback (most recent call last):
+   IndentationError: expected an indented block after 'if' statement on line 1
+
+   >>> if something:
+   ...     pass
+   ... elif something_else:
+   ... pass
+   Traceback (most recent call last):
+   IndentationError: expected an indented block after 'elif' statement on line 3
+
+   >>> if something:
+   ...     pass
+   ... elif something_else:
+   ...     pass
+   ... else:
+   ... pass
+   Traceback (most recent call last):
+   IndentationError: expected an indented block after 'else' statement on line 5
+
+   >>> try:
+   ... pass
+   Traceback (most recent call last):
+   IndentationError: expected an indented block after 'try' statement on line 1
+
+   >>> try:
+   ...     something()
+   ... except A:
+   ... pass
+   Traceback (most recent call last):
+   IndentationError: expected an indented block after 'except' statement on line 3
+
+   >>> try:
+   ...     something()
+   ... except A:
+   ...     pass
+   ... finally:
+   ... pass
+   Traceback (most recent call last):
+   IndentationError: expected an indented block after 'finally' statement on line 5
+
+   >>> with A:
+   ... pass
+   Traceback (most recent call last):
+   IndentationError: expected an indented block after 'with' statement on line 1
+
+   >>> with A as a, B as b:
+   ... pass
+   Traceback (most recent call last):
+   IndentationError: expected an indented block after 'with' statement on line 1
+
+   >>> with (A as a, B as b):
+   ... pass
+   Traceback (most recent call last):
+   IndentationError: expected an indented block after 'with' statement on line 1
+
+   >>> async with A:
+   ... pass
+   Traceback (most recent call last):
+   IndentationError: expected an indented block after 'with' statement on line 1
+
+   >>> async with A as a, B as b:
+   ... pass
+   Traceback (most recent call last):
+   IndentationError: expected an indented block after 'with' statement on line 1
+
+   >>> async with (A as a, B as b):
+   ... pass
+   Traceback (most recent call last):
+   IndentationError: expected an indented block after 'with' statement on line 1
+
+   >>> def foo(x, /, y, *, z=2):
+   ... pass
+   Traceback (most recent call last):
+   IndentationError: expected an indented block after function definition on line 1
+
+   >>> class Blech(A):
+   ... pass
+   Traceback (most recent call last):
+   IndentationError: expected an indented block after class definition on line 1
+
+   >>> match something:
+   ... pass
+   Traceback (most recent call last):
+   IndentationError: expected an indented block after 'match' statement on line 1
+
+   >>> match something:
+   ...     case []:
+   ... pass
+   Traceback (most recent call last):
+   IndentationError: expected an indented block after 'case' statement on line 2
+
+   >>> match something:
+   ...     case []:
+   ...         ...
+   ...     case {}:
+   ... pass
+   Traceback (most recent call last):
+   IndentationError: expected an indented block after 'case' statement on line 4
+
 Make sure that the old "raise X, Y[, Z]" form is gone:
    >>> raise X, Y
    Traceback (most recent call last):