Call simplify before toFloat conversion (#73)

brick · Aug 10, 2022 · d54a395 · d54a395
1 parent de84657
commit d54a395
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Showing 2 changed files with 34 additions and 1 deletion.
diff --git a/src/BigRational.php b/src/BigRational.php
@@ -429,7 +429,8 @@ public function toInt() : int
      */
     public function toFloat() : float
     {
-        return $this->numerator->toFloat() / $this->denominator->toFloat();
+        $simplified = $this->simplified();
+        return $simplified->numerator->toFloat() / $simplified->denominator->toFloat();
     }
 
     /**

diff --git a/tests/BigRationalTest.php b/tests/BigRationalTest.php
@@ -892,6 +892,38 @@ public function providerToIntThrowsException() : array
         ];
     }
 
+    public function testIdentityOperationResultsInDifferentToFloatValueWithoutSimplification() : void
+    {
+        $expectedValue = 11.46;
+        $conversionFactor = BigRational::of('0.45359237');
+        $value = BigRational::of($expectedValue);
+
+        $identicalValueAfterMathOperations = $value->multipliedBy($conversionFactor)
+            ->dividedBy($conversionFactor)
+            ->multipliedBy($conversionFactor)
+            ->dividedBy($conversionFactor)
+            ->multipliedBy($conversionFactor)
+            ->dividedBy($conversionFactor);
+
+        self::assertSame($expectedValue, $identicalValueAfterMathOperations->toFloat());
+
+        // Assert that simplification is required and the test would fail without it
+        self::assertNotSame(
+            $expectedValue,
+            $identicalValueAfterMathOperations->getNumerator()->toFloat() / $identicalValueAfterMathOperations->getDenominator()->toFloat(),
+        );
+    }
+
+    public function testToFloatConversionPerformsSimplificationToPreventOverflow() : void
+    {
+        $int = BigInteger::of('1e4000');
+        $val = BigRational::nd($int, $int);
+
+        self::assertInfinite($val->getNumerator()->toFloat());
+        // Assert that simplification is required and the test would fail without it
+        self::assertSame(1.0, $val->toFloat());
+    }
+
     /**
      * @dataProvider providerToFloat
      *