From ced7fbd7c336424612d821901546a5c8183ae778 Mon Sep 17 00:00:00 2001
From: wagesj45 <jordan@jordanwages.com>
Date: Wed, 20 Aug 2025 05:53:37 -0500
Subject: [PATCH] tests(stdlib): add tests for abs, sign, min, max, constants

---
 src/tests/StdlibFunctionsTests.cs | 72 ++++++++++++++++++++++++++++++-
 1 file changed, 71 insertions(+), 1 deletion(-)

diff --git a/src/tests/StdlibFunctionsTests.cs b/src/tests/StdlibFunctionsTests.cs
index 1121ba2..2bb097e 100644
--- a/src/tests/StdlibFunctionsTests.cs
+++ b/src/tests/StdlibFunctionsTests.cs
@@ -20,5 +20,75 @@ public class StdlibFunctionsTests
         Constants.Initialize(_interp);
         Functions.Initialize(_interp); ;
     }
-}
 
+    private static void AssertSuccess(decimal result, decimal expected, InputInterpreter interp)
+    {
+        Assert.That(result, Is.EqualTo(expected));
+        Assert.That(interp.NumericValue, Is.EqualTo(expected));
+        Assert.That(interp.StringValue, Is.EqualTo(string.Empty));
+    }
+
+    [TestCase("abs(-1)", 1)]
+    [TestCase("abs(0)", 0)]
+    [TestCase("abs(2)", 2)]
+    [TestCase("abs(-3.5)", 3.5m)]
+    [TestCase("2 + abs(-1)", 3)]
+    public void AbsoluteValue_Works(string expr, decimal expected)
+    {
+        var result = _interp.Interpret(expr);
+        AssertSuccess(result, expected, _interp);
+    }
+
+    [TestCase("sign(5)", 1)]
+    [TestCase("sign(0)", 1)]
+    [TestCase("sign(-2)", -1)]
+    [TestCase("2*sign(-3)", -2)]
+    public void Sign_Works(string expr, decimal expected)
+    {
+        var result = _interp.Interpret(expr);
+        AssertSuccess(result, expected, _interp);
+    }
+
+    [TestCase("min(1,2)", 1)]
+    [TestCase("min(2,1)", 1)]
+    [TestCase("min(-3,4)", -3)]
+    [TestCase("1 + min(3,4)", 4)]
+    [TestCase("min(2.5, 2.6)", 2.5m)]
+    public void Min_Works(string expr, decimal expected)
+    {
+        var result = _interp.Interpret(expr);
+        AssertSuccess(result, expected, _interp);
+    }
+
+    [TestCase("max(1,2)", 2)]
+    [TestCase("max(2,1)", 2)]
+    [TestCase("max(-3,4)", 4)]
+    [TestCase("1 + max(3,4)", 5)]
+    [TestCase("max(2.5, 2.6)", 2.6m)]
+    public void Max_Works(string expr, decimal expected)
+    {
+        var result = _interp.Interpret(expr);
+        AssertSuccess(result, expected, _interp);
+    }
+
+    [TestCase("pi", 3.1415926535897931m)]
+    [TestCase("e", 2.7182818284590451m)]
+    [TestCase("tau", 6.2831853071795862m)]
+    [TestCase("phi", 1.6180339887498948m)]
+    [TestCase("goldenratio", 1.6180339887498948m)]
+    [TestCase("eurler", 0.5772156649015329m)]
+    [TestCase("omega", 0.5671432904097839m)]
+    public void Constants_AreAvailable(string expr, decimal expected)
+    {
+        var result = _interp.Interpret(expr);
+        AssertSuccess(result, expected, _interp);
+    }
+
+    [Test]
+    public void Constants_CanBeUsedInArithmetic()
+    {
+        AssertSuccess(_interp.Interpret("2*pi"), 6.2831853071795862m, _interp);
+        AssertSuccess(_interp.Interpret("pi + e"), 5.8598744820488382m, _interp);
+        AssertSuccess(_interp.Interpret("tau / pi"), 2m, _interp);
+    }
+}