[PATCH v2 4/4] tests/functional/test_vmstate: Test whether the checker script works as expected

[Thomas Huth <thuth@redhat.com>]

From: Thomas Huth <thuth@redhat.com>

We've got two vmstate dump files in the repository which are meant
for verifying whether the vmstate-static-checker.py works as expected.
Since running this manually is a cumbersome job, let's add an automated
test for this instead that runs the script with the two dump files
and checks for the expected output.

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 tests/functional/test_vmstate.py | 37 ++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/tests/functional/test_vmstate.py b/tests/functional/test_vmstate.py
index cc988987481..19a62e8a17e 100755
--- a/tests/functional/test_vmstate.py
+++ b/tests/functional/test_vmstate.py
@@ -9,6 +9,22 @@
 from qemu_test import QemuSystemTest
 
 
+expected_output='''Warning: checking incompatible machine types: "pc-i440fx-2.1", "pc-i440fx-2.2"
+Section "fw_cfg" does not exist in dest
+Section "fusbh200-ehci-usb" version error: 2 > 1
+Section "fusbh200-ehci-usb", Description "ehci-core": expected field "usbsts", got "usbsts_pending"; skipping rest
+Section "pci-serial-4x" Description "pci-serial-multi": Entry "Fields" missing
+Section "intel-hda-generic", Description "intel-hda", Field "pci": missing description
+Section "cfi.pflash01": Entry "Description" missing
+Section "megasas", Description "PCIDevice": expected field "irq_state", while dest has no further fields
+Section "PIIX3-xen" Description "PIIX3": minimum version error: 1 < 2
+Section "PIIX3-xen" Description "PIIX3": Entry "Subsections" missing
+Section "tpci200": Description "tpci200" missing, got "tpci2002" instead; skipping
+Section "sun-fdtwo" Description "fdc": version error: 2 > 1
+Section "sun-fdtwo", Description "fdrive": Subsection "fdrive/media_rate" not found
+Section "usb-kbd" Description "usb-kbd" Field "kbd.keycodes" size mismatch: 4 , 2
+'''
+
 class VmStateTest(QemuSystemTest):
 
     def run_vmstate_checker(self, src_json, dst_json):
@@ -19,6 +35,27 @@ def run_vmstate_checker(self, src_json, dst_json):
                               stderr=subprocess.STDOUT,
                               text=True)
 
+    def test_checker(self):
+        """
+        Test whether the checker script correctly detects the changes
+        between dump1.json and dump2.json.
+        """
+        if self.arch != 'x86_64':
+            self.skipTest('for x86 only')
+        src_json = self.data_file('..', 'data', 'vmstate-static-checker',
+                                  'dump1.json')
+        dst_json = self.data_file('..', 'data', 'vmstate-static-checker',
+                                  'dump2.json')
+        self.log.info(f'Comparing {src_json} with {dst_json}')
+        cp = self.run_vmstate_checker(src_json, dst_json)
+        if cp.returncode != 13:
+            self.fail('Unexpected return code of vmstate-static-checker: ' +
+                      cp.returncode)
+        if cp.stdout != expected_output:
+            self.log.info('vmstate-static-checker output:\n' + cp.stdout)
+            self.log.info('expected output:\n' + expected_output)
+            self.fail('Unexpected vmstate-static-checker output!')
+
     def test_vmstate(self):
         target_machine = {
             'aarch64': 'virt-7.2',
-- 
2.49.0