Merge pull request #6 from miroiu/feature/boolean-math

miroiu · web-flow · commit 4aae7cb9c885 · 2023-11-02T19:38:30.000+02:00
Added boolean math sample unit tests
diff --git a/StringMath.Tests/BooleanExprTests.cs b/StringMath.Tests/BooleanExprTests.cs
@@ -0,0 +1,81 @@
+﻿using NUnit.Framework;
+using System;
+
+namespace StringMath.Tests
+{
+    [TestFixture]
+    internal class BooleanExprTests
+    {
+        private MathContext _context;
+
+        [SetUp]
+        public void Setup()
+        {
+            MathExpr.AddVariable("true", 1);
+            MathExpr.AddVariable("false", 0);
+
+            _context = new MathContext();
+            _context.RegisterLogical("and", (a, b) => a && b, Precedence.Multiplication);
+            _context.RegisterLogical("or", (a, b) => a || b, Precedence.Addition);
+            _context.RegisterLogical(">", (a, b) => a > b, Precedence.Power);
+            _context.RegisterLogical("<", (a, b) => a < b, Precedence.Power);
+            _context.RegisterLogical("!", (a) => !a);
+        }
+
+        [Test]
+        public void Evaluate_Variable_Substitution()
+        {
+            MathExpr expr = new MathExpr("{a} and 1", _context);
+            Assert.IsFalse(expr.Substitute("a", false).EvalBoolean());
+            Assert.IsTrue(expr.Substitute("a", true).EvalBoolean());
+        }
+
+        [Test]
+        public void Evaluate_Boolean_Numbers()
+        {
+            bool expr = "1 and 1".EvalBoolean(_context);
+            Assert.IsTrue(expr);
+
+            bool result = "1 and 0 or !0 and 3 > 2".EvalBoolean(_context);
+            Assert.IsTrue(result);
+        }
+
+        [Test]
+        public void Evaluate_Globals_Variables()
+        {
+            Assert.IsTrue("{true} or {false} and {true}".EvalBoolean(_context));
+            Assert.IsTrue("{true} or {false}".EvalBoolean(_context));
+            Assert.IsFalse("{false} or {false}".EvalBoolean(_context));
+            Assert.IsFalse("{true} and {false}".EvalBoolean(_context));
+            Assert.IsTrue("{true} and {true}".EvalBoolean(_context));
+        }
+
+        [Test]
+        public void Evaluate_Binary_Operation()
+        {
+            _context.RegisterBinary("+", (a, b) => a + b);
+            Assert.IsTrue("(3 + 5) > 7".EvalBoolean(_context));
+        }
+    }
+
+    static class BooleanMathExtensions
+    {
+        public static bool EvalBoolean(this string value) => value.ToMathExpr().EvalBoolean();
+
+        public static bool EvalBoolean(this string value, IMathContext context) => value.ToMathExpr(context).EvalBoolean();
+
+        public static bool EvalBoolean(this MathExpr value) => value.Result != 0;
+
+        public static MathExpr Substitute(this MathExpr expr, string name, bool value)
+            => expr.Substitute(name, value is true ? 1 : 0);
+
+        public static void RegisterLogical(this IMathContext context, string operatorName, Func<bool, bool, bool> operation, Precedence? precedence)
+            => context.RegisterBinary(operatorName, (a, b) => operation(a != 0, b != 0) ? 1 : 0, precedence);
+
+        public static void RegisterLogical(this IMathContext context, string operatorName, Func<double, double, bool> operation, Precedence? precedence)
+            => context.RegisterBinary(operatorName, (a, b) => operation(a, b) ? 1 : 0, precedence);
+
+        public static void RegisterLogical(this IMathContext context, string operatorName, Func<bool, bool> operation)
+            => context.RegisterUnary(operatorName, (a) => operation(a != 0) ? 1 : 0);
+    }
+}
