add option to override verbosity on individual assert statements

pytest_robotframework/__init__.py

@@ -655,6 +655,7 @@ def __init__(
         log_pass: bool | None = None,
         description: str | None = None,
         fail_message: str | None = None,
+        verbosity: int | None = None,
     ) -> None:
         super().__init__()
         self.log_pass = log_pass
@@ -699,6 +700,27 @@ def __init__(
         `AssertionError` message if the assertion fails. equivalent to a normal `assert` statement's
         second argument"""
 
+        self.verbosiy = verbosity
+        """override the verbosity for this assert statement. by default, `assert` statements will
+        not show the full diff unless pytest is run with `-vv` (aka. `--verbosity=2`). the values
+        correspond to the following pytest arguments:
+
+        - `--verbosity=-1` (aka. `-q` / `--quiet`)
+        - `--verbosity=0` (the default verbosity)
+        - `--verbosity=1` (aka. `-v` / `--verbose`)
+        - `--verbosity=2` (aka. `-vv`)
+
+        values higher than 2 are allowed but have no effect in pytest itself, however some plugins
+        might make use of higher verbosity.
+
+        `None` means the verbosity will be unchanged from whatever level pytest was run with
+
+        example:
+        -------
+        due to [this issue](https://github.com/pytest-dev/pytest/issues/12009#issuecomment-2201710676),
+        this argument has no effect when run from CI.
+        """
+
     @override
     def __repr__(self) -> str:
         """make the custom fail message appear in the call to `AssertionError`"""

pytest_robotframework/_internal/pytest/plugin.py

@@ -37,7 +37,7 @@
 from robot.result.resultbuilder import ExecutionResult  # pyright:ignore[reportUnknownVariableType]
 from robot.run import RobotFramework, RobotSettings
 from robot.utils.error import ErrorDetails
-from typing_extensions import TYPE_CHECKING, Callable, Generator, Mapping, cast
+from typing_extensions import TYPE_CHECKING, Callable, Generator, Mapping, TypeVar, cast
 
 from pytest_robotframework import (
     AssertOptions,
@@ -87,14 +87,22 @@
     from types import TracebackType
 
     from _pytest.terminal import TerminalReporter
+    from basedtyping import Fn
     from pluggy import PluginManager
     from pytest import CallInfo, Item, Parser, Session
 
 
 _explanation_key = StashKey[str]()
 
 
-def _call_assertion_hook(
+def _assert_rewrite_context(fn: Fn) -> Fn:
+    """make the function available within the context of a rewritten assert statement"""
+    setattr(rewrite, fn.__name__, fn)
+    return fn
+
+
+@_assert_rewrite_context
+def _call_assertion_hook(  # pyright:ignore[reportUnusedFunction]
     expression: str,
     fail_message: object,
     line_number: int,
@@ -120,9 +128,29 @@ def _call_assertion_hook(
     )
 
 
-# we aren't patching an existing function here but instead adding a new one to the rewrite module,
-# since the rewritten assert statement needs to call it, and this is the easist way to do that
-rewrite._call_assertion_hook = _call_assertion_hook  # pyright:ignore[reportAttributeAccessIssue]
+_original_verbosity = StashKey[int]()
+
+
+@_assert_rewrite_context
+def _change_verbosity(fail_message: object):  # pyright:ignore[reportUnusedFunction]
+    if not isinstance(fail_message, AssertOptions) or fail_message.verbosiy is None:
+        return
+    item = current_item()
+    if not item:
+        return
+    item.stash[_original_verbosity] = item.config.get_verbosity(Config.VERBOSITY_ASSERTIONS)
+    _set_verbosity(item.config, fail_message.verbosiy)
+
+
+def _change_verbosity_back():
+    item = current_item()
+    if not item:
+        return
+    original_verbosity = item.stash.get(_original_verbosity, None)
+    if original_verbosity is None:
+        return
+    _set_verbosity(item.config, original_verbosity)
+    del item.stash[_original_verbosity]
 
 
 @patch_method(AssertionRewriter)
@@ -146,6 +174,9 @@ def visit_Assert(  # noqa: N802
     except StopIteration:
         raise InternalError("failed to find if statement for assertion rewriting") from None
     expression = _get_assertion_exprs(self.source)[assert_.lineno]
+    # call the verbosity override check right before the main test
+    result.insert(0, Expr(self.helper("_change_verbosity", assert_msg)))
+
     # rice the fail statements:
     raise_statement = cast(Raise, main_test.body.pop())
     if not raise_statement.exc:
@@ -184,7 +215,9 @@ def visit_Assert(  # noqa: N802
     return result
 
 
-HookWrapperResult = Generator[None, object, None]
+_T_default_object = TypeVar("_T_default_object", default=object)
+
+HookWrapperResult = Generator[None, _T_default_object, _T_default_object]
 
 
 def _xdist_temp_dir(session: Session) -> Path:
@@ -374,6 +407,10 @@ def _robot_run_tests(session: Session, xdist_item: Item | None = None):
     _ = _run_robot(session, robot_options)
 
 
+def _set_verbosity(config: Config, verbosity: int):
+    config._inicache["verbosity_assertions"] = verbosity  # pyright:ignore[reportPrivateUsage]
+
+
 def pytest_addhooks(pluginmanager: PluginManager):
     pluginmanager.add_hookspecs(hooks)
 
@@ -534,6 +571,8 @@ def pytest_robot_assertion(
         if not assertion_error and fail_message.log_pass is not None:
             show_in_log = fail_message.log_pass
         description = fail_message.description
+        if fail_message.verbosiy is not None:
+            _change_verbosity_back()
     else:
         description = None
     if show_in_log is None:

scripts/clear_pycache.py

@@ -1,9 +1,7 @@
 from __future__ import annotations
 
 from pathlib import Path
-
-for path in Path().rglob("*.py[co]"):
-    path.unlink()
+from shutil import rmtree
 
 for path in Path().rglob("__pycache__"):
-    path.rmdir()
+    rmtree(path)

tests/fixtures/test_python/test_assert_verbosity_overrides.py

@@ -0,0 +1,25 @@
+from __future__ import annotations
+
+from pytest import fixture
+
+from pytest_robotframework import AssertOptions
+
+# needed for fixtures
+# pylint:disable=redefined-outer-name
+
+
+@fixture
+def big_value():
+    return list(range(6))
+
+
+def test_default(big_value: list[int]):
+    assert big_value == []
+
+
+def test_verbose(big_value: list[int]):
+    assert big_value == [], AssertOptions(verbosity=2)
+
+
+def test_set_back_to_default(big_value: list[int]):
+    assert big_value == [1]

tests/test_python.py

@@ -959,3 +959,15 @@ def test_maxfail(pr: PytestRobotTester):
             "--maxfail doesn't work with xdist. https://github.com/pytest-dev/pytest-xdist/issues/868"
         )
     pr.run_and_assert_result("--maxfail=2", failed=2, skipped=1)
+
+
+def test_assert_verbosity_overrides(pr: PytestRobotTester, monkeypatch: MonkeyPatch):
+    # https://github.com/pytest-dev/pytest/issues/12009#issuecomment-2201710676
+    monkeypatch.delenv("CI", raising=False)
+    pr.run_and_assert_result("-o", "enable_assertion_pass_hook=true", failed=3)
+    xml = output_xml()
+    assert xml.xpath("//test[@name='test_default']//msg[contains(., 'Use -v to get more diff')]")
+    assert xml.xpath("//test[@name='test_verbose']//msg[contains(., 'Full diff:')]")
+    assert xml.xpath(
+        "//test[@name='test_set_back_to_default']//msg[contains(., 'Use -v to get more diff')]"
+    )