twister: apply_filter: discards is not part of TestPlan

Use class member instead of local variable of discards.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>

scripts/pylib/twister/twisterlib.py

@@ -3763,14 +3763,14 @@ class TestPlan(DisablePyTestCollectionMixin):
             for case in instance.testcases:
                 case = instance.status
 
-        self.filtered_platforms = set(p.platform.name for p in self.instances.values()
-                                      if p.status != "skipped" )
-
-        # Remove from discards configurations that must not be discarded (e.g. integration_platforms when --integration was used)
+        # Remove from discards configurations that must not be discarded
+        # (e.g. integration_platforms when --integration was used)
         for instance in remove_from_discards:
             del self.discards[instance]
 
-        return discards
+        self.filtered_platforms = set(p.platform.name for p in self.instances.values()
+                                      if p.status != "skipped" )
+
 
     def add_instances(self, instance_list):
         for instance in instance_list:

scripts/tests/twister/test_testplan_class.py

@@ -106,8 +106,8 @@ def test_apply_filters_part1(class_testplan, all_testsuites_dict, platforms_list
             appropriate values according to the filters
     """
     if tc_attribute is None and plat_attribute is None:
-        discards = class_testplan.apply_filters()
-        assert not discards
+        class_testplan.apply_filters()
+        assert not class_testplan.discards
 
     class_testplan.platforms = platforms_list
     class_testplan.platform_names = [p.name for p in platforms_list]
@@ -149,19 +149,19 @@ def test_apply_filters_part1(class_testplan, all_testsuites_dict, platforms_list
     if tc_attribute == "build_on_all":
         for _, testcase in class_testplan.testsuites.items():
             testcase.build_on_all = tc_value
-        discards = class_testplan.apply_filters(exclude_platform=['demo_board_1'])
+        class_testplan.apply_filters(exclude_platform=['demo_board_1'])
     elif plat_attribute == "supported_toolchains":
-        discards = class_testplan.apply_filters(force_toolchain=False,
+        class_testplan.apply_filters(force_toolchain=False,
                                                  exclude_platform=['demo_board_1'],
                                                  platform=['demo_board_2'])
     elif tc_attribute is None and plat_attribute is None:
-        discards = class_testplan.apply_filters()
+        class_testplan.apply_filters()
     else:
-        discards = class_testplan.apply_filters(exclude_platform=['demo_board_1'],
+        class_testplan.apply_filters(exclude_platform=['demo_board_1'],
                                                  platform=['demo_board_2'])
 
     for x in [expected_discards]:
-        assert x in discards.values()
+        assert x in class_testplan.discards.values()
 
 TESTDATA_PART2 = [
     ("runnable", "True", "Not runnable on device"),
@@ -192,9 +192,9 @@ def test_apply_filters_part2(class_testplan, all_testsuites_dict,
             'demo_board_2'
             ]
         }
-    discards = class_testplan.apply_filters(**kwargs)
-    assert discards
-    for d in discards.values():
+    class_testplan.apply_filters(**kwargs)
+    assert class_testplan.discards
+    for d in class_testplan.discards.values():
         assert d == expected_discards
 
 
@@ -221,9 +221,9 @@ def test_apply_filters_part3(class_testplan, all_testsuites_dict, platforms_list
     for _, testcase in class_testplan.testsuites.items():
         testcase.min_ram = tc_min_ram
         testcase.min_flash = tc_min_flash
-    discards = class_testplan.apply_filters(exclude_platform=['demo_board_1'],
+    class_testplan.apply_filters(exclude_platform=['demo_board_1'],
                                              platform=['demo_board_2'])
-    assert not discards
+    assert not class_testplan.discards
 
 def test_add_instances(test_data, class_testplan, all_testsuites_dict, platforms_list):
     """ Testing add_instances() function of TestPlan class in Twister

scripts/twister

@@ -1079,8 +1079,6 @@ def main():
                     print("%s%s" % (pre, node.name))
             return
 
-    discards = []
-
     if options.report_suffix:
         last_run = os.path.join(options.outdir, "twister_{}.json".format(options.report_suffix))
     else:
@@ -1115,7 +1113,7 @@ def main():
                              filter_platform=connected_list)
         tplan.selected_platforms = set(p.platform.name for p in tplan.instances.values())
     else:
-        discards = tplan.apply_filters(
+        tplan.apply_filters(
             enable_slow=options.enable_slow,
             platform=options.platform,
             exclude_platform=options.exclude_platform,
@@ -1148,13 +1146,13 @@ def main():
             print(f"Tests found: {count}")
         return
 
-    if VERBOSE > 1 and discards:
+    if VERBOSE > 1 and tplan.discards:
         # if we are using command line platform filter, no need to list every
         # other platform as excluded, we know that already.
         # Show only the discards that apply to the selected platforms on the
         # command line
 
-        for i, reason in discards.items():
+        for i, reason in tplan.discards.items():
             if options.platform and i.platform.name not in options.platform:
                 continue
             logger.debug(