support/testing: infra: add assertRunNotOk()

There are a number of runtime tests that checks that a command fails as
expected, so add an assertRunNotOk() similar to the existing assertRunOk()
to handle that instead of open coding it everywhere.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Reviewed-by: Fiona Klute <fiona.klute@gmx.de>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

support/testing/infra/basetest.py

@@ -150,3 +150,14 @@ class BRTest(BRConfigTest):
             0,
             "\nFailed to run: {}\noutput was:\n{}".format(cmd, '  '+'\n  '.join(out))
         )
+
+    # Run the given 'cmd' with a 'timeout' on the target and
+    # assert that the command fails; on success, print the
+    # faulty command and its output
+    def assertRunNotOk(self, cmd, timeout=-1):
+        out, exit_code = self.emulator.run(cmd, timeout)
+        self.assertNotEqual(
+            exit_code,
+            0,
+            "\nUnexpected success: {}\noutput was:\n{}".format(cmd, '  '+'\n  '.join(out))
+        )