tools.calculation: replace deprecated ast.Num with ast.Constant

[dgw]

ast.Num and friends have been deprecated since Python 3.8, but only started to generate warnings in Python 3.12 prereleases.

Feels like stdlib made a bad trade here, simplifying Python internals in exchange for making users write uglier, more complicated type checks such as this. But it's been so long, it's not as if they'll un-deprecate the older, more-convenient-for-the-user classes.

Compatibility

I was under the impression that ast.Constant would work as far back as Python 3.6, but apparently not. This change has to wait until we're ready to drop Python 3.7.

Checklist

• I have read CONTRIBUTING.md
• I can and do license this contribution under the EFLv2
• No issues are reported by make qa (runs make quality and make test)
• I have tested the functionality of the things this change touches

[dgw]

Well, there are no direct tests of this module… Even though CI passes, I don't really trust it that much.

I've started work on a test/tools/test_tools_calculation.py suite. But that's out of scope of this PR, and doesn't need to be done for 8.0 specifically, so I will mark this as ready for review and just show up with the test suite later when I'm done with it.

[SnoopJ]

LGTM. Not having tests is I think no great sin, since that's not a change to the state of the module prior to this PR. Nice to have it covered, but doesn't need to be another thing weighing down 8.0.

Ship it!

[Exirel]

One more thing to add to the list of stuff to add tests for I guess.

At some point, we might also consider deprecating this tool, and extract the plugin that needs that code.

[SnoopJ]

Had a go at writing a basic set of tests for tools.calculation if you'd like to add them to this PR. Also wrote some up for the calc, dice plugins, I've opened #2503 for those (but can add the test listed here to that one if you'd prefer, let me know)

click for diff

diff --git a/test/tools/test_tools_calculation.py b/test/tools/test_tools_calculation.py
new file mode 100644
index 00000000..9f858285
--- /dev/null
+++ b/test/tools/test_tools_calculation.py
@@ -0,0 +1,35 @@
+from __future__ import annotations
+
+import ast
+import operator
+
+import pytest
+
+from sopel.tools.calculation import EquationEvaluator, ExpressionEvaluator
+
+
+def test_expression_eval():
+    OPS = {
+        ast.Add: operator.add,
+        ast.Sub: operator.sub,
+    }
+    evaluator = ExpressionEvaluator(bin_ops=OPS)
+
+    assert evaluator("1 + 1") == 2
+    assert evaluator("43 - 1") == 42
+    assert evaluator("1 + 1 - 2") == 0
+
+    with pytest.raises(ExpressionEvaluator.Error):
+        evaluator("2 * 2")
+
+
+def test_equation_eval():
+    evaluator = EquationEvaluator()
+
+    assert evaluator("1 + 1") == 2
+    assert evaluator("43 - 1") == 42
+    assert evaluator("(((1 + 1 + 2) * 3 / 5) ** 8 - 13) // 21 % 35") == 16.0
+    assert evaluator("-42") == -42
+    assert evaluator("-(-42)") == 42
+    assert evaluator("+42") == 42
+    assert evaluator("3 ^ 2") == 9

[dgw]

Had a go at writing a basic set of tests for tools.calculation if you'd like to add them to this PR.

I've adopted them into my WIP branch for adding tests to this module. This PR is already double-approved, and I'd rather not kibosh that status. 😁 But I appreciate that your quick patch gets the module to 81% coverage already! I'll have a look at the helpers and error cases at my leisure, probably for submission to the 8.1 cycle (coincidence?).