Throw exception if more than one value is passed to a unit upon initi…

…alization

README.md

@@ -58,7 +58,7 @@ preference set, but can be overridden when instantiating a new unit.
     'Temperature' => 'Fahrenheit',
     'Volume' => 'Gallon',
     'Pressure' => 'Psi',
-    'Weight' => 'Pound'
+    'Weight' => 'Pound',
     'Color' => 'Srm',
 ]
 ```

src/AbstractUnit.php

@@ -39,6 +39,22 @@ public function getValue(?int $round = null): float
         throw new RuntimeException("Unit '$gatherMethod' does not exist.");
     }
 
+    /**
+     * @param array $values
+     * @return bool
+     */
+    public function hasOnlyOneValue(array $values): bool
+    {
+        $count = 0;
+        foreach ($values as $value) {
+            if (!is_null($value)) {
+                $count++;
+            }
+        }
+
+        return $count === 1;
+    }
+
     /**
      * @return string
      * @throws \RuntimeException

src/Color.php

@@ -14,6 +14,10 @@ public function __construct(
         ?float $lovibond = null,
         array $preferences = []
     ) {
+        if (!$this->hasOnlyOneValue([$srm, $ebc, $lovibond])) {
+            throw new \InvalidArgumentException('Only one Color type can be set at a time.');
+        }
+
         parent::__construct($preferences);
 
         if ($srm) {

src/Gravity.php

@@ -16,6 +16,10 @@ public function __construct(
         float $brix = null,
         array $preferences = []
     ) {
+        if (!$this->hasOnlyOneValue([$plato, $specificGravity, $brix])) {
+            throw new \InvalidArgumentException('Only one Gravity type can be set at a time.');
+        }
+
         parent::__construct($preferences);
 
         if ($plato) {
@@ -97,18 +101,30 @@ public function setBrix(float $brix): self
         return $this;
     }
 
+    /**
+     * @param float $plato
+     * @return float
+     */
     public static function convertPlatoToSpecificGravity(float $plato): float
     {
         return 259 / (259 - $plato);
     }
 
+    /**
+     * @param float $plato
+     * @return float
+     */
     public static function convertPlatoToBrix(float $plato): float
     {
         $specificGravity = self::convertPlatoToSpecificGravity($plato);
 
         return self::convertSpecificGravityToBrix($specificGravity);
     }
 
+    /**
+     * @param float $specificGravity
+     * @return float
+     */
     public static function convertSpecificGravityToPlato(float $specificGravity): float
     {
         return 259 - (259 / $specificGravity);

src/Pressure.php

@@ -9,6 +9,10 @@ class Pressure extends AbstractUnit
 
     public function __construct(?float $bar = null, ?float $psi = null, array $preferences = [])
     {
+        if (!$this->hasOnlyOneValue([$bar, $psi])) {
+            throw new \InvalidArgumentException('Only one Pressure type can be set at a time.');
+        }
+
         parent::__construct($preferences);
 
         if ($bar) {

src/Temperature.php

@@ -9,6 +9,10 @@ class Temperature extends AbstractUnit
 
     public function __construct(float $fahrenheit = null, float $celsius = null, array $preferences = [])
     {
+        if (!$this->hasOnlyOneValue([$fahrenheit, $celsius])) {
+            throw new \InvalidArgumentException('Only one Temperature type can be set at a time.');
+        }
+
         parent::__construct($preferences);
 
         if ($fahrenheit) {

src/Volume.php

@@ -20,6 +20,10 @@ public function __construct(
         float $hectoliter = null,
         array $preferences = []
     ) {
+        if (!$this->hasOnlyOneValue([$ounce, $gallon, $barrel, $milliliter, $liter, $hectoliter])) {
+            throw new \InvalidArgumentException('Only one Volume type can be set at a time.');
+        }
+
         parent::__construct($preferences);
 
         if ($ounce) {

src/Weight.php

@@ -16,6 +16,10 @@ public function __construct(
         ?float $kilogram = null,
         array $preferences = []
     ) {
+        if (!$this->hasOnlyOneValue([$ounce, $pound, $gram, $kilogram])) {
+            throw new \InvalidArgumentException('Only one Weight type can be set at a time.');
+        }
+
         parent::__construct($preferences);
 
         if ($ounce) {

tests/ColorTest.php

@@ -91,4 +91,20 @@ public function testSetLovibondWillReturnSrmWithGetValueAndDefaultPreferences():
 
         $this->assertEquals($expected, $actual);
     }
+
+    public function testWillThrowExceptionWithNoValuesSet(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Only one Color type can be set at a time.');
+
+        new Color();
+    }
+
+    public function testWillThrowExceptionWithTooManyValuesSet(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Only one Color type can be set at a time.');
+
+        new Color(srm: self::TEST_SRM, ebc: self::TEST_EBC);
+    }
 }

tests/GravityTest.php

@@ -121,4 +121,20 @@ public function testSetBrixWillReturnBrixWithGetBrix(): void
 
         $this->assertEquals($expected, $actual);
     }
+
+    public function testWillThrowExceptionWithNoValuesSet(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Only one Gravity type can be set at a time.');
+
+        new Gravity();
+    }
+
+    public function testWillThrowExceptionWithTooManyValuesSet(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Only one Gravity type can be set at a time.');
+
+        new Gravity(plato: self::TEST_PLATO, specificGravity: self::TEST_SPECIFIC_GRAVITY);
+    }
 }

tests/PressureTest.php

@@ -63,4 +63,20 @@ public function testSetBarWillReturnBarWithGetBar(): void
 
         $this->assertEquals($expected, $actual);
     }
+
+    public function testWillThrowExceptionWithNoValuesSet(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Only one Pressure type can be set at a time.');
+
+        new Pressure();
+    }
+
+    public function testWillThrowExceptionWithTooManyValuesSet(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Only one Pressure type can be set at a time.');
+
+        new Pressure(bar: self::TEST_BAR, psi: self::TEST_PSI);
+    }
 }

tests/TemperatureTest.php

@@ -63,4 +63,20 @@ public function testSetCelsiusWillReturnCelsiusWithGetCelsius(): void
 
         $this->assertEquals($expected, $actual);
     }
+
+    public function testWillThrowExceptionWithNoValuesSet(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Only one Temperature type can be set at a time.');
+
+        new Temperature();
+    }
+
+    public function testWillThrowExceptionWithTooManyValuesSet(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Only one Temperature type can be set at a time.');
+
+        new Temperature(celsius: self::TEST_CELSIUS, fahrenheit: self::TEST_FAHRENHEIT);
+    }
 }

tests/VolumeTest.php

@@ -358,4 +358,20 @@ public function testSetHectoliterWillReturnHectoliterWithGetHectoliter(): void
 
         $this->assertEquals($expected, $actual);
     }
+
+    public function testWillThrowExceptionWithNoValuesSet(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Only one Volume type can be set at a time.');
+
+        new Volume();
+    }
+
+    public function testWillThrowExceptionWithTooManyValuesSet(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Only one Volume type can be set at a time.');
+
+        new Volume(gallon: self::TEST_GALLON, liter: self::TEST_LITER);
+    }
 }

tests/WeightTest.php

@@ -172,4 +172,20 @@ public function testSetKilogramWillReturnKilogramWithGetKilogram(): void
 
         $this->assertEquals($expected, $actual);
     }
+
+    public function testWillThrowExceptionWithNoValuesSet(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Only one Weight type can be set at a time.');
+
+        new Weight();
+    }
+
+    public function testWillThrowExceptionWithTooManyValuesSet(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Only one Weight type can be set at a time.');
+
+        new Weight(pound: self::TEST_POUND, ounce: self::TEST_OUNCE);
+    }
 }