behave: new test for dnf4 chroot without bootstrap

Relates: #1476

behave/features/dnf4.feature

@@ -0,0 +1,8 @@
+Feature: Mock is able to work with dnf4 chroots
+
+    @dnf4
+    Scenario: Building a DNF4 chroot without bootstrap chroot
+        Given an unique mock namespace
+        And mock is always executed with "--no-bootstrap-chroot"
+        When an online source RPM is rebuilt against centos-stream+epel-9-x86_64
+        Then the build succeeds

behave/features/steps/other.py

@@ -169,11 +169,19 @@ def step_impl(context, expected_message):
     assert_that(err[0], contains_string(expected_message))
 
 
+def _rebuild_online(context, chroot=None):
+    url = context.test_storage + "mock-test-bump-version-1-0.src.rpm"
+    context.mock.rebuild([url], chroot)
+
+
 @when('an online source RPM is rebuilt')
 def step_impl(context):
-    url = context.test_storage + "mock-test-bump-version-1-0.src.rpm"
-    context.mock.rebuild([url])
+    _rebuild_online(context)
+
 
+@when('an online source RPM is rebuilt against {chroot}')
+def step_impl(context, chroot):
+    _rebuild_online(context, chroot)
 
 @then('{output} contains "{text}"')
 def step_impl(context, output, text):

behave/testlib.py

@@ -97,11 +97,14 @@ def init(self):
         }]
         return out, err
 
-    def rebuild(self, srpms):
+    def rebuild(self, srpms, chroot=None):
         """ Rebuild source RPM(s) """
 
         chrootspec = []
-        if self.context.custom_config:
+        if chroot:
+            chrootspec += ["-r", chroot]
+            self.context.chroot = chroot
+        elif self.context.custom_config:
             config_file = Path(self.context.workdir) / "custom.cfg"
             with config_file.open("w") as fd:
                 fd.write(f"include('{self.context.chroot}.cfg')\n")