test(core): don't fetch DebugLinkState by default

In case the main workflow is restarting after a `DebugLinkDecision`,
the next `DebugLinkGetState` handling becomes inherently racy.

I would suggest making the state fetching explicit,
in order to avoid the "restart" race condition.

[no changelog]

Author: romanz

python/src/trezorlib/debuglink.py

@@ -65,7 +65,7 @@ def __call__(
             self,
             hold_ms: int | None = None,
             wait: bool | None = None,
-        ) -> "LayoutContent": ...
+        ) -> "LayoutContent | None": ...
 
     InputFlowType = Generator[None, messages.ButtonRequest, None]
 
@@ -417,10 +417,11 @@ def input_func(
         self: "DebugLink",
         hold_ms: int | None = None,
         wait: bool | None = None,
-    ) -> LayoutContent:
+        return_layout: bool = False,
+    ) -> LayoutContent | None:
         __tracebackhide__ = True  # for pytest # pylint: disable=W0612
         decision.hold_ms = hold_ms
-        return self._decision(decision, wait=wait)
+        return self._decision(decision, wait=wait, return_layout=return_layout)
 
     return input_func  # type: ignore [Parameter name mismatch]
 
@@ -635,9 +636,13 @@ def read_reset_word(self) -> str:
         return state.reset_word
 
     def _decision(
-        self, decision: messages.DebugLinkDecision, wait: bool | None = None
-    ) -> LayoutContent:
-        """Send a debuglink decision and returns the resulting layout.
+        self,
+        decision: messages.DebugLinkDecision,
+        *,
+        wait: bool | None = None,
+        return_layout: bool = False,
+    ) -> LayoutContent | None:
+        """Send a debuglink decision and optionally returns the resulting layout.
 
         If hold_ms is set, an additional 200ms is added to account for processing
         delays. (This is needed for hold-to-confirm to trigger reliably.)
@@ -657,8 +662,12 @@ def _decision(
         setting `wait=False` -- useful when, e.g., you are causing the next layout to be
         deliberately delayed.
         """
+        if wait is not None:
+            return_layout = True
+
         if not self.allow_interactions:
-            return self.wait_layout()
+            layout = self.wait_layout()
+            return layout if return_layout else None
 
         if decision.hold_ms is not None:
             decision.hold_ms += 200
@@ -671,7 +680,9 @@ def _decision(
             wait_type = DebugWaitType.IMMEDIATE
         else:
             wait_type = self.input_wait_type
-        return self._snapshot_core(wait_type)
+
+        if return_layout:
+            return self._snapshot_core(wait_type)
 
     press_yes = _make_input_func(button=messages.DebugButton.YES)
     """Confirm current layout. See `_decision` for more details."""
@@ -698,20 +709,30 @@ def _decision(
     )
     """Press right button. See `_decision` for more details."""
 
-    def input(self, word: str, wait: bool | None = None) -> LayoutContent:
+    def input(
+        self, word: str, *, wait: bool | None = None, return_layout: bool = False
+    ) -> LayoutContent | None:
         """Send text input to the device. See `_decision` for more details."""
-        return self._decision(messages.DebugLinkDecision(input=word), wait)
+        return self._decision(
+            messages.DebugLinkDecision(input=word),
+            wait=wait,
+            return_layout=return_layout,
+        )
 
     def click(
         self,
         click: Tuple[int, int],
+        *,
         hold_ms: int | None = None,
         wait: bool | None = None,
-    ) -> LayoutContent:
+        return_layout: bool = False,
+    ) -> LayoutContent | None:
         """Send a click to the device. See `_decision` for more details."""
         x, y = click
         return self._decision(
-            messages.DebugLinkDecision(x=x, y=y, hold_ms=hold_ms), wait
+            messages.DebugLinkDecision(x=x, y=y, hold_ms=hold_ms),
+            wait=wait,
+            return_layout=return_layout,
         )
 
     def _snapshot_core(

tests/click_tests/common.py

@@ -49,11 +49,11 @@ def get_char_category(char: str) -> PassphraseCategory:
 
 def go_next(debug: "DebugLink") -> LayoutContent:
     if debug.layout_type is LayoutType.Bolt:
-        return debug.click(buttons.OK)
+        return debug.click(buttons.OK, return_layout=True)
     elif debug.layout_type is LayoutType.Caesar:
-        return debug.press_right()
+        return debug.press_right(return_layout=True)
     elif debug.layout_type is LayoutType.Delizia:
-        return debug.swipe_up()
+        return debug.swipe_up(return_layout=True)
     else:
         raise RuntimeError("Unknown model")
 
@@ -64,19 +64,19 @@ def tap_to_confirm(debug: "DebugLink") -> LayoutContent:
     elif debug.layout_type is LayoutType.Caesar:
         return debug.read_layout()
     elif debug.layout_type is LayoutType.Delizia:
-        return debug.click(buttons.TAP_TO_CONFIRM)
+        return debug.click(buttons.TAP_TO_CONFIRM, return_layout=True)
     else:
         raise RuntimeError("Unknown model")
 
 
 def go_back(debug: "DebugLink", r_middle: bool = False) -> LayoutContent:
     if debug.layout_type in (LayoutType.Bolt, LayoutType.Delizia):
-        return debug.click(buttons.CANCEL)
+        return debug.click(buttons.CANCEL, return_layout=True)
     elif debug.layout_type is LayoutType.Caesar:
         if r_middle:
-            return debug.press_middle()
+            return debug.press_middle(return_layout=True)
         else:
-            return debug.press_left()
+            return debug.press_left(return_layout=True)
     else:
         raise RuntimeError("Unknown model")
 
@@ -108,10 +108,10 @@ def navigate_to_action_and_press(
 
     if steps < 0:
         for _ in range(-steps):
-            layout = debug.press_left()
+            debug.press_left()
     else:
         for _ in range(steps):
-            layout = debug.press_right()
+            debug.press_right()
 
     # Press or hold
     debug.press_middle(hold_ms=hold_ms)
@@ -125,11 +125,11 @@ def _carousel_steps(current_index: int, wanted_index: int, length: int) -> int:
 
 def unlock_gesture(debug: "DebugLink") -> LayoutContent:
     if debug.layout_type is LayoutType.Bolt:
-        return debug.click(buttons.OK)
+        return debug.click(buttons.OK, return_layout=True)
     elif debug.layout_type is LayoutType.Caesar:
-        return debug.press_right()
+        return debug.press_right(return_layout=True)
     elif debug.layout_type is LayoutType.Delizia:
-        return debug.click(buttons.TAP_TO_CONFIRM)
+        return debug.click(buttons.TAP_TO_CONFIRM, return_layout=True)
     else:
         raise RuntimeError("Unknown model")
 

tests/click_tests/recovery.py

@@ -23,7 +23,7 @@ def enter_word(
         if debug.layout_type is LayoutType.Delizia and not is_slip39 and len(word) > 4:
             # T3T1 (delizia) BIP39 keyboard allows to "confirm" only if the word is fully written, you need to click the word to auto-complete
             debug.click(buttons.CONFIRM_WORD)
-        return debug.click(buttons.CONFIRM_WORD)
+        return debug.click(buttons.CONFIRM_WORD, return_layout=True)
     elif debug.layout_type is LayoutType.Caesar:
         letter_index = 0
         layout = debug.read_layout()
@@ -32,16 +32,16 @@ def enter_word(
         while layout.find_values_by_key("letter_choices"):
             letter = word[letter_index]
             while not layout.get_middle_choice() == letter:
-                layout = debug.press_right()
+                layout = debug.press_right(return_layout=True)
 
-            layout = debug.press_middle()
+            layout = debug.press_middle(return_layout=True)
             letter_index += 1
 
         # Word choices
         while not layout.get_middle_choice() == word:
-            layout = debug.press_right()
+            layout = debug.press_right(return_layout=True)
 
-        return debug.press_middle()
+        return debug.press_middle(return_layout=True)
     else:
         raise ValueError("Unknown model")
 
@@ -78,15 +78,15 @@ def select_bolt() -> "LayoutContent":
         coords = coords_map.get(num_of_words)
         if coords is None:
             raise ValueError("Invalid num_of_words")
-        return debug.click(coords)
+        return debug.click(coords, return_layout=True)
 
     def select_caesar() -> "LayoutContent":
         # navigate to the number and confirm it
         word_options = (20, 33) if unlock_repeated_backup else (12, 18, 20, 24, 33)
         index = word_options.index(num_of_words)
         for _ in range(index):
             debug.press_right()
-        return debug.press_middle()
+        return debug.press_middle(return_layout=True)
 
     def select_delizia() -> "LayoutContent":
         # click the button from ValuePad
@@ -103,17 +103,17 @@ def select_delizia() -> "LayoutContent":
         coords = coords_map.get(num_of_words)
         if coords is None:
             raise ValueError("Invalid num_of_words")
-        return debug.click(coords)
+        return debug.click(coords, return_layout=True)
 
     if debug.layout_type is LayoutType.Bolt:
         assert debug.read_layout().text_content() == TR.recovery__num_of_words
-        layout = select_bolt()
+        layout = select_bolt(return_layout=True)
     elif debug.layout_type is LayoutType.Caesar:
-        layout = debug.press_right()
+        layout = debug.press_right(return_layout=True)
         assert layout.title() == TR.word_count__title
-        layout = select_caesar()
+        layout = select_caesar(return_layout=True)
     elif debug.layout_type is LayoutType.Delizia:
-        layout = select_delizia()
+        layout = select_delizia(return_layout=True)
     else:
         raise ValueError("Unknown model")
 
@@ -150,12 +150,12 @@ def enter_share(
         assert TR.translate(before_title) in debug.read_layout().title()
         layout = debug.read_layout()
         for _ in range(layout.page_count()):
-            layout = debug.press_right()
+            layout = debug.press_right(return_layout=True)
     elif debug.layout_type is LayoutType.Delizia:
-        layout = debug.swipe_up()
+        layout = debug.swipe_up(return_layout=True)
     else:
         assert TR.translate(before_title) in debug.read_layout().title()
-        layout = debug.click(buttons.OK)
+        layout = debug.click(buttons.OK, return_layout=True)
 
     assert "MnemonicKeyboard" in layout.all_components()
 
@@ -236,13 +236,13 @@ def enter_seed_previous_correct(
                 layout = debug.read_layout()
 
                 while layout.get_middle_choice() not in DELETE_BTNS:
-                    layout = debug.press_right()
-                layout = debug.press_middle()
+                    layout = debug.press_right(return_layout=True)
+                layout = debug.press_middle(return_layout=True)
 
                 for _ in range(len(bad_word)):
                     while layout.get_middle_choice() not in DELETE_BTNS:
-                        layout = debug.press_left()
-                    layout = debug.press_middle()
+                        layout = debug.press_left(return_layout=True)
+                    layout = debug.press_middle(return_layout=True)
             elif debug.layout_type is LayoutType.Delizia:
                 debug.click(buttons.RECOVERY_DELETE)  # Top-left
                 for _ in range(len(bad_word)):
@@ -278,7 +278,7 @@ def prepare_enter_seed(
     elif debug.layout_type is LayoutType.Caesar:
         debug.press_right()
         debug.press_right()
-        layout = debug.press_right()
+        layout = debug.press_right(return_layout=True)
         assert "MnemonicKeyboard" in layout.all_components()
 
 

tests/click_tests/reset.py

@@ -79,7 +79,7 @@ def set_selection(debug: "DebugLink", button: tuple[int, int], diff: int) -> Non
             in TR.reset__title_number_of_shares + TR.words__title_threshold
         ):
             # Special info screens
-            layout = debug.press_right()
+            layout = debug.press_right(return_layout=True)
         assert "NumberInput" in layout.all_components()
         if button == buttons.reset_minus(debug.model.internal_name):
             for _ in range(diff):
@@ -102,7 +102,7 @@ def read_words(debug: "DebugLink", do_htc: bool = True) -> list[str]:
     layout = debug.read_layout()
     for _ in range(layout.page_count() - 1):
         words.extend(layout.seed_words())
-        layout = debug.swipe_up()
+        layout = debug.swipe_up(return_layout=True)
         assert layout is not None
     if debug.layout_type in (LayoutType.Bolt, LayoutType.Delizia):
         words.extend(layout.seed_words())
@@ -130,7 +130,7 @@ def confirm_words(debug: "DebugLink", words: list[str]) -> None:
     if debug.layout_type is LayoutType.Delizia:
         debug.swipe_up()
 
-    layout = debug.read_layout()
+    layout = debug.read_layout(return_layout=True)
     if debug.layout_type is LayoutType.Bolt:
         assert TR.regexp("reset__select_word_x_of_y_template").match(
             layout.text_content()
@@ -147,7 +147,9 @@ def confirm_words(debug: "DebugLink", words: list[str]) -> None:
             ]
             wanted_word = words[word_pos - 1].lower()
             button_pos = btn_texts.index(wanted_word)
-            layout = debug.click(buttons.RESET_WORD_CHECK[button_pos])
+            layout = debug.click(
+                buttons.RESET_WORD_CHECK[button_pos], return_layout=True
+            )
     elif debug.layout_type is LayoutType.Delizia:
         assert TR.regexp("reset__select_word_x_of_y_template").match(layout.subtitle())
         for _ in range(3):
@@ -162,10 +164,10 @@ def confirm_words(debug: "DebugLink", words: list[str]) -> None:
             ]
             wanted_word = words[word_pos - 1].lower()
             button_pos = btn_texts.index(wanted_word)
-            layout = debug.click(buttons.VERTICAL_MENU[button_pos])
+            layout = debug.click(buttons.VERTICAL_MENU[button_pos], return_layout=True)
     elif debug.layout_type is LayoutType.Caesar:
         assert TR.reset__select_correct_word in layout.text_content()
-        layout = debug.press_right()
+        layout = debug.press_right(return_layout=True)
         for _ in range(3):
             # "SELECT 2ND WORD"
             #         ^
@@ -176,9 +178,9 @@ def confirm_words(debug: "DebugLink", words: list[str]) -> None:
             wanted_word = words[word_pos - 1].lower()
 
             while not layout.get_middle_choice() == wanted_word:
-                layout = debug.press_right()
+                layout = debug.press_right(return_layout=True)
 
-            layout = debug.press_middle()
+            layout = debug.press_middle(return_layout=True)
 
 
 def validate_mnemonics(mnemonics: list[str], expected_ems: bytes) -> None: