deprecate show plots

docs/source/Support/bskReleaseNotes.rst

@@ -51,6 +51,7 @@ Version |release|
 - Fixed range of grammatical typos in the Basilisk documentation
 - Ensure the HTML documentation figures from the example scenario look more consistent
 - Avoid a memory leak when saving off figures in the CI Unit tests to build the online documentation
+- Deprecated the ``pytest`` optional flag ``show_plots``.
 
 
 Version 2.9.0 (Jan. 28 2026)

src/conftest.py

@@ -22,6 +22,7 @@
 import subprocess
 import sys
 import warnings
+from datetime import date
 
 import matplotlib as mpl
 import matplotlib.pyplot as plt
@@ -33,6 +34,14 @@
     category=DeprecationWarning,
 )
 
+SHOW_PLOTS_REMOVAL_DATE = date(2027, 2, 12)
+SHOW_PLOTS_DEPRECATION_MESSAGE = (
+    "The pytest option '--show_plots' is deprecated and will be removed after February 12, 2027."
+)
+SHOW_PLOTS_ELEVATED_MESSAGE = (
+    "The pytest option '--show_plots' has been deprecated for a year and will be removed shortly."
+)
+
 filename = inspect.getframeinfo(inspect.currentframe()).filename
 path = os.path.dirname(os.path.abspath(filename))
 print(path)
@@ -50,6 +59,25 @@ def pytest_addoption(parser):
                          help="whether or not to gen a pytest-html report. The report is saved in ./tests/report")
 
 
+def _show_plots_warning_details(today=None):
+    if today is None:
+        today = date.today()
+
+    if today > SHOW_PLOTS_REMOVAL_DATE:
+        return SHOW_PLOTS_ELEVATED_MESSAGE, "red"
+    return SHOW_PLOTS_DEPRECATION_MESSAGE, "yellow"
+
+
+def pytest_terminal_summary(terminalreporter, exitstatus, config):
+    if not config.getoption("--show_plots"):
+        return
+
+    warning_message, terminal_color = _show_plots_warning_details()
+    message = f"DEPRECATION WARNING: {warning_message}"
+    terminalreporter.write_sep("=", "SHOW_PLOTS DEPRECATION", **{terminal_color: True}, bold=True)
+    terminalreporter.write_line(message, **{terminal_color: True}, bold=True)
+
+
 @pytest.fixture(scope="module")
 def show_plots(request):
     return request.config.getoption("--show_plots")

src/tests/test_show_plots_cutoff_notice.py

@@ -0,0 +1,34 @@
+#
+#  ISC License
+#
+#  Copyright (c) 2026, Autonomous Vehicle Systems Lab, University of Colorado at Boulder
+#
+#  Permission to use, copy, modify, and/or distribute this software for any
+#  purpose with or without fee is hereby granted, provided that the above
+#  copyright notice and this permission notice appear in all copies.
+#
+#  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+#  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+#  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+#  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+#  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+#  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+#  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+#
+
+from datetime import date
+import warnings
+
+import conftest
+
+
+def test_show_plots_cutoff_notice():
+    """Emit a visible reminder after the cutoff date without failing tests."""
+    if date.today() <= conftest.SHOW_PLOTS_REMOVAL_DATE:
+        return
+
+    warnings.warn(
+        "The cutoff date for '--show_plots' has passed. Please remove the deprecated show_plots pytest option/fixture usage.",
+        UserWarning,
+        stacklevel=1,
+    )