test_ok1/changelog/4984.bugfix.rst

Fixed an internal error crash with ``IndexError: list index out of range`` when
collecting a module which starts with a decorated function, the decorator
raises, and assertion rewriting is enabled.
assertion/rewrite: fix internal error on collection error due to decorated function For decorated functions, the lineno of the FunctionDef AST node points to the `def` line, not to the first decorator line. On the other hand, in code objects, the `co_firstlineno` points to the first decorator line. Assertion rewriting inserts some imports to code it rewrites. The imports are inserted at the lineno of the first statement in the AST. In turn, the code object compiled from the rewritten AST uses the lineno of the first statement (which is the first inserted import). This means that given a module like this, ```py @foo @bar def baz(): pass ``` the lineno of the code object without assertion rewriting (`--assertion=plain`) is 1, but with assertion rewriting it is 3. And this causes some issues for the exception repr when e.g. the decorator line is invalid and raises during collection. The code becomes confused and crashes with INTERNALERROR> File "_pytest/_code/code.py", line 638, in get_source INTERNALERROR> lines.append(space_prefix + source.lines[line_index].strip()) INTERNALERROR> IndexError: list index out of range Fix it by special casing decorators. Maybe there are other cases like this but off hand I can't think of another Python construct where the lineno of the item would be after its first line, and this is the only such issue we have had reported. 2020-09-13 03:28:19 +08:00			Fixed an internal error crash with ``IndexError: list index out of range`` when
			`collecting a module which starts with a decorated function, the decorator`
			`raises, and assertion rewriting is enabled.`