twister: refactor DUT class to dataclass for serialization support

Convert the DUT class from a traditional class to a dataclass to enable
proper serialization and support for future multi-device testing with
pytest-harness.

Key changes:
- Migrated DUT class to use `dataclass` decorator with proper type hints
- Renamed `baud` property to `serial_baud` for consistency
- Updated hardware map schema to support both `baud` (legacy) and
`serial_baud` fields for backward compatibility
- Updated tests

Signed-off-by: Grzegorz Chwierut <grzegorz.chwierut@nordicsemi.no>

scripts/pylib/twister/twisterlib/handlers.py

@@ -765,7 +765,7 @@ class DeviceHandler(Handler):
             ser_pty_master, slave = pty.openpty()
             serial_device = os.ttyname(slave)
 
-        logger.debug(f"Using serial device {serial_device} @ {hardware.baud} baud")
+        logger.debug(f"Using serial device {serial_device} @ {hardware.serial_baud} baud")
 
         command = self._create_command(runner, hardware)
 
@@ -787,7 +787,7 @@ class DeviceHandler(Handler):
             ser = self._create_serial_connection(
                 hardware,
                 serial_port,
-                hardware.baud,
+                hardware.serial_baud,
                 flash_timeout,
                 serial_pty,
                 ser_pty_process
@@ -848,7 +848,7 @@ class DeviceHandler(Handler):
             try:
                 if serial_pty:
                     ser_pty_process = self._start_serial_pty(serial_pty, ser_pty_master)
-                logger.debug(f"Attach serial device {serial_device} @ {hardware.baud} baud")
+                logger.debug(f"Attach serial device {serial_device} @ {hardware.serial_baud} baud")
                 ser.port = serial_device
 
                 # Apply ESP32-specific RTS/DTR reset logic

scripts/pylib/twister/twisterlib/hardwaremap.py

@@ -3,13 +3,16 @@
 #
 # Copyright (c) 2022 Intel Corporation
 # SPDX-License-Identifier: Apache-2.0
+from __future__ import annotations
 
 import logging
 import os
 import platform
 import re
+from dataclasses import asdict, dataclass, field
 from multiprocessing import Lock, Value
 from pathlib import Path
+from typing import Any
 
 import scl
 import yaml
@@ -32,50 +35,39 @@ except ImportError:
 logger = logging.getLogger('twister')
 
 
+@dataclass
 class DUT:
-    def __init__(self,
-                 id=None,
-                 serial=None,
-                 serial_baud=None,
-                 platform=None,
-                 product=None,
-                 serial_pty=None,
-                 connected=False,
-                 runner_params=None,
-                 pre_script=None,
-                 post_script=None,
-                 post_flash_script=None,
-                 script_param=None,
-                 runner=None,
-                 flash_timeout=60,
-                 flash_with_test=False,
-                 flash_before=False):
+    """Device Under Test configuration."""
+    id: str | None = None
+    serial: str | None = None
+    serial_baud: int = 115200
+    platform: str | None = None
+    product: str | None = None
+    serial_pty: str | None = None
+    connected: bool = False
+    runner_params: str | None = None
+    pre_script: str | None = None
+    post_script: str | None = None
+    post_flash_script: str | None = None
+    script_param: str | None = None
+    runner: str | None = None
+    flash_timeout: int = 60
+    flash_with_test: bool = False
+    flash_before: bool = False
+    fixtures: list[str] = field(default_factory=list)
+    probe_id: str | None = None
+    notes: str | None = None
+    match: bool = False
 
-        self.serial = serial
-        self.baud = serial_baud or 115200
-        self.platform = platform
-        self.serial_pty = serial_pty
+    def __post_init__(self):
+        """Initialize non-serializable objects after dataclass initialization."""
+        # These are not dataclass fields, so they won't be serialized by asdict()
         self._counter = Value("i", 0)
         self._available = Value("i", 1)
         self._failures = Value("i", 0)
-        self.connected = connected
-        self.pre_script = pre_script
-        self.id = id
-        self.product = product
-        self.runner = runner
-        self.runner_params = runner_params
-        self.flash_before = flash_before
-        self.fixtures = []
-        self.post_flash_script = post_flash_script
-        self.post_script = post_script
-        self.pre_script = pre_script
-        self.script_param = script_param
-        self.probe_id = None
-        self.notes = None
         self.lock = Lock()
-        self.match = False
-        self.flash_timeout = flash_timeout
-        self.flash_with_test = flash_with_test
+        # Ensure serial_baud has a default value
+        self.serial_baud = self.serial_baud or 115200
 
     @property
     def available(self):
@@ -115,19 +107,16 @@ class DUT:
         with self._failures.get_lock():
             self._failures.value += value
 
-    def to_dict(self):
-        d = {}
-        exclude = ['_available', '_counter', '_failures', 'match']
-        v = vars(self)
-        for k in v:
-            if k not in exclude and v[k]:
-                d[k] = v[k]
-        return d
-
+    def to_dict(self) -> dict[str, Any]:
+        """Convert DUT dataclass to dictionary for YAML serialization."""
+        result = asdict(self)
+        # Remove None and False values and empty lists to keep YAML clean
+        return {k: v for k, v in result.items() if v}
 
     def __repr__(self):
         return f"<{self.platform} ({self.product}) on {self.serial}>"
 
+
 class HardwareMap:
     schema_path = os.path.join(ZEPHYR_BASE, "scripts", "schemas", "twister", "hwmap-schema.yaml")
 
@@ -170,7 +159,7 @@ class HardwareMap:
     }
 
     def __init__(self, env=None):
-        self.detected = []
+        self.detected: list[DUT] = []
         self.duts: list[DUT] = []
         self.options = env.options
 
@@ -295,7 +284,7 @@ class HardwareMap:
             runner = dut.get('runner')
             runner_params = dut.get('runner_params')
             serial = dut.get('serial')
-            baud = dut.get('baud', None)
+            serial_baud = dut.get('serial_baud', None) or dut.get('baud', None)
             product = dut.get('product')
             fixtures = dut.get('fixtures', [])
             connected = dut.get('connected') and ((serial or serial_pty) is not None)
@@ -309,7 +298,7 @@ class HardwareMap:
                               id=id,
                               serial_pty=serial_pty,
                               serial=serial,
-                              serial_baud=baud,
+                              serial_baud=serial_baud,
                               connected=connected,
                               pre_script=pre_script,
                               flash_before=flash_before,

scripts/pylib/twister/twisterlib/harness.py

@@ -463,7 +463,7 @@ class Pytest(Harness):
         else:
             command.extend([
                 f'--device-serial={hardware.serial}',
-                f'--device-serial-baud={hardware.baud}'
+                f'--device-serial-baud={hardware.serial_baud}'
             ])
             for extra_serial in handler.get_more_serials_from_device(hardware):
                 command.append(f'--device-serial={extra_serial}')

scripts/schemas/twister/hwmap-schema.yaml

@@ -41,6 +41,9 @@ sequence:
       "baud":
         type: int
         required: false
+      "serial_baud":
+        type: int
+        required: false
       "post_script":
         type: str
         required: false

scripts/tests/twister/test_hardwaremap.py

@@ -37,7 +37,7 @@ def mocked_hm():
 TESTDATA_1 = [
     (
         {},
-        {'baud': 115200, 'lock': mock.ANY, 'flash_timeout': 60},
+        {'serial_baud': 115200, 'flash_timeout': 60},
         '<None (None) on None>'
     ),
     (
@@ -63,10 +63,9 @@ TESTDATA_1 = [
                 }
         },
         {
-            'lock': mock.ANY,
             'id': 'dummy id',
             'serial': 'dummy serial',
-            'baud': 4400,
+            'serial_baud': 4400,
             'platform': 'dummy platform',
             'product': 'dummy product',
             'serial_pty': 'dummy serial pty',
@@ -269,7 +268,7 @@ def test_hardwaremap_load():
   runner: r0
   flash_with_test: True
   flash_timeout: 15
-  baud: 14400
+  serial_baud: 14400
   fixtures:
   - dummy fixture 1
   - dummy fixture 2
@@ -310,7 +309,7 @@ def test_hardwaremap_load():
             'runner': 'r0',
             'flash_timeout': 15,
             'flash_with_test': True,
-            'baud': 14400,
+            'serial_baud': 14400,
             'fixtures': ['dummy fixture 1', 'dummy fixture 2'],
             'connected': True,
             'serial': 'dummy',
@@ -322,7 +321,7 @@ def test_hardwaremap_load():
             'runner': 'r1',
             'flash_timeout': 30,
             'flash_with_test': False,
-            'baud': 115200,
+            'serial_baud': 115200,
             'fixtures': [],
             'connected': True,
             'serial': None,
@@ -503,50 +502,45 @@ TESTDATA_5 = [
         '',
         [{
             'serial': 's1',
-            'baud': 115200,
+            'serial_baud': 115200,
             'platform': 'p1',
             'connected': True,
             'id': 1,
             'product': 'pr1',
-            'lock': mock.ANY,
             'flash_timeout': 60
         },
         {
             'serial': 's2',
-            'baud': 115200,
+            'serial_baud': 115200,
             'platform': 'p2',
             'id': 2,
             'product': 'pr2',
-            'lock': mock.ANY,
             'flash_timeout': 60
         },
         {
             'serial': 's3',
-            'baud': 115200,
+            'serial_baud': 115200,
             'platform': 'p3',
             'connected': True,
             'id': 3,
             'product': 'pr3',
-            'lock': mock.ANY,
             'flash_timeout': 60
         },
         {
             'serial': 's4',
-            'baud': 115200,
+            'serial_baud': 115200,
             'platform': 'p4',
             'id': 4,
             'product': 'pr4',
-            'lock': mock.ANY,
             'flash_timeout': 60
         },
         {
             'serial': 's5',
-            'baud': 115200,
+            'serial_baud': 115200,
             'platform': 'p5',
             'connected': True,
             'id': 5,
             'product': 'pr5',
-            'lock': mock.ANY,
             'flash_timeout': 60
         }]
     ),
@@ -603,41 +597,37 @@ TESTDATA_5 = [
         },
         {
             'serial': 's1',
-            'baud': 115200,
+            'serial_baud': 115200,
             'platform': 'p1',
             'connected': True,
             'id': 1,
             'product': 'pr1',
-            'lock': mock.ANY,
             'flash_timeout': 60
         },
         {
             'serial': 's2',
-            'baud': 115200,
+            'serial_baud': 115200,
             'platform': 'p2',
             'id': 2,
             'product': 'pr2',
-            'lock': mock.ANY,
             'flash_timeout': 60
         },
         {
             'serial': 's3',
-            'baud': 115200,
+            'serial_baud': 115200,
             'platform': 'p3',
             'connected': True,
             'id': 3,
             'product': 'pr3',
-            'lock': mock.ANY,
             'flash_timeout': 60
         },
         {
             'serial': 's5',
-            'baud': 115200,
+            'serial_baud': 115200,
             'platform': 'p5',
             'connected': True,
             'id': 5,
             'product': 'pr5',
-            'lock': mock.ANY,
             'flash_timeout': 60
         }]
     ),

scripts/tests/twister/test_harness.py

@@ -552,7 +552,7 @@ def test_pytest__generate_parameters_for_hardware(tmp_path, pty_value, hardware_
     hardware = mock.Mock()
     hardware.serial_pty = pty_value
     hardware.serial = "serial"
-    hardware.baud = 115200
+    hardware.serial_baud = 115200
     hardware.runner = "runner"
     hardware.runner_params = ["--runner-param1", "runner-param2"]
     hardware.fixtures = ["fixture1:option1", "fixture2"]

scripts/tests/twister_blackbox/test_hardwaremap.py

@@ -112,7 +112,7 @@ class TestHardwaremap:
     def test_generate(self, capfd, out_path, manufacturer, product, serial, runner):
         file_name = "test-map.yaml"
         path = os.path.join(ZEPHYR_BASE, file_name)
-        args = ['--outdir', out_path, '--generate-hardware-map', file_name]
+        args = ['--outdir', out_path, '--generate-hardware-map', path]
 
         if os.path.exists(path):
             os.remove(path)
@@ -164,7 +164,7 @@ class TestHardwaremap:
     def test_few_generate(self, capfd, out_path, manufacturer, product, serial, runner):
         file_name = "test-map.yaml"
         path = os.path.join(ZEPHYR_BASE, file_name)
-        args = ['--outdir', out_path, '--generate-hardware-map', file_name]
+        args = ['--outdir', out_path, '--generate-hardware-map', path]
 
         if os.path.exists(path):
             os.remove(path)
@@ -245,7 +245,7 @@ class TestHardwaremap:
     def test_texas_exeption(self, capfd, out_path, manufacturer, product, serial, location):
         file_name = "test-map.yaml"
         path = os.path.join(ZEPHYR_BASE, file_name)
-        args = ['--outdir', out_path, '--generate-hardware-map', file_name]
+        args = ['--outdir', out_path, '--generate-hardware-map', path]
 
         if os.path.exists(path):
             os.remove(path)