scripts: tests: Blackbox test expansion - platform

Adds tests related to the Twister's platform selection:
* -A, --board-root
* -K, --force-platform
* -p, --platform

Signed-off-by: Lukasz Mrugala <lukaszx.mrugala@intel.com>

scripts/tests/twister_blackbox/test_data/boards/others/dummy_board/board.yml

@@ -0,0 +1,5 @@
+board:
+  name: dummy
+  vendor: others
+  socs:
+  - name: dummy_soc

scripts/tests/twister_blackbox/test_data/boards/others/dummy_board/dummy.yaml

@@ -0,0 +1,4 @@
+name: dummy_board
+vendor: others
+arch: unit
+identifier: dummy_board/dummy_soc

scripts/tests/twister_blackbox/test_platform.py

@@ -0,0 +1,109 @@
+#!/usr/bin/env python3
+# Copyright (c) 2024 Intel Corporation
+#
+# SPDX-License-Identifier: Apache-2.0
+"""
+Blackbox tests for twister's command line functions related to Zephyr platforms.
+"""
+
+import importlib
+import re
+import mock
+import os
+import pytest
+import sys
+import json
+
+from conftest import ZEPHYR_BASE, TEST_DATA, testsuite_filename_mock
+from twisterlib.testplan import TestPlan
+
+
+class TestPlatform:
+    @classmethod
+    def setup_class(cls):
+        apath = os.path.join(ZEPHYR_BASE, 'scripts', 'twister')
+        cls.loader = importlib.machinery.SourceFileLoader('__main__', apath)
+        cls.spec = importlib.util.spec_from_loader(cls.loader.name, cls.loader)
+        cls.twister_module = importlib.util.module_from_spec(cls.spec)
+
+    @classmethod
+    def teardown_class(cls):
+        pass
+
+    @pytest.mark.parametrize(
+        'board_root, expected_returncode',
+        [(True, '0'), (False, '2')],
+        ids=['dummy in additional board root', 'no additional board root, crash']
+    )
+    @mock.patch.object(TestPlan, 'TESTSUITE_FILENAME', testsuite_filename_mock)
+    def test_board_root(self, out_path, board_root, expected_returncode):
+        test_platforms = ['qemu_x86', 'dummy_board/dummy_soc']
+        board_root_path = os.path.join(TEST_DATA, 'boards')
+        path = os.path.join(TEST_DATA, 'tests', 'dummy')
+        args = ['-i', '--outdir', out_path, '-T', path, '-y'] + \
+               (['--board-root', board_root_path] if board_root else []) + \
+               [val for pair in zip(
+                   ['-p'] * len(test_platforms), test_platforms
+               ) for val in pair]
+
+        with mock.patch.object(sys, 'argv', [sys.argv[0]] + args), \
+                pytest.raises(SystemExit) as sys_exit:
+            self.loader.exec_module(self.twister_module)
+
+        # Checking twister.log increases coupling,
+        # but we need to differentiate crashes.
+        with open(os.path.join(out_path, 'twister.log')) as f:
+            log = f.read()
+            error_regex = r'ERROR.*platform_filter\s+-\s+unrecognized\s+platform\s+-\s+dummy_board/dummy_soc$'
+            board_error = re.search(error_regex, log)
+            assert board_error if not board_root else not board_error
+
+        assert str(sys_exit.value) == expected_returncode
+
+    @mock.patch.object(TestPlan, 'TESTSUITE_FILENAME', testsuite_filename_mock)
+    def test_force_platform(self, out_path):
+        test_platforms = ['qemu_x86', 'frdm_k64f']
+        path = os.path.join(TEST_DATA, 'tests', 'dummy')
+        args = ['-i', '--outdir', out_path, '-T', path, '-y'] + \
+               ['--force-platform'] + \
+               [val for pair in zip(
+                   ['-p'] * len(test_platforms), test_platforms
+               ) for val in pair]
+
+        with mock.patch.object(sys, 'argv', [sys.argv[0]] + args), \
+                pytest.raises(SystemExit) as sys_exit:
+            self.loader.exec_module(self.twister_module)
+
+        with open(os.path.join(out_path, 'testplan.json')) as f:
+            j = json.load(f)
+        filtered_j = [
+            (ts['platform'], ts['name'], tc['identifier']) \
+               for ts in j['testsuites'] \
+               for tc in ts['testcases'] if 'reason' not in tc
+        ]
+
+        assert str(sys_exit.value) == '0'
+
+        assert len(filtered_j) == 12
+
+    @mock.patch.object(TestPlan, 'TESTSUITE_FILENAME', testsuite_filename_mock)
+    def test_platform(self, out_path):
+        path = os.path.join(TEST_DATA, 'tests', 'dummy')
+        args = ['-i', '--outdir', out_path, '-T', path, '-y'] + \
+               ['--platform', 'qemu_x86']
+
+        with mock.patch.object(sys, 'argv', [sys.argv[0]] + args), \
+                pytest.raises(SystemExit) as sys_exit:
+            self.loader.exec_module(self.twister_module)
+
+        with open(os.path.join(out_path, 'testplan.json')) as f:
+            j = json.load(f)
+        filtered_j = [
+            (ts['platform'], ts['name'], tc['identifier']) \
+               for ts in j['testsuites'] \
+               for tc in ts['testcases'] if 'reason' not in tc
+        ]
+
+        assert str(sys_exit.value) == '0'
+
+        assert all([platform == 'qemu_x86' for platform, _, _ in filtered_j])

subsys/testsuite/soc/unit/dummy_board/soc.yml

@@ -0,0 +1,2 @@
+socs:
+- name: dummy_soc