Merge pull request #4 from Jagdish-J-P/patch-1

Added method to reset points collection

examples/index.php

@@ -46,3 +46,31 @@
 
 // Output the distance in summary:
 echo "<p>Distance from Colchester to Ipswich and then straight on to Aylesbury is:  " . $distance->asKilometres(). "km (or " . $distance->asMiles() . " miles).</p>";
+
+// Reset the points and add new ones...
+$calculator = new Calculator();
+$calculator->addPoint($centralIpswich);
+$calculator->addPoint($centralAylesbury);
+$calculator->resetPoints();
+$calculator->addPoint($centralAylesbury);
+$calculator->addPoint($centralColchester);
+
+$distance = $calculator->get();
+
+// Output the distance in summary:
+echo "<p>Distance from Aylesbury to Colchester is:  " . $distance->asKilometres(). "km (or " . $distance->asMiles() . " miles).</p>";
+
+// Reset the points with calculations and calculate new ones...
+$calculator = new Calculator();
+$calculator->addPoint($centralIpswich);
+$calculator->addPoint($centralAylesbury);
+$distance1 = $calculator->get(true);
+
+$calculator->addPoint($centralAylesbury);
+$calculator->addPoint($centralColchester);
+
+$distance2 = $calculator->get(true);
+
+// Output the distance in summary:
+echo "<p>Distance from Ipswich to Aylesbury is:  " . $distance1->asKilometres(). "km (or " . $distance1->asMiles() . " miles).</p>";
+echo "<p>Distance from Aylesbury to Colchester is:  " . $distance2->asKilometres(). "km (or " . $distance2->asMiles() . " miles).</p>";

src/Calculator.php

@@ -74,6 +74,16 @@ public function removePoint($key = null)
         throw new \InvalidArgumentException('The point key does not exist.');
     }
 
+    /**
+     * Resets the points collection.
+     * @return \Ballen\Distical\Calculator
+     */
+    public function resetPoints()
+    {
+        $this->points = [];
+        return $this;        
+    }
+
     /**
      * Helper method to get distance between two points.
      * @param LatLong $pointA Point A (eg. Departure point)
@@ -113,9 +123,10 @@ private function distanceBetweenPoints(LatLong $pointA, LatLong $pointB)
 
     /**
      * Calculates the distance between each of the points.
+     * @param bool $shouldResetPoints Clears points collection after calculating distance if true
      * @return double Distance in kilometres.
      */
-    private function calculate()
+    private function calculate(bool $shouldResetPoints = false)
     {
         if (count($this->points) < 2) {
             throw new \RuntimeException('There must be two or more points (co-ordinates) before a calculation can be performed.');
@@ -127,15 +138,21 @@ private function calculate()
             }
             $previous = $point;
         }
+
+        if ($shouldResetPoints === true) {
+            $this->resetPoints();
+        }
+
         return $total;
     }
 
     /**
      * Returns the total distance between the two lat/lng points.
+     * @param bool $shouldResetPoints Resets points collection after calculating distance if true
      * @return Distance
      */
-    public function get()
+    public function get(bool $shouldResetPoints = false)
     {
-        return new Distance($this->calculate());
+        return new Distance($this->calculate($shouldResetPoints));
     }
 }

src/Entities/Distance.php

@@ -37,9 +37,9 @@ class Distance
      * Class constructor
      * @param mixed $kilometres The distance in kilometres.
      */
-    public function __construct($kilometres = 0)
+    public function __construct($kilometres = 0, $allowZero = false)
     {
-        $this->validateDistance($kilometres);
+        $this->validateDistance($kilometres, $allowZero);
         $this->kilometres = $kilometres;
     }
 
@@ -49,14 +49,19 @@ public function __construct($kilometres = 0)
      * @throws \InvalidArgumentException
      * @return void
      */
-    private function validateDistance($distance)
+    private function validateDistance($distance, $allowZero = false)
     {
         if (!is_numeric($distance)) {
             throw new \InvalidArgumentException('The distance value must be of a valid type.');
         }
-        if (!$distance > 0) {
+
+        if (!$allowZero && $distance === 0) {
             throw new \InvalidArgumentException('The distance must be greater than zero!');
         }
+
+        if ($distance < 0) {
+            throw new \InvalidArgumentException('The distance must be greater than or equals zero!');
+        }
     }
 
     /**

tests/DistanceEntityTest.php

@@ -36,14 +36,27 @@ public function testEntityCreation()
 
     public function testInvalidEntityCreationWithAsString()
     {
-        $this->expectException('InvalidArgumentException', 'The distance value must be of a valid type.');
-        $test = new Distance('a random string');
+        $this->expectExceptionMessage('The distance value must be of a valid type.');
+        new Distance('a random string');
     }
 
     public function testInvalidEntityCreationWithZero()
     {
-        $this->expectException('InvalidArgumentException', 'The distance must be greater than zero!');
-        $test = new Distance(0);
+        $this->expectExceptionMessage('The distance must be greater than zero!');
+        new Distance(0);
+    }
+
+    public function testInvalidEntityCreationWithNegative()
+    {
+        $this->expectExceptionMessage('The distance must be greater than or equals zero!');
+        new Distance(-1, true);
+    }
+
+    public function testEntityCreationWithAllowedZero()
+    {
+        $test = new Distance(0, true);
+        $this->assertInstanceOf(Distance::class, $test);
+        $this->assertEquals(0, $test->asKilometres());
     }
 
     public function testConversionToKilometres()

tests/DisticalTest.php

@@ -79,6 +79,51 @@ public function testRemovePointWithKey()
         $calculator->get();
     }
 
+    public function testResetPoints()
+    {
+        $calculator = new Calculator();
+        $calculator->addPoint($this->latlong1);
+        $calculator->addPoint($this->latlong2);
+        $this->assertInstanceOf(Distance::class, $calculator->get());
+
+        $calculator->resetPoints();
+        $calculator->addPoint($this->latlong3);
+        $this->expectExceptionMessage(
+            'There must be two or more points (co-ordinates) before a calculation can be performed.'
+        );
+        $calculator->get();
+
+        $calculator->addPoint($this->latlong2);
+        $this->assertEquals(6.273748050460542, $calculator->get()->asKilometres());
+    }
+
+    public function testCalculationsAfterResetPoints()
+    {
+        $calculator = new Calculator();
+        $calculator->addPoint($this->latlong1);
+        $calculator->addPoint($this->latlong2);
+        $calculator->resetPoints();
+        $calculator->addPoint($this->latlong2);
+        $calculator->addPoint($this->latlong3);
+
+        $this->assertEquals(6.273748050460542, $calculator->get()->asKilometres());
+        $this->assertNotEquals(9.444924713131321, $calculator->get()->asKilometres());
+    }
+
+    public function testResetPointsAfterCalculation()
+    {
+        $calculator = new Calculator();
+        $calculator->addPoint($this->latlong1);
+        $calculator->addPoint($this->latlong2);
+        $this->assertInstanceOf(Distance::class, $calculator->get(true));
+
+        $calculator->addPoint($this->latlong3);
+        $this->expectExceptionMessage(
+            'There must be two or more points (co-ordinates) before a calculation can be performed.'
+        );
+        $calculator->get();
+    }
+
     public function testRemovePointWithInvalidKey()
     {
         $this->expectExceptionMessage('The point key does not exist.');