Re: Re: [PATCH 03/10] scripts: Add 'qemu-qmp-replies-tool' script for testing and modifying data for qemucapabilitiestest

On Fri, Jan 26, 2024 at 09:30:29AM +0100, Peter Krempa wrote: > On Thu, Jan 25, 2024 at 09:06:54 -0800, Andrea Bolognani wrote: > > I've never seen the 'raise Foo() from None' pattern though. Can you > > explain why it's needed here? > > Python would re-raise the original exception along with the new one > without that. I guess it doesn't hurt to have it there, but it doesn't seem very useful either: $ git diff diff --git a/scripts/qemu-replies-tool.py b/scripts/qemu-replies-tool.py index 9ab1c30ee2..bde6b2dad5 100755 --- a/scripts/qemu-replies-tool.py +++ b/scripts/qemu-replies-tool.py @@ -46,7 +46,7 @@ def qemu_replies_load(filename): jsonstr = '' except json.decoder.JSONDecodeError as je: - raise qrtException("JSON error:\n'%s'\nwhile processing snippet:\n'%s'" % (je, jsonstr)) from None + raise qrtException("JSON error:\n'%s'\nwhile processing snippet:\n'%s'" % (je, jsonstr)) if command is not None or jsonstr != '': if command is not None: diff --git a/tests/qemucapabilitiesdata/caps_8.2.0_x86_64.replies b/tests/qemucapabilitiesdata/caps_8.2.0_x86_64.replies index cc2190dfd3..cf1425e0bb 100644 --- a/tests/qemucapabilitiesdata/caps_8.2.0_x86_64.replies +++ b/tests/qemucapabilitiesdata/caps_8.2.0_x86_64.replies @@ -1,5 +1,5 @@ { - "execute": "qmp_capabilities", + "execute": } "qmp_capabilities", "id": "libvirt-1" } $ ./scripts/qemu-replies-tool.py tests/qemucapabilitiesdata/caps_8.2.0_x86_64.replies 'tests/qemucapabilitiesdata/caps_8.2.0_x86_64.replies' ... FAIL JSON error: 'Expecting value: line 2 column 14 (char 15)' while processing snippet: '{ "execute": } "qmp_capabilities", "id": "libvirt-1" } ' The behavior without it is just the same AFAICT.