Add _ListPlot checking

Author: rocky

mathics/builtin/drawing/plot.py

@@ -286,11 +286,12 @@ class _ListPlot(Builtin, ABC):
     attributes = A_PROTECTED | A_READ_PROTECTED
 
     messages = {
+        "joind": "Value of option Joined -> `1` is not True or False.",
+        "lpn": "`1` is not a list of numbers or pairs of numbers.",
         "prng": (
             "Value of option PlotRange -> `1` is not All, Automatic or "
             "an appropriate list of range specifications."
         ),
-        "joind": "Value of option Joined -> `1` is not True or False.",
     }
 
     use_log_scale = False
@@ -309,6 +310,21 @@ def eval(self, points, evaluation: Evaluation, options: dict):
                 )
             )
 
+        points = points.evaluate(evaluation)
+        if not isinstance(points, ListExpression):
+            evaluation.message(class_name, "lpn", points)
+            return
+
+        if not all(
+            element.is_numeric(evaluation)
+            or isinstance(element, ListExpression)
+            or (1 <= len(element.elements) <= 2)
+            or (len(element.elements) == 1 and isinstance(element[0], ListExpression))
+            for element in points.elements
+        ):
+            evaluation.message(class_name, "lpn", points)
+            return
+
         # If "points" is a literal value with a Python representation,
         # it has a ".value" attribute with a non-None value. So here,
         # we don't have to eval_N().to_python().

test/builtin/drawing/test_plot.py

@@ -3,13 +3,40 @@
 Unit tests from mathics.builtin.drawing.plot
 """
 
-import sys
-import time
-from test.helper import check_evaluation, evaluate
+from test.helper import check_evaluation
 
 import pytest
 
 
+def test__listplot():
+    """tests for module builtin.drawing.plot._ListPlot"""
+    for str_expr, msgs, str_expected, fail_msg in (
+        (
+            "ListPlot[5]",
+            ("5 is not a list of numbers or pairs of numbers.",),
+            "ListPlot[5]",
+            "ListPlot with invalid list of point",
+        ),
+        (
+            "ListLinePlot[{{}, {{1., 1.}}, {{1., 2.}}, {}}]",
+            (
+                "{{}, {{1., 1.}}, {{1., 2.}}, {}} is not a list of numbers or pairs of numbers.",
+            ),
+            "ListLinePlot[{{}, {{1., 1.}}, {{1., 2.}}, {}}]",
+            "ListLinePlot with invalid list of point",
+        ),
+    ):
+        check_evaluation(
+            str_expr,
+            str_expected,
+            to_string_expr=True,
+            to_string_expected=True,
+            hold_expected=True,
+            failure_message=fail_msg,
+            expected_messages=msgs,
+        )
+
+
 @pytest.mark.parametrize(
     ("str_expr", "msgs", "str_expected", "fail_msg"),
     [
@@ -159,8 +186,8 @@
         ),
     ],
 )
-def test_private_doctests_plot(str_expr, msgs, str_expected, fail_msg):
-    """builtin.drawing.plot"""
+def test_plot(str_expr, msgs, str_expected, fail_msg):
+    """tests for module builtin.drawing.plot"""
     check_evaluation(
         str_expr,
         str_expected,