Refactor on weight

Author: danitome24

src/PhpValueObject/Person/Grams.php

@@ -0,0 +1,56 @@
+<?php
+/**
+ * This software was built by:
+ * Daniel Tomé Fernández <[email protected]>
+ * GitHub: danitome24
+ */
+
+namespace PhpValueObject\Person;
+
+final class Grams extends Weight
+{
+    /**
+     * Named constructor
+     *
+     * @param float $weight
+     * @return static
+     * @throws \PhpValueObject\Person\Exception\WeightNotValidException
+     */
+    public static function fromGrams(float $weight)
+    {
+        return new static($weight);
+    }
+
+    /**
+     * To Kg
+     *
+     * @return mixed
+     * @throws \PhpValueObject\Person\Exception\WeightNotValidException
+     */
+    public function toKilograms(): Kilograms
+    {
+        return Kilograms::fromKg($this->weight() / 1000);
+    }
+
+    /**
+     * To pounds
+     *
+     * @return mixed
+     * @throws \PhpValueObject\Person\Exception\WeightNotValidException
+     */
+    public function toPounds(): Pounds
+    {
+        return Pounds::fromPounds($this->weight() * 0.0022);
+    }
+
+    /**
+     * To grams
+     *
+     * @return mixed
+     * @throws \PhpValueObject\Person\Exception\WeightNotValidException
+     */
+    public function toGrams(): self
+    {
+        return new static($this->weight());
+    }
+}

src/PhpValueObject/Person/Kilograms.php

@@ -0,0 +1,83 @@
+<?php
+/**
+ * This software was built by:
+ * Daniel Tomé Fernández <[email protected]>
+ * GitHub: danitome24
+ */
+
+namespace PhpValueObject\Person;
+
+use PhpValueObject\Person\Exception\WeightNotValidException;
+
+final class Kilograms extends Weight
+{
+    const MIN_KG = 0;
+    const MAX_KG = 200;
+
+    /**
+     * Kilograms constructor.
+     * @param float $weight
+     * @throws \PhpValueObject\Person\Exception\WeightNotValidException
+     */
+    protected function __construct($weight)
+    {
+        $this->checkIsValidWeight($weight);
+        parent::__construct($weight);
+    }
+
+    /**
+     * Named constructor
+     *
+     * @param float $weight
+     * @return static
+     * @throws \PhpValueObject\Person\Exception\WeightNotValidException
+     */
+    public static function fromKg(float $weight): self
+    {
+        return new static($weight);
+    }
+
+    /**
+     * To Kg
+     *
+     * @return mixed
+     * @throws \PhpValueObject\Person\Exception\WeightNotValidException
+     */
+    public function toKilograms(): self
+    {
+        return static::fromKg($this->weight());
+    }
+
+    /**
+     * To pounds
+     *
+     * @return mixed
+     * @throws \PhpValueObject\Person\Exception\WeightNotValidException
+     */
+    public function toPounds(): Pounds
+    {
+        return Pounds::fromPounds($this->weight() * 2.2046);
+    }
+
+    /**
+     * To grams
+     *
+     * @return mixed
+     * @throws \PhpValueObject\Person\Exception\WeightNotValidException
+     */
+    public function toGrams(): Grams
+    {
+        return Grams::fromGrams($this->weight() * 1000);
+    }
+
+    /**
+     * @param float $kg
+     * @throws WeightNotValidException
+     */
+    private function checkIsValidWeight(float $kg): void
+    {
+        if ($kg < self::MIN_KG || $kg > self::MAX_KG) {
+            throw new WeightNotValidException('Weight ' . $kg . ' is not valid');
+        }
+    }
+}

src/PhpValueObject/Person/Pounds.php

@@ -0,0 +1,56 @@
+<?php
+/**
+ * This software was built by:
+ * Daniel Tomé Fernández <[email protected]>
+ * GitHub: danitome24
+ */
+
+namespace PhpValueObject\Person;
+
+final class Pounds extends Weight
+{
+    /**
+     * Named constructor
+     *
+     * @param float $weight
+     * @return static
+     * @throws \PhpValueObject\Person\Exception\WeightNotValidException
+     */
+    public static function fromPounds(float $weight): self
+    {
+        return new static($weight);
+    }
+
+    /**
+     * To Kg
+     *
+     * @return mixed
+     * @throws \PhpValueObject\Person\Exception\WeightNotValidException
+     */
+    public function toKilograms(): Kilograms
+    {
+        return Kilograms::fromKg($this->weight() * 0.453592);
+    }
+
+    /**
+     * To pounds
+     *
+     * @return mixed
+     * @throws \PhpValueObject\Person\Exception\WeightNotValidException
+     */
+    public function toPounds(): self
+    {
+        return new static($this->weight());
+    }
+
+    /**
+     * To grams
+     *
+     * @return mixed
+     * @throws \PhpValueObject\Person\Exception\WeightNotValidException
+     */
+    public function toGrams(): Grams
+    {
+        return Grams::fromGrams($this->weight() * 453.592);
+    }
+}

src/PhpValueObject/Person/Weight.php

@@ -10,63 +10,46 @@
 use PhpValueObject\Person\Exception\WeightNotValidException;
 use PhpValueObject\ValueObject;
 
-final class Weight implements ValueObject
+abstract class Weight implements ValueObject
 {
-    const MIN_KG = 10;
-    const MAX_KG = 200;
 
     /**
      * Weight in kg
      *
      * @var float
      */
-    private $weight;
+    protected $weight;
 
     /**
      * Weight constructor.
      * @param float $weight
      * @throws \PhpValueObject\Person\Exception\WeightNotValidException
      */
-    private function __construct(float $weight)
+    protected function __construct(float $weight)
     {
-        $this->changeWeight($weight);
+        $this->weight = $weight;
     }
 
     /**
-     * Named constructor
+     * To Kg
      *
-     * @param float $weight
-     * @return Weight
-     * @throws \PhpValueObject\Person\Exception\WeightNotValidException
+     * @return mixed
      */
-    public static function fromKg(float $weight): self
-    {
-        return new static($weight);
-    }
-
-    /**
-     * @return float
-     */
-    public function inKilograms(): float
-    {
-        return $this->weight;
-    }
+    abstract public function toKilograms(): Kilograms;
 
     /**
-     * @return float
+     * To pounds
+     *
+     * @return mixed
      */
-    public function inGrams(): float
-    {
-        return $this->weight * 1000;
-    }
+    abstract public function toPounds(): Pounds;
 
     /**
-     * @return float
+     * To grams
+     *
+     * @return mixed
      */
-    public function inPounds(): float
-    {
-        return $this->weight * 2.2046;
-    }
+    abstract public function toGrams(): Grams;
 
     /**
      * Compare a value object with another one.
@@ -76,19 +59,14 @@ public function inPounds(): float
      */
     public function equals(ValueObject $valueObjectToCompare): bool
     {
-        return ($this->inKilograms() === $valueObjectToCompare->inKilograms());
+        return ($this->weight() === $valueObjectToCompare->weight());
     }
 
     /**
-     * @param float $kg
-     * @throws WeightNotValidException
+     * @return float
      */
-    private function changeWeight(float $kg)
+    public function weight(): float
     {
-        if ($kg < self::MIN_KG || $kg > self::MAX_KG) {
-            throw new WeightNotValidException('Weight ' . $kg . ' is not valid');
-        }
-
-        $this->weight = $kg;
+        return $this->weight;
     }
 }

tests/Person/WeightTest.php

@@ -9,46 +9,64 @@
 
 use PHPUnit\Framework\TestCase;
 use PhpValueObject\Person\Exception\WeightNotValidException;
+use PhpValueObject\Person\Grams;
+use PhpValueObject\Person\Kilograms;
+use PhpValueObject\Person\Pounds;
 use PhpValueObject\Person\Weight;
 
 class WeightTest extends TestCase
 {
-    public function testWeightNotValidExceptionIsThrown()
+    public function testPoundsIsBuild()
     {
-        $this->expectException(WeightNotValidException::class);
+        $pounds = 4.5;
+        $poundsInstance = Pounds::fromPounds($pounds);
+        $this->assertEquals($pounds, $poundsInstance->weight());
+        $this->assertEquals(Grams::fromGrams(2041.164), $poundsInstance->toGrams());
+        $this->assertEquals(Kilograms::fromKg(2.041164), $poundsInstance->toKilograms());
+        $this->assertEquals(Pounds::fromPounds($pounds), $poundsInstance->toPounds());
+    }
 
-        Weight::fromKg(2.34);
+    public function testKilogramsIsBuild()
+    {
+        $kg = 87.7;
+        $kilograms = Kilograms::fromKg($kg);
+        $this->assertEquals($kg, $kilograms->weight());
+        $this->assertEquals(Grams::fromGrams($kg * 1000), $kilograms->toGrams());
+        $this->assertEquals(Pounds::fromPounds(193.34342), $kilograms->toPounds());
+        $this->assertEquals(Kilograms::fromKg($kg), $kilograms->toKilograms());
     }
 
-    public function testWeightIsValidInstance()
+    public function testNotValidKilogramsException()
     {
-        $weightInKg = 90.5;
-        $weightInPounds = $weightInKg * 2.2046;
-        $weight = Weight::fromKg($weightInKg);
-        $this->assertEquals($weightInKg, $weight->inKilograms());
-        $this->assertEquals($weightInKg * 1000, $weight->inGrams());
-        $this->assertEquals($weightInPounds, $weight->inPounds());
+        $this->expectException(WeightNotValidException::class);
+        Kilograms::fromKg(-4.1);
+    }
+
+    public function testGramsIsBuild()
+    {
+        $grams = 87700;
+        $grms = Grams::fromGrams($grams);
+        $this->assertEquals(Kilograms::fromKg(87.7), $grms->toKilograms());
+        $this->assertEquals(Pounds::fromPounds(192.94), $grms->toPounds());
+        $this->assertEquals(Grams::fromGrams($grams), $grms->toGrams());
     }
 
     /**
      * @dataProvider weights
      * @param Weight $weight
-     * @param Weight $otherWeight
+     * @param Weight $weightToCompare
      * @param bool $isEquals
      */
-    public function testEqualsMethod(Weight $weight, Weight $otherWeight, bool $isEquals)
+    public function testEqualsMethod(Weight $weight, Weight $weightToCompare, bool $isEquals)
     {
-        $this->assertEquals($weight->equals($otherWeight), $isEquals);
+        $this->assertEquals($isEquals, $weight->equals($weightToCompare));
     }
 
-    /**
-     * @return array
-     */
-    public function weights(): array
+    public function weights()
     {
         return [
-            [Weight::fromKg(25.98), Weight::fromKg(23.2), false],
-            [Weight::fromKg(25.98), Weight::fromKg(25.98), true]
+            [Grams::fromGrams(123), Grams::fromGrams(123), true],
+            [Grams::fromGrams(111), Grams::fromGrams(123), false]
         ];
     }
 }