From d3685e384ff2ca0cb698e19b746132aca021a739 Mon Sep 17 00:00:00 2001
From: Luc De Brouwer <info@lucdebrouwer.nl>
Date: Sun, 22 Feb 2026 13:26:26 +0000
Subject: [PATCH 01/11] Update minimum required PHP version, PHPUnit, and
 tests.

---
 .gitignore             |  5 ++-
 composer.json          |  6 +--
 phpunit.xml            | 31 ++++++++------
 src/Distance.php       |  6 ++-
 tests/DistanceTest.php | 95 +++++++++++++++++++-----------------------
 5 files changed, 72 insertions(+), 71 deletions(-)

diff --git a/.gitignore b/.gitignore
index 9e270ad..0f0f75e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,6 @@
+.idea
 composer.phar
 composer.lock
-vendor/
\ No newline at end of file
+vendor/
+.phpunit.cache
+.phpunit.result.cache
\ No newline at end of file
diff --git a/composer.json b/composer.json
index 02b010b..e5a2909 100644
--- a/composer.json
+++ b/composer.json
@@ -22,10 +22,10 @@
     }
   ],
   "require": {
-    "php": ">=5.5"
+    "php": ">=8.4"
   },
   "require-dev": {
-    "phpunit/phpunit": "4.6.*"
+    "phpunit/phpunit": "^13.0"
   },
   "extra": {
     "branch-alias": {
@@ -35,4 +35,4 @@
   "autoload": {
     "psr-4": {"LucDeBrouwer\\Distance\\": "src/"}
   }
-}
\ No newline at end of file
+}
diff --git a/phpunit.xml b/phpunit.xml
index 6df70d2..a3722f2 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -1,18 +1,23 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<phpunit backupGlobals="false"
-         backupStaticAttributes="false"
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="vendor/phpunit/phpunit/phpunit.xsd"
          bootstrap="vendor/autoload.php"
-         colors="true"
-         convertErrorsToExceptions="true"
-         convertNoticesToExceptions="true"
-         convertWarningsToExceptions="true"
-         processIsolation="false"
-         stopOnFailure="false"
-         syntaxCheck="false"
-        >
+         cacheDirectory=".phpunit.cache"
+         executionOrder="depends,defects"
+         beStrictAboutOutputDuringTests="true"
+         displayDetailsOnPhpunitDeprecations="true"
+         failOnPhpunitDeprecation="true"
+         failOnRisky="true"
+         failOnWarning="true">
     <testsuites>
-        <testsuite name="Package Test Suite">
-            <directory suffix=".php">./tests/</directory>
+        <testsuite name="default">
+            <directory>tests</directory>
         </testsuite>
     </testsuites>
-</phpunit>
\ No newline at end of file
+
+    <source ignoreIndirectDeprecations="true" restrictNotices="true" restrictWarnings="true">
+        <include>
+            <directory>src</directory>
+        </include>
+    </source>
+</phpunit>
diff --git a/src/Distance.php b/src/Distance.php
index d0eb5c2..d226073 100644
--- a/src/Distance.php
+++ b/src/Distance.php
@@ -1,4 +1,8 @@
-<?php namespace LucDeBrouwer\Distance;
+<?php
+
+declare(strict_types=1);
+
+namespace LucDeBrouwer\Distance;
 
 use \Exception;
 
diff --git a/tests/DistanceTest.php b/tests/DistanceTest.php
index e05abdd..5ac711c 100644
--- a/tests/DistanceTest.php
+++ b/tests/DistanceTest.php
@@ -1,132 +1,121 @@
 <?php
 
+declare(strict_types=1);
+
 use LucDeBrouwer\Distance\Distance;
+use PHPUnit\Framework\Attributes\Test;
+use PHPUnit\Framework\TestCase;
 
-/**
- * Class DistanceTest
- */
-class DistanceTest extends PHPUnit_Framework_TestCase
+class DistanceTest extends TestCase
 {
-
-    /**
-     * Test the setting and getting of the distance unit.
-     */
-    public function testUnit()
+    #[Test]
+    public function canSetUnit(): void
     {
         $distance = new Distance();
         $distance->setUnit('mi');
 
-        $this->assertEquals('mi', $distance->getUnit());
+        $this->assertSame('mi', $distance->getUnit());
     }
 
-    /**
-     * Test the throwing of an exception in case we try to set an invalid unit.
-     *
-     * @expectedException Exception
-     */
-    public function testInvalidUnit()
+    #[Test]
+    public function willThrowExceptionInCaseWeSetAnInvalidUnit(): void
     {
+        $this->expectException(Exception::class);
+        $this->expectExceptionMessage('You have tried to set an invalid distance unit.');
+
         $distance = new Distance();
 
         $distance->setUnit('mm');
     }
 
-    /**
-     * Test the setting and getting of the distance formula.
-     */
-    public function testFormula()
+    #[Test]
+    public function canSetFormula(): void
     {
         $distance = new Distance();
         $distance->setFormula('vincenty');
 
-        $this->assertEquals('vincenty', $distance->getFormula());
+        $this->assertSame('vincenty', $distance->getFormula());
     }
 
-    /**
-     * Test the throwing of an exception in case we try to set an invalid formula.
-     *
-     * @expectedException Exception
-     */
-    public function testInvalidFormula()
+    #[Test]
+    public function willThrowExceptionInCaseWeSetAnInvalidFormula(): void
     {
+        $this->expectException(Exception::class);
+        $this->expectExceptionMessage('You have tried to set an invalid distance formula.');
+
         $distance = new Distance();
 
         $distance->setFormula('Leonardo');
     }
 
-    /**
-     * Test the throwing of an exception in case an invalid parameter is being passed.
-     *
-     * @expectedException Exception
-     */
-    public function testInvalidParams()
+    #[Test]
+    public function willThrowAnExceptionInCaseWeProvideInvalidParameters(): void
     {
+        $this->expectException(Exception::class);
+        $this->expectExceptionMessage('One or more of the parsed variables are not valid floats.');
+
         $distance = new Distance();
 
         $distance->between('1', 1, 'not a float', 'invalid');
     }
 
-    /**
-     * Test the retrieval of the distance between the Apple and Google campuses using the Vincenty formula.
-     */
-    public function testDistanceBetweenAppleAndGoogleUsingVincenty()
+    #[Test]
+    public function canConvertDistanceUsingVincentyFormula(): void
     {
         $distance = new Distance();
         $distance->setUnit('m');
         $distance->setFormula('vincenty');
 
-        $this->assertEquals(11164, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
+        $this->assertSame(11164.0, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
 
         $distance->setUnit('km');
 
-        $this->assertEquals(11.164, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
+        $this->assertSame(11.164, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
 
         $distance->setUnit('mi');
 
-        $this->assertEquals(6.936987987488, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
+        $this->assertSame(6.936987987488, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
 
         $distance->setUnit('cm');
 
-        $this->assertEquals(1116400, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
+        $this->assertSame(1116400.0, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
 
         $distance->setUnit('ft');
 
-        $this->assertEquals(36627.2966436, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
+        $this->assertSame(36627.2966436, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
 
         $distance->setUnit('in');
 
-        $this->assertEquals(439527.5586068, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
+        $this->assertSame(439527.5586068, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
     }
 
-    /**
-     * Test the retrieval of the distance between the Apple and Google campuses using the Haversine formula.
-     */
-    public function testDistanceBetweenAppleAndGoogleUsingHaversine()
+    #[Test]
+    public function canConvertDistanceUsingHaversineFormula(): void
     {
         $distance = new Distance();
         $distance->setUnit('m');
         $distance->setFormula('haversine');
 
-        $this->assertEquals(11164, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
+        $this->assertSame(11164.0, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
 
         $distance->setUnit('km');
 
-        $this->assertEquals(11.164, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
+        $this->assertSame(11.164, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
 
         $distance->setUnit('mi');
 
-        $this->assertEquals(6.936987987488, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
+        $this->assertSame(6.936987987488, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
 
         $distance->setUnit('cm');
 
-        $this->assertEquals(1116400, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
+        $this->assertSame(1116400.0, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
 
         $distance->setUnit('ft');
 
-        $this->assertEquals(36627.2966436, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
+        $this->assertSame(36627.2966436, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
 
         $distance->setUnit('in');
 
-        $this->assertEquals(439527.5586068, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
+        $this->assertSame(439527.5586068, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
     }
 }
\ No newline at end of file

From eeef1129ef7bbf0ac1b7b8780e43363b40490336 Mon Sep 17 00:00:00 2001
From: Luc De Brouwer <info@lucdebrouwer.nl>
Date: Sun, 22 Feb 2026 15:27:17 +0000
Subject: [PATCH 02/11] Introduce PHPStan, PHPCS, clean up code.

---
 .gitignore             |   1 +
 composer.json          |  22 ++++++-
 phpcs.xml              | 132 +++++++++++++++++++++++++++++++++++++++++
 phpstan.neon           |  12 ++++
 src/Distance.php       | 124 +++++++++++---------------------------
 tests/DistanceTest.php |  20 ++-----
 6 files changed, 205 insertions(+), 106 deletions(-)
 create mode 100644 phpcs.xml
 create mode 100644 phpstan.neon

diff --git a/.gitignore b/.gitignore
index 0f0f75e..edede23 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,5 +2,6 @@
 composer.phar
 composer.lock
 vendor/
+storage/
 .phpunit.cache
 .phpunit.result.cache
\ No newline at end of file
diff --git a/composer.json b/composer.json
index e5a2909..bbe0326 100644
--- a/composer.json
+++ b/composer.json
@@ -25,7 +25,13 @@
     "php": ">=8.4"
   },
   "require-dev": {
-    "phpunit/phpunit": "^13.0"
+    "phpunit/phpunit": "^13.0",
+    "phpstan/phpstan": "^2.1",
+    "phpstan/phpstan-phpunit": "^2.0",
+    "roave/security-advisories": "dev-latest",
+    "phpstan/phpstan-strict-rules": "^2.0",
+    "squizlabs/php_codesniffer": "^4.0",
+    "slevomat/coding-standard": "^8.27"
   },
   "extra": {
     "branch-alias": {
@@ -33,6 +39,18 @@
     }
   },
   "autoload": {
-    "psr-4": {"LucDeBrouwer\\Distance\\": "src/"}
+    "psr-4": {
+      "LucDeBrouwer\\Distance\\": "src/"
+    }
+  },
+  "autoload-dev": {
+    "psr-4": {
+      "Tests\\LucDeBrouwer\\Distance\\": "tests/"
+    }
+  },
+  "config": {
+    "allow-plugins": {
+      "dealerdirect/phpcodesniffer-composer-installer": true
+    }
   }
 }
diff --git a/phpcs.xml b/phpcs.xml
new file mode 100644
index 0000000..d2e5a58
--- /dev/null
+++ b/phpcs.xml
@@ -0,0 +1,132 @@
+<?xml version="1.0"?>
+<ruleset name="Custom Standard">
+	<description>The coding standard for ldebrouwer/distance.</description>
+	<arg value="p"/><!--show phpunit-like progress-->
+	<arg name="colors"/>
+	<arg name="cache"/>
+	<file>src/</file>
+	<file>tests</file>
+
+	<rule ref="PSR12">
+		<exclude name="Generic.Files.LineLength"/>
+	</rule>
+	<rule ref="Generic.Arrays.DisallowLongArraySyntax"/>
+	<rule ref="Generic.PHP.ForbiddenFunctions">
+		<properties>
+			<property name="forbiddenFunctions" type="array">
+				<element key="sizeof" value="count"/>
+				<element key="delete" value="unset"/>
+				<element key="print" value="echo"/>
+				<element key="is_null" value="null"/>
+				<element key="create_function" value="null"/>
+				<element key="join" value="implode"/>
+			</property>
+		</properties>
+	</rule>
+	<rule ref="Squiz.WhiteSpace.FunctionOpeningBraceSpace"/>
+
+	<config name="installed_paths" value="../../slevomat/coding-standard"/>
+	<rule ref="SlevomatCodingStandard.Arrays.DisallowImplicitArrayCreation"/>
+	<rule ref="SlevomatCodingStandard.Arrays.MultiLineArrayEndBracketPlacement"/>
+	<rule ref="SlevomatCodingStandard.Arrays.SingleLineArrayWhitespace"/>
+	<rule ref="SlevomatCodingStandard.Arrays.TrailingArrayComma"/>
+	<rule ref="SlevomatCodingStandard.Classes.ClassConstantVisibility"/>
+	<rule ref="SlevomatCodingStandard.Classes.ClassMemberSpacing">
+		<properties>
+			<property name="linesCountBetweenMembers" value="1"/>
+		</properties>
+	</rule>
+	<rule ref="SlevomatCodingStandard.Classes.ConstantSpacing">
+		<properties>
+			<property name="minLinesCountBeforeWithComment" value="0"/>
+			<property name="maxLinesCountBeforeWithComment" value="1"/>
+			<property name="minLinesCountBeforeWithoutComment" value="0"/>
+			<property name="maxLinesCountBeforeWithoutComment" value="1"/>
+		</properties>
+	</rule>
+	<rule ref="SlevomatCodingStandard.Classes.MethodSpacing">
+		<properties>
+			<property name="minLinesCount" value="1"/>
+			<property name="maxLinesCount" value="1"/>
+		</properties>
+	</rule>
+	<rule ref="SlevomatCodingStandard.Classes.PropertyDeclaration"/>
+	<rule ref="SlevomatCodingStandard.Classes.PropertySpacing">
+		<properties>
+			<property name="minLinesCountBeforeWithComment" value="0"/>
+			<property name="maxLinesCountBeforeWithComment" value="1"/>
+			<property name="minLinesCountBeforeWithoutComment" value="0"/>
+			<property name="maxLinesCountBeforeWithoutComment" value="1"/>
+		</properties>
+	</rule>
+	<rule ref="SlevomatCodingStandard.Classes.RequireConstructorPropertyPromotion"/>
+	<rule ref="SlevomatCodingStandard.Commenting.DocCommentSpacing">
+		<properties>
+			<property name="linesCountBeforeFirstContent" value="0"/>
+			<property name="linesCountAfterLastContent" value="0"/>
+		</properties>
+		<exclude name="SlevomatCodingStandard.Commenting.DocCommentSpacing.IncorrectLinesCountBetweenDescriptionAndAnnotations"/>
+		<exclude name="SlevomatCodingStandard.Commenting.DocCommentSpacing.IncorrectLinesCountBetweenDifferentAnnotationsTypes"/>
+	</rule>
+	<rule ref="SlevomatCodingStandard.Commenting.EmptyComment" />
+	<rule ref="SlevomatCodingStandard.Commenting.ForbiddenAnnotations">
+		<properties>
+			<property name="forbiddenAnnotations" type="array">
+				<element value="@package"/>
+			</property>
+		</properties>
+	</rule>
+	<rule ref="SlevomatCodingStandard.Commenting.ForbiddenComments">
+		<properties>
+			<property name="forbiddenCommentPatterns" type="array">
+				<element value="/Created by PhpStorm/"/>
+				<element value="/^Constructor\./"/>
+				<element value="/^Class \w+/"/>
+			</property>
+		</properties>
+	</rule>
+	<rule ref="SlevomatCodingStandard.Commenting.InlineDocCommentDeclaration">
+		<properties>
+			<property name="allowAboveNonAssignment" value="true"/>
+		</properties>
+	</rule>
+	<rule ref="SlevomatCodingStandard.Commenting.UselessInheritDocComment"/>
+	<rule ref="SlevomatCodingStandard.Exceptions.DeadCatch"/>
+	<rule ref="SlevomatCodingStandard.Exceptions.RequireNonCapturingCatch"/>
+	<rule ref="SlevomatCodingStandard.Functions.RequireTrailingCommaInCall"/>
+	<rule ref="SlevomatCodingStandard.Functions.RequireTrailingCommaInDeclaration"/>
+	<rule ref="SlevomatCodingStandard.Namespaces.DisallowGroupUse"/>
+	<rule ref="SlevomatCodingStandard.Namespaces.MultipleUsesPerLine"/>
+	<rule ref="SlevomatCodingStandard.Namespaces.UnusedUses">
+		<properties>
+			<property name="searchAnnotations" value="true"/>
+			<property name="ignoredAnnotations" type="array">
+				<element value="@group"/>
+			</property>
+		</properties>
+	</rule>
+	<rule ref="SlevomatCodingStandard.Namespaces.UseDoesNotStartWithBackslash"/>
+	<rule ref="SlevomatCodingStandard.Namespaces.UseSpacing">
+		<properties>
+			<property name="linesCountBeforeFirstUse" value="1"/>
+			<property name="linesCountBetweenUseTypes" value="1"/>
+			<property name="linesCountAfterLastUse" value="1"/>
+		</properties>
+	</rule>
+	<rule ref="SlevomatCodingStandard.PHP.UselessSemicolon"/>
+	<rule ref="SlevomatCodingStandard.TypeHints.DeclareStrictTypes">
+		<properties>
+			<property name="spacesCountAroundEqualsSign" value="0"/>
+		</properties>
+	</rule>
+	<rule ref="SlevomatCodingStandard.TypeHints.LongTypeHints"/>
+	<rule ref="SlevomatCodingStandard.TypeHints.ParameterTypeHint"/>
+	<rule ref="SlevomatCodingStandard.TypeHints.ParameterTypeHintSpacing"/>
+	<rule ref="SlevomatCodingStandard.TypeHints.PropertyTypeHint"/>
+	<rule ref="SlevomatCodingStandard.TypeHints.ReturnTypeHint"/>
+	<rule ref="SlevomatCodingStandard.TypeHints.ReturnTypeHintSpacing">
+		<properties>
+			<property name="spacesCountBeforeColon" value="0"/>
+		</properties>
+	</rule>
+</ruleset>
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 0000000..a29f3a0
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,12 @@
+parameters:
+	level: max
+	paths:
+		- src
+		- tests
+	tmpDir: /var/www/html/storage/phpstan-cache
+	reportUnmatchedIgnoredErrors: true
+
+includes:
+	- vendor/phpstan/phpstan-phpunit/extension.neon
+	- vendor/phpstan/phpstan-strict-rules/rules.neon
+	- vendor/phpstan/phpstan/conf/bleedingEdge.neon
diff --git a/src/Distance.php b/src/Distance.php
index d226073..3fe030a 100644
--- a/src/Distance.php
+++ b/src/Distance.php
@@ -4,88 +4,62 @@
 
 namespace LucDeBrouwer\Distance;
 
-use \Exception;
+use RuntimeException;
 
 /**
  * Distance helps you calculate the distance between GPS coordinates, in vanilla PHP. Pure and simple.
- *
- * @package LucDeBrouwer\Distance
  */
 class Distance
 {
-
     /**
      * The formula used for distance calculation.
-     *
-     * @var string
      */
-    private $formula = 'vincenty';
+    private string $formula = 'vincenty';
 
     /**
      * The unit used to return the distance in. The supported units are shown in the conversion table below.
-     *
-     * @var string
      */
-    private $unit = 'km';
+    private string $unit = 'km';
 
     /**
      * An array holding the conversion table from meters to several other units.
      *
-     * @var array
+     * @var array<string, int|float>
      */
-    private $conversion = [
-        'cm' => '100', // centimeters
-        'in' => '39.3700787', // inches
-        'ft' => '3.2808399', // feet
-        'm' => '1', // meters
-        'km' => '0.001', // kilometers
-        'mi' => '0.000621371192', // miles
+    private array $conversion = [
+        'cm' => 100, // centimeters
+        'in' => 39.3700787, // inches
+        'ft' => 3.2808399, // feet
+        'm' => 1, // meters
+        'km' => 0.001, // kilometers
+        'mi' => 0.000621371192, // miles
     ];
 
     /**
      * Method that returns the distance between two GPS locations in the preferred unit according to the set formula.
-     *
-     * @param float $latitudeA The latitude for point A.
-     * @param float $longitudeA The longitude for point A.
-     * @param float $latitudeB The latitude for point B.
-     * @param float $longitudeB The longitude for point B.
-     *
-     * @uses betweenVincenty
-     * @uses betweenHaversine
-     * @throws Exception
-     * @return float
      */
-    public function between($latitudeA, $longitudeA, $latitudeB, $longitudeB)
+    public function between(float $latitudeA, float $longitudeA, float $latitudeB, float $longitudeB): float
     {
-        if (!floatval($latitudeA) || !floatval($longitudeA) || !floatval($latitudeB) || !floatval($longitudeB)) {
-            throw new Exception('One or more of the parsed variables are not valid floats.');
-        }
-
-        $distanceInMeters = call_user_func_array([$this, 'between' . ucfirst($this->getFormula())],
-            [$latitudeA, $longitudeA, $latitudeB, $longitudeB]);
+        $distanceInMeters = match ($this->getFormula()) {
+            'vincenty' => $this->betweenVincenty($latitudeA, $longitudeA, $latitudeB, $longitudeB),
+            'haversine' => $this->betweenHaversine($latitudeA, $longitudeA, $latitudeB, $longitudeB),
+            default => throw new RuntimeException('Invalid formula'),
+        };
 
         return $this->convert($distanceInMeters);
     }
 
     /**
      * Method that returns the distance between two GPS locations in meters according to the Vincenty formula.
-     *
-     * @param float $latitudeA The latitude for point A.
-     * @param float $longitudeA The longitude for point A.
-     * @param float $latitudeB The latitude for point B.
-     * @param float $longitudeB The longitude for point B.
-     *
-     * @return float
      */
-    private function betweenVincenty($latitudeA, $longitudeA, $latitudeB, $longitudeB)
+    private function betweenVincenty(float $latitudeA, float $longitudeA, float $latitudeB, float $longitudeB): float
     {
         $latitudeA = deg2rad($latitudeA);
         $longitudeA = deg2rad($longitudeA);
         $latitudeB = deg2rad($latitudeB);
         $longitudeB = deg2rad($longitudeB);
         $longDelta = $longitudeB - $longitudeA;
-        $a = pow(cos($latitudeB) * sin($longDelta),
-                2) + pow(cos($latitudeA) * sin($latitudeB) - sin($latitudeA) * cos($latitudeB) * cos($longDelta), 2);
+        $a = ((cos($latitudeB) * sin($longDelta)) ** 2) + ((cos($latitudeA) * sin($latitudeB) - sin($latitudeA) * cos($latitudeB) * cos($longDelta)) ** 2);
         $b = sin($latitudeA) * sin($latitudeB) + cos($latitudeA) * cos($latitudeB) * cos($longDelta);
         $angle = atan2(sqrt($a), $b);
 
@@ -94,15 +68,8 @@ private function betweenVincenty($latitudeA, $longitudeA, $latitudeB, $longitude
 
     /**
      * Method that returns the distance between two GPS locations in meters according to the Haversine formula.
-     *
-     * @param float $latitudeA The latitude for point A.
-     * @param float $longitudeA The longitude for point A.
-     * @param float $latitudeB The latitude for point B.
-     * @param float $longitudeB The longitude for point B.
-     *
-     * @return float
      */
-    private function betweenHaversine($latitudeA, $longitudeA, $latitudeB, $longitudeB)
+    private function betweenHaversine(float $latitudeA, float $longitudeA, float $latitudeB, float $longitudeB): float
     {
         $latitudeA = deg2rad($latitudeA);
         $longitudeA = deg2rad($longitudeA);
@@ -110,26 +77,20 @@ private function betweenHaversine($latitudeA, $longitudeA, $latitudeB, $longitud
         $longitudeB = deg2rad($longitudeB);
         $latDelta = $latitudeB - $latitudeA;
         $longDelta = $longitudeB - $longitudeA;
-        $angle = 2 * asin(sqrt(pow(sin($latDelta / 2), 2) + cos($latitudeA) * cos($latitudeB) * pow(sin($longDelta / 2), 2)));
+        $angle = 2 * asin(sqrt((sin($latDelta / 2) ** 2) + cos($latitudeA) * cos($latitudeB) * (sin($longDelta / 2) ** 2)));
 
         return floor($angle * 6371000);
     }
 
-    /**
-     * @param $distance
-     * @return mixed
-     */
-    private function convert($distance)
+    private function convert(float $distance): float
     {
-        return $distance * $this->getConversion()[$this->getUnit()];
+        return $distance * $this->conversion[$this->getUnit()];
     }
 
     /**
      * Returns the currently set formula used for distance calculation.
-     *
-     * @return string
      */
-    public function getFormula()
+    public function getFormula(): string
     {
         return $this->formula;
     }
@@ -137,14 +98,12 @@ public function getFormula()
     /**
      * Sets the formula to be used for distance calculation.
      *
-     * @param string $formula
-     *
-     * @throws Exception
+     * @throws RuntimeException
      */
-    public function setFormula($formula)
+    public function setFormula(string $formula): void
     {
-        if (!in_array($formula, ['vincenty', 'haversine'])) {
-            throw new Exception('You have tried to set an invalid distance formula.');
+        if (!in_array($formula, ['vincenty', 'haversine'], true)) {
+            throw new RuntimeException('You have tried to set an invalid distance formula.');
         }
 
         $this->formula = $formula;
@@ -152,10 +111,8 @@ public function setFormula($formula)
 
     /**
      * Returns the currently set unit used when returning the distance between two coordinates.
-     *
-     * @return string
      */
-    public function getUnit()
+    public function getUnit(): string
     {
         return $this->unit;
     }
@@ -163,27 +120,14 @@ public function getUnit()
     /**
      * Sets the unit to be used when returning the distance between two coordinates.
      *
-     * @param string $unit
-     *
-     * @throws Exception
+     * @throws RuntimeException
      */
-    public function setUnit($unit)
+    public function setUnit(string $unit): void
     {
-        if (!in_array($unit, array_keys($this->getConversion()))) {
-            throw new Exception('You have tried to set an invalid distance unit.');
+        if (!array_key_exists($unit, $this->conversion)) {
+            throw new RuntimeException('You have tried to set an invalid distance unit.');
         }
 
         $this->unit = $unit;
     }
-
-    /**
-     * Gets the conversion table between different units.
-     *
-     * @return array
-     */
-    public function getConversion()
-    {
-        return $this->conversion;
-    }
-
-}
\ No newline at end of file
+}
diff --git a/tests/DistanceTest.php b/tests/DistanceTest.php
index 5ac711c..2b599ef 100644
--- a/tests/DistanceTest.php
+++ b/tests/DistanceTest.php
@@ -2,9 +2,12 @@
 
 declare(strict_types=1);
 
+namespace Tests\LucDeBrouwer\Distance;
+
 use LucDeBrouwer\Distance\Distance;
 use PHPUnit\Framework\Attributes\Test;
 use PHPUnit\Framework\TestCase;
+use RuntimeException;
 
 class DistanceTest extends TestCase
 {
@@ -20,7 +23,7 @@ public function canSetUnit(): void
     #[Test]
     public function willThrowExceptionInCaseWeSetAnInvalidUnit(): void
     {
-        $this->expectException(Exception::class);
+        $this->expectException(RuntimeException::class);
         $this->expectExceptionMessage('You have tried to set an invalid distance unit.');
 
         $distance = new Distance();
@@ -40,7 +43,7 @@ public function canSetFormula(): void
     #[Test]
     public function willThrowExceptionInCaseWeSetAnInvalidFormula(): void
     {
-        $this->expectException(Exception::class);
+        $this->expectException(RuntimeException::class);
         $this->expectExceptionMessage('You have tried to set an invalid distance formula.');
 
         $distance = new Distance();
@@ -48,17 +51,6 @@ public function willThrowExceptionInCaseWeSetAnInvalidFormula(): void
         $distance->setFormula('Leonardo');
     }
 
-    #[Test]
-    public function willThrowAnExceptionInCaseWeProvideInvalidParameters(): void
-    {
-        $this->expectException(Exception::class);
-        $this->expectExceptionMessage('One or more of the parsed variables are not valid floats.');
-
-        $distance = new Distance();
-
-        $distance->between('1', 1, 'not a float', 'invalid');
-    }
-
     #[Test]
     public function canConvertDistanceUsingVincentyFormula(): void
     {
@@ -118,4 +110,4 @@ public function canConvertDistanceUsingHaversineFormula(): void
 
         $this->assertSame(439527.5586068, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
     }
-}
\ No newline at end of file
+}

From 70e76011cb2eda70c21107200228891d0a721d0a Mon Sep 17 00:00:00 2001
From: Luc De Brouwer <info@lucdebrouwer.nl>
Date: Sun, 22 Feb 2026 15:32:48 +0000
Subject: [PATCH 03/11] Use a string-backed enumeration class for formulas.

---
 src/Distance.php       | 15 +++++----------
 src/Formula.php        | 11 +++++++++++
 tests/DistanceTest.php | 20 +++++---------------
 3 files changed, 21 insertions(+), 25 deletions(-)
 create mode 100644 src/Formula.php

diff --git a/src/Distance.php b/src/Distance.php
index 3fe030a..15f3e24 100644
--- a/src/Distance.php
+++ b/src/Distance.php
@@ -14,7 +14,7 @@ class Distance
     /**
      * The formula used for distance calculation.
      */
-    private string $formula = 'vincenty';
+    private Formula $formula = Formula::VINCENTY;
 
     /**
      * The unit used to return the distance in. The supported units are shown in the conversion table below.
@@ -41,9 +41,8 @@ class Distance
     public function between(float $latitudeA, float $longitudeA, float $latitudeB, float $longitudeB): float
     {
         $distanceInMeters = match ($this->getFormula()) {
-            'vincenty' => $this->betweenVincenty($latitudeA, $longitudeA, $latitudeB, $longitudeB),
-            'haversine' => $this->betweenHaversine($latitudeA, $longitudeA, $latitudeB, $longitudeB),
-            default => throw new RuntimeException('Invalid formula'),
+            Formula::VINCENTY => $this->betweenVincenty($latitudeA, $longitudeA, $latitudeB, $longitudeB),
+            Formula::HAVERSINE => $this->betweenHaversine($latitudeA, $longitudeA, $latitudeB, $longitudeB),
         };
 
         return $this->convert($distanceInMeters);
@@ -90,7 +89,7 @@ private function convert(float $distance): float
     /**
      * Returns the currently set formula used for distance calculation.
      */
-    public function getFormula(): string
+    public function getFormula(): Formula
     {
         return $this->formula;
     }
@@ -100,12 +99,8 @@ public function getFormula(): string
      *
      * @throws RuntimeException
      */
-    public function setFormula(string $formula): void
+    public function setFormula(Formula $formula): void
     {
-        if (!in_array($formula, ['vincenty', 'haversine'], true)) {
-            throw new RuntimeException('You have tried to set an invalid distance formula.');
-        }
-
         $this->formula = $formula;
     }
 
diff --git a/src/Formula.php b/src/Formula.php
new file mode 100644
index 0000000..62425b7
--- /dev/null
+++ b/src/Formula.php
@@ -0,0 +1,11 @@
+<?php
+
+declare(strict_types=1);
+
+namespace LucDeBrouwer\Distance;
+
+enum Formula: string
+{
+    case VINCENTY = 'vincenty';
+    case HAVERSINE = 'haversine';
+}
diff --git a/tests/DistanceTest.php b/tests/DistanceTest.php
index 2b599ef..661e110 100644
--- a/tests/DistanceTest.php
+++ b/tests/DistanceTest.php
@@ -5,6 +5,7 @@
 namespace Tests\LucDeBrouwer\Distance;
 
 use LucDeBrouwer\Distance\Distance;
+use LucDeBrouwer\Distance\Formula;
 use PHPUnit\Framework\Attributes\Test;
 use PHPUnit\Framework\TestCase;
 use RuntimeException;
@@ -35,20 +36,9 @@ public function willThrowExceptionInCaseWeSetAnInvalidUnit(): void
     public function canSetFormula(): void
     {
         $distance = new Distance();
-        $distance->setFormula('vincenty');
+        $distance->setFormula(Formula::VINCENTY);
 
-        $this->assertSame('vincenty', $distance->getFormula());
-    }
-
-    #[Test]
-    public function willThrowExceptionInCaseWeSetAnInvalidFormula(): void
-    {
-        $this->expectException(RuntimeException::class);
-        $this->expectExceptionMessage('You have tried to set an invalid distance formula.');
-
-        $distance = new Distance();
-
-        $distance->setFormula('Leonardo');
+        $this->assertSame(Formula::VINCENTY, $distance->getFormula());
     }
 
     #[Test]
@@ -56,7 +46,7 @@ public function canConvertDistanceUsingVincentyFormula(): void
     {
         $distance = new Distance();
         $distance->setUnit('m');
-        $distance->setFormula('vincenty');
+        $distance->setFormula(Formula::VINCENTY);
 
         $this->assertSame(11164.0, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
 
@@ -86,7 +76,7 @@ public function canConvertDistanceUsingHaversineFormula(): void
     {
         $distance = new Distance();
         $distance->setUnit('m');
-        $distance->setFormula('haversine');
+        $distance->setFormula(Formula::HAVERSINE);
 
         $this->assertSame(11164.0, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
 

From 66fc006fe8bc026de78d7742c314fdda1ec3d1ce Mon Sep 17 00:00:00 2001
From: Luc De Brouwer <info@lucdebrouwer.nl>
Date: Sun, 22 Feb 2026 15:49:02 +0000
Subject: [PATCH 04/11] Use a string-backed enumeration class for units.

---
 src/Distance.php       | 32 ++++----------------------------
 src/Unit.php           | 27 +++++++++++++++++++++++++++
 tests/DistanceTest.php | 41 +++++++++++++++--------------------------
 3 files changed, 46 insertions(+), 54 deletions(-)
 create mode 100644 src/Unit.php

diff --git a/src/Distance.php b/src/Distance.php
index 15f3e24..cfbc658 100644
--- a/src/Distance.php
+++ b/src/Distance.php
@@ -4,8 +4,6 @@
 
 namespace LucDeBrouwer\Distance;
 
-use RuntimeException;
-
 /**
  * Distance helps you calculate the distance between GPS coordinates, in vanilla PHP. Pure and simple.
  */
@@ -19,21 +17,7 @@ class Distance
     /**
      * The unit used to return the distance in. The supported units are shown in the conversion table below.
      */
-    private string $unit = 'km';
-
-    /**
-     * An array holding the conversion table from meters to several other units.
-     *
-     * @var array<string, int|float>
-     */
-    private array $conversion = [
-        'cm' => 100, // centimeters
-        'in' => 39.3700787, // inches
-        'ft' => 3.2808399, // feet
-        'm' => 1, // meters
-        'km' => 0.001, // kilometers
-        'mi' => 0.000621371192, // miles
-    ];
+    private Unit $unit = Unit::KILOMETRES;
 
     /**
      * Method that returns the distance between two GPS locations in the preferred unit according to the set formula.
@@ -83,7 +67,7 @@ private function betweenHaversine(float $latitudeA, float $longitudeA, float $la
 
     private function convert(float $distance): float
     {
-        return $distance * $this->conversion[$this->getUnit()];
+        return $distance * $this->unit->multiplierFromMetres();
     }
 
     /**
@@ -96,8 +80,6 @@ public function getFormula(): Formula
 
     /**
      * Sets the formula to be used for distance calculation.
-     *
-     * @throws RuntimeException
      */
     public function setFormula(Formula $formula): void
     {
@@ -107,22 +89,16 @@ public function setFormula(Formula $formula): void
     /**
      * Returns the currently set unit used when returning the distance between two coordinates.
      */
-    public function getUnit(): string
+    public function getUnit(): Unit
     {
         return $this->unit;
     }
 
     /**
      * Sets the unit to be used when returning the distance between two coordinates.
-     *
-     * @throws RuntimeException
      */
-    public function setUnit(string $unit): void
+    public function setUnit(Unit $unit): void
     {
-        if (!array_key_exists($unit, $this->conversion)) {
-            throw new RuntimeException('You have tried to set an invalid distance unit.');
-        }
-
         $this->unit = $unit;
     }
 }
diff --git a/src/Unit.php b/src/Unit.php
new file mode 100644
index 0000000..58effb7
--- /dev/null
+++ b/src/Unit.php
@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+namespace LucDeBrouwer\Distance;
+
+enum Unit: string
+{
+    case CENTIMETRES = 'cm';
+    case INCHES = 'in';
+    case FEET = 'ft';
+    case METRES = 'm';
+    case KILOMETRES = 'km';
+    case MILES = 'mi';
+
+    public function multiplierFromMetres(): int|float
+    {
+        return match ($this) {
+            self::CENTIMETRES => 100,
+            self::INCHES => 39.3700787,
+            self::FEET => 3.2808399,
+            self::METRES => 1,
+            self::KILOMETRES => 0.001,
+            self::MILES => 0.000621371192,
+        };
+    }
+}
diff --git a/tests/DistanceTest.php b/tests/DistanceTest.php
index 661e110..7d99ab3 100644
--- a/tests/DistanceTest.php
+++ b/tests/DistanceTest.php
@@ -6,9 +6,9 @@
 
 use LucDeBrouwer\Distance\Distance;
 use LucDeBrouwer\Distance\Formula;
+use LucDeBrouwer\Distance\Unit;
 use PHPUnit\Framework\Attributes\Test;
 use PHPUnit\Framework\TestCase;
-use RuntimeException;
 
 class DistanceTest extends TestCase
 {
@@ -16,20 +16,9 @@ class DistanceTest extends TestCase
     public function canSetUnit(): void
     {
         $distance = new Distance();
-        $distance->setUnit('mi');
+        $distance->setUnit(Unit::MILES);
 
-        $this->assertSame('mi', $distance->getUnit());
-    }
-
-    #[Test]
-    public function willThrowExceptionInCaseWeSetAnInvalidUnit(): void
-    {
-        $this->expectException(RuntimeException::class);
-        $this->expectExceptionMessage('You have tried to set an invalid distance unit.');
-
-        $distance = new Distance();
-
-        $distance->setUnit('mm');
+        $this->assertSame(Unit::MILES, $distance->getUnit());
     }
 
     #[Test]
@@ -45,28 +34,28 @@ public function canSetFormula(): void
     public function canConvertDistanceUsingVincentyFormula(): void
     {
         $distance = new Distance();
-        $distance->setUnit('m');
+        $distance->setUnit(Unit::METRES);
         $distance->setFormula(Formula::VINCENTY);
 
         $this->assertSame(11164.0, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
 
-        $distance->setUnit('km');
+        $distance->setUnit(Unit::KILOMETRES);
 
         $this->assertSame(11.164, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
 
-        $distance->setUnit('mi');
+        $distance->setUnit(Unit::MILES);
 
         $this->assertSame(6.936987987488, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
 
-        $distance->setUnit('cm');
+        $distance->setUnit(Unit::CENTIMETRES);
 
         $this->assertSame(1116400.0, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
 
-        $distance->setUnit('ft');
+        $distance->setUnit(Unit::FEET);
 
         $this->assertSame(36627.2966436, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
 
-        $distance->setUnit('in');
+        $distance->setUnit(Unit::INCHES);
 
         $this->assertSame(439527.5586068, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
     }
@@ -75,28 +64,28 @@ public function canConvertDistanceUsingVincentyFormula(): void
     public function canConvertDistanceUsingHaversineFormula(): void
     {
         $distance = new Distance();
-        $distance->setUnit('m');
+        $distance->setUnit(Unit::METRES);
         $distance->setFormula(Formula::HAVERSINE);
 
         $this->assertSame(11164.0, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
 
-        $distance->setUnit('km');
+        $distance->setUnit(Unit::KILOMETRES);
 
         $this->assertSame(11.164, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
 
-        $distance->setUnit('mi');
+        $distance->setUnit(Unit::MILES);
 
         $this->assertSame(6.936987987488, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
 
-        $distance->setUnit('cm');
+        $distance->setUnit(Unit::CENTIMETRES);
 
         $this->assertSame(1116400.0, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
 
-        $distance->setUnit('ft');
+        $distance->setUnit(Unit::FEET);
 
         $this->assertSame(36627.2966436, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
 
-        $distance->setUnit('in');
+        $distance->setUnit(Unit::INCHES);
 
         $this->assertSame(439527.5586068, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
     }

From d09bd89e2ab02ac6659c5183db70c4cb2bbcb049 Mon Sep 17 00:00:00 2001
From: Luc De Brouwer <info@lucdebrouwer.nl>
Date: Sun, 22 Feb 2026 16:08:22 +0000
Subject: [PATCH 05/11] Make setters fluent, clean up tests.

---
 src/Distance.php       | 16 ++++++----
 tests/DistanceTest.php | 72 ++++++++++++++----------------------------
 2 files changed, 34 insertions(+), 54 deletions(-)

diff --git a/src/Distance.php b/src/Distance.php
index cfbc658..80960fb 100644
--- a/src/Distance.php
+++ b/src/Distance.php
@@ -15,12 +15,12 @@ class Distance
     private Formula $formula = Formula::VINCENTY;
 
     /**
-     * The unit used to return the distance in. The supported units are shown in the conversion table below.
+     * The unit used to return the distance in.
      */
     private Unit $unit = Unit::KILOMETRES;
 
     /**
-     * Method that returns the distance between two GPS locations in the preferred unit according to the set formula.
+     * Returns the distance between two GPS locations in the preferred unit according to the set formula.
      */
     public function between(float $latitudeA, float $longitudeA, float $latitudeB, float $longitudeB): float
     {
@@ -33,7 +33,7 @@ public function between(float $latitudeA, float $longitudeA, float $latitudeB, f
     }
 
     /**
-     * Method that returns the distance between two GPS locations in meters according to the Vincenty formula.
+     * Returns the distance between two GPS locations in meters according to the Vincenty formula.
      */
     private function betweenVincenty(float $latitudeA, float $longitudeA, float $latitudeB, float $longitudeB): float
     {
@@ -50,7 +50,7 @@ private function betweenVincenty(float $latitudeA, float $longitudeA, float $lat
     }
 
     /**
-     * Method that returns the distance between two GPS locations in meters according to the Haversine formula.
+     * Returns the distance between two GPS locations in meters according to the Haversine formula.
      */
     private function betweenHaversine(float $latitudeA, float $longitudeA, float $latitudeB, float $longitudeB): float
     {
@@ -81,9 +81,11 @@ public function getFormula(): Formula
     /**
      * Sets the formula to be used for distance calculation.
      */
-    public function setFormula(Formula $formula): void
+    public function setFormula(Formula $formula): self
     {
         $this->formula = $formula;
+
+        return $this;
     }
 
     /**
@@ -97,8 +99,10 @@ public function getUnit(): Unit
     /**
      * Sets the unit to be used when returning the distance between two coordinates.
      */
-    public function setUnit(Unit $unit): void
+    public function setUnit(Unit $unit): self
     {
         $this->unit = $unit;
+
+        return $this;
     }
 }
diff --git a/tests/DistanceTest.php b/tests/DistanceTest.php
index 7d99ab3..5583012 100644
--- a/tests/DistanceTest.php
+++ b/tests/DistanceTest.php
@@ -8,17 +8,23 @@
 use LucDeBrouwer\Distance\Formula;
 use LucDeBrouwer\Distance\Unit;
 use PHPUnit\Framework\Attributes\Test;
+use PHPUnit\Framework\Attributes\TestWith;
 use PHPUnit\Framework\TestCase;
 
 class DistanceTest extends TestCase
 {
+    private const float LATITUDE_A = 37.331741;
+    private const float LONGITUDE_A = -122.030333;
+    private const float LATITUDE_B = 37.422546;
+    private const float LONGITUDE_B = -122.084250;
+
     #[Test]
     public function canSetUnit(): void
     {
         $distance = new Distance();
         $distance->setUnit(Unit::MILES);
 
-        $this->assertSame(Unit::MILES, $distance->getUnit());
+        self::assertSame(Unit::MILES, $distance->getUnit());
     }
 
     #[Test]
@@ -27,66 +33,36 @@ public function canSetFormula(): void
         $distance = new Distance();
         $distance->setFormula(Formula::VINCENTY);
 
-        $this->assertSame(Formula::VINCENTY, $distance->getFormula());
+        self::assertSame(Formula::VINCENTY, $distance->getFormula());
     }
 
     #[Test]
-    public function canConvertDistanceUsingVincentyFormula(): void
+    #[TestWith([Unit::METRES, 11164.0])]
+    #[TestWith([Unit::KILOMETRES, 11.164])]
+    #[TestWith([Unit::MILES, 6.936987987488])]
+    #[TestWith([Unit::CENTIMETRES, 1116400.0])]
+    #[TestWith([Unit::FEET, 36627.2966436])]
+    #[TestWith([Unit::INCHES, 439527.5586068])]
+    public function canConvertDistanceUsingVincentyFormula(Unit $unit, float $expected): void
     {
         $distance = new Distance();
-        $distance->setUnit(Unit::METRES);
         $distance->setFormula(Formula::VINCENTY);
 
-        $this->assertSame(11164.0, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
-
-        $distance->setUnit(Unit::KILOMETRES);
-
-        $this->assertSame(11.164, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
-
-        $distance->setUnit(Unit::MILES);
-
-        $this->assertSame(6.936987987488, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
-
-        $distance->setUnit(Unit::CENTIMETRES);
-
-        $this->assertSame(1116400.0, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
-
-        $distance->setUnit(Unit::FEET);
-
-        $this->assertSame(36627.2966436, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
-
-        $distance->setUnit(Unit::INCHES);
-
-        $this->assertSame(439527.5586068, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
+        self::assertSame($expected, $distance->setUnit($unit)->between(self::LATITUDE_A, self::LONGITUDE_A, self::LATITUDE_B, self::LONGITUDE_B));
     }
 
     #[Test]
-    public function canConvertDistanceUsingHaversineFormula(): void
+    #[TestWith([Unit::METRES, 11164.0])]
+    #[TestWith([Unit::KILOMETRES, 11.164])]
+    #[TestWith([Unit::MILES, 6.936987987488])]
+    #[TestWith([Unit::CENTIMETRES, 1116400.0])]
+    #[TestWith([Unit::FEET, 36627.2966436])]
+    #[TestWith([Unit::INCHES, 439527.5586068])]
+    public function canConvertDistanceUsingHaversineFormula(Unit $unit, float $expected): void
     {
         $distance = new Distance();
-        $distance->setUnit(Unit::METRES);
         $distance->setFormula(Formula::HAVERSINE);
 
-        $this->assertSame(11164.0, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
-
-        $distance->setUnit(Unit::KILOMETRES);
-
-        $this->assertSame(11.164, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
-
-        $distance->setUnit(Unit::MILES);
-
-        $this->assertSame(6.936987987488, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
-
-        $distance->setUnit(Unit::CENTIMETRES);
-
-        $this->assertSame(1116400.0, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
-
-        $distance->setUnit(Unit::FEET);
-
-        $this->assertSame(36627.2966436, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
-
-        $distance->setUnit(Unit::INCHES);
-
-        $this->assertSame(439527.5586068, $distance->between(37.331741, -122.030333, 37.422546, -122.084250));
+        self::assertSame($expected, $distance->setUnit($unit)->between(self::LATITUDE_A, self::LONGITUDE_A, self::LATITUDE_B, self::LONGITUDE_B));
     }
 }

From 84873033d3f87a33c6c550f067e869f804b9f419 Mon Sep 17 00:00:00 2001
From: Luc De Brouwer <info@lucdebrouwer.nl>
Date: Sun, 22 Feb 2026 18:44:45 +0000
Subject: [PATCH 06/11] GitHub workflows setup.

---
 .github/workflows/php_84.yml | 39 ++++++++++++++++++++++++++++++++++++
 .github/workflows/php_85.yml | 39 ++++++++++++++++++++++++++++++++++++
 .gitignore                   |  1 -
 phpstan.neon                 |  1 -
 4 files changed, 78 insertions(+), 2 deletions(-)
 create mode 100644 .github/workflows/php_84.yml
 create mode 100644 .github/workflows/php_85.yml

diff --git a/.github/workflows/php_84.yml b/.github/workflows/php_84.yml
new file mode 100644
index 0000000..aa7d89b
--- /dev/null
+++ b/.github/workflows/php_84.yml
@@ -0,0 +1,39 @@
+name: PHP 8.4
+on: push
+
+jobs:
+  build:
+    name: Static analysis, unit tests, and linting
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Setup PHP 8.4
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: '8.4'
+          tools: composer
+
+      - name: Cache Composer dependencies
+        uses: actions/cache@v5
+        with:
+          path: ./vendor
+          key: composer-${{ runner.os }}-8.4
+
+      - name: Install dependencies
+        run: |
+          composer install
+
+      - name: Run PHPStan
+        run: |
+          ./vendor/bin/phpstan
+
+      - name: PHP Code Sniffer
+        run: |
+          ./vendor/bin/phpcs
+
+      - name: Run PHPUnit
+        run: |
+          ./vendor/bin/phpunit
\ No newline at end of file
diff --git a/.github/workflows/php_85.yml b/.github/workflows/php_85.yml
new file mode 100644
index 0000000..b44a2d1
--- /dev/null
+++ b/.github/workflows/php_85.yml
@@ -0,0 +1,39 @@
+name: PHP 8.5
+on: push
+
+jobs:
+  build:
+    name: Static analysis, unit tests, and linting
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Setup PHP 8.5
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: '8.5'
+          tools: composer
+
+      - name: Cache Composer dependencies
+        uses: actions/cache@v5
+        with:
+          path: ./vendor
+          key: composer-${{ runner.os }}-8.5
+
+      - name: Install dependencies
+        run: |
+          composer install
+
+      - name: Run PHPStan
+        run: |
+          ./vendor/bin/phpstan
+
+      - name: PHP Code Sniffer
+        run: |
+          ./vendor/bin/phpcs
+
+      - name: Run PHPUnit
+        run: |
+          ./vendor/bin/phpunit
\ No newline at end of file
diff --git a/.gitignore b/.gitignore
index edede23..0f0f75e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,6 +2,5 @@
 composer.phar
 composer.lock
 vendor/
-storage/
 .phpunit.cache
 .phpunit.result.cache
\ No newline at end of file
diff --git a/phpstan.neon b/phpstan.neon
index a29f3a0..fa81b49 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -3,7 +3,6 @@ parameters:
 	paths:
 		- src
 		- tests
-	tmpDir: /var/www/html/storage/phpstan-cache
 	reportUnmatchedIgnoredErrors: true
 
 includes:

From 689b8b674727735aa9794a3006cc171ebfd63c71 Mon Sep 17 00:00:00 2001
From: Luc De Brouwer <info@lucdebrouwer.nl>
Date: Mon, 23 Feb 2026 19:21:51 +0000
Subject: [PATCH 07/11] Combine workflows, generate code coverage and upload it
 to Codecov.

---
 .github/workflows/php_84.yml | 39 -----------------
 .github/workflows/php_85.yml | 39 -----------------
 .github/workflows/tests.yml  | 83 ++++++++++++++++++++++++++++++++++++
 README.md                    |  2 +-
 4 files changed, 84 insertions(+), 79 deletions(-)
 delete mode 100644 .github/workflows/php_84.yml
 delete mode 100644 .github/workflows/php_85.yml
 create mode 100644 .github/workflows/tests.yml

diff --git a/.github/workflows/php_84.yml b/.github/workflows/php_84.yml
deleted file mode 100644
index aa7d89b..0000000
--- a/.github/workflows/php_84.yml
+++ /dev/null
@@ -1,39 +0,0 @@
-name: PHP 8.4
-on: push
-
-jobs:
-  build:
-    name: Static analysis, unit tests, and linting
-    runs-on: ubuntu-latest
-
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v6
-
-      - name: Setup PHP 8.4
-        uses: shivammathur/setup-php@v2
-        with:
-          php-version: '8.4'
-          tools: composer
-
-      - name: Cache Composer dependencies
-        uses: actions/cache@v5
-        with:
-          path: ./vendor
-          key: composer-${{ runner.os }}-8.4
-
-      - name: Install dependencies
-        run: |
-          composer install
-
-      - name: Run PHPStan
-        run: |
-          ./vendor/bin/phpstan
-
-      - name: PHP Code Sniffer
-        run: |
-          ./vendor/bin/phpcs
-
-      - name: Run PHPUnit
-        run: |
-          ./vendor/bin/phpunit
\ No newline at end of file
diff --git a/.github/workflows/php_85.yml b/.github/workflows/php_85.yml
deleted file mode 100644
index b44a2d1..0000000
--- a/.github/workflows/php_85.yml
+++ /dev/null
@@ -1,39 +0,0 @@
-name: PHP 8.5
-on: push
-
-jobs:
-  build:
-    name: Static analysis, unit tests, and linting
-    runs-on: ubuntu-latest
-
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v6
-
-      - name: Setup PHP 8.5
-        uses: shivammathur/setup-php@v2
-        with:
-          php-version: '8.5'
-          tools: composer
-
-      - name: Cache Composer dependencies
-        uses: actions/cache@v5
-        with:
-          path: ./vendor
-          key: composer-${{ runner.os }}-8.5
-
-      - name: Install dependencies
-        run: |
-          composer install
-
-      - name: Run PHPStan
-        run: |
-          ./vendor/bin/phpstan
-
-      - name: PHP Code Sniffer
-        run: |
-          ./vendor/bin/phpcs
-
-      - name: Run PHPUnit
-        run: |
-          ./vendor/bin/phpunit
\ No newline at end of file
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
new file mode 100644
index 0000000..73faf98
--- /dev/null
+++ b/.github/workflows/tests.yml
@@ -0,0 +1,83 @@
+name: Tests
+on: push
+
+jobs:
+  build-84:
+    name: Static analysis, unit tests, and linting on PHP 8.4
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Setup PHP 8.4
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: '8.4'
+          tools: composer
+
+      - name: Cache Composer dependencies
+        uses: actions/cache@v5
+        with:
+          path: ./vendor
+          key: composer-${{ runner.os }}-8.4
+
+      - name: Install dependencies
+        run: |
+          composer install
+
+      - name: Run PHPStan
+        run: |
+          ./vendor/bin/phpstan
+
+      - name: PHP Code Sniffer
+        run: |
+          ./vendor/bin/phpcs
+
+      - name: Run PHPUnit
+        run: |
+          ./vendor/bin/phpunit
+
+  build-85:
+    name: Static analysis, unit tests, and linting on PHP 8.5
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Setup PHP 8.5
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: '8.5'
+          tools: composer
+          coverage: pcov
+
+      - name: Cache Composer dependencies
+        uses: actions/cache@v5
+        with:
+          path: ./vendor
+          key: composer-${{ runner.os }}-8.5
+
+      - name: Install dependencies
+        run: |
+          composer install
+
+      - name: Run PHPStan
+        run: |
+          ./vendor/bin/phpstan
+
+      - name: PHP Code Sniffer
+        run: |
+          ./vendor/bin/phpcs
+
+      - name: Run PHPUnit
+        run: |
+          ./vendor/bin/phpunit --coverage-clover ./coverage.xml
+
+      - name: Upload to Codecov
+        uses: codecov/codecov-action@v5
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          files: ./coverage.xml
+          verbose: true
\ No newline at end of file
diff --git a/README.md b/README.md
index a3877bf..3517722 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 # Distance
-[![Build Status](https://travis-ci.org/ldebrouwer/distance.svg)](https://travis-ci.org/ldebrouwer/distance)
+[![Tests](https://github.com/ldebrouwer/distance/actions/workflows/tests.yml/badge.svg)](https://github.com/ldebrouwer/distance/actions/workflows/tests.yml)
 [![Latest Stable Version](https://poser.pugx.org/ldebrouwer/distance/v/stable)](https://packagist.org/packages/ldebrouwer/distance)
 [![Total Downloads](https://poser.pugx.org/ldebrouwer/distance/downloads)](https://packagist.org/packages/ldebrouwer/distance)
 [![Latest Unstable Version](https://poser.pugx.org/ldebrouwer/distance/v/unstable)](https://packagist.org/packages/ldebrouwer/distance)

From 3007f1cf5c1c4b77ca6424c901f87093df591eb0 Mon Sep 17 00:00:00 2001
From: Luc De Brouwer <info@lucdebrouwer.nl>
Date: Mon, 23 Feb 2026 19:48:24 +0000
Subject: [PATCH 08/11] Update namespace for consistent naming.

---
 composer.json          | 7 +++----
 src/Distance.php       | 2 +-
 src/Formula.php        | 2 +-
 src/Unit.php           | 2 +-
 tests/DistanceTest.php | 8 ++++----
 5 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/composer.json b/composer.json
index bbe0326..13af2b5 100644
--- a/composer.json
+++ b/composer.json
@@ -17,8 +17,7 @@
     {
       "name": "Luc De Brouwer",
       "email": "info@lucdebrouwer.nl",
-      "homepage": "http://www.lucdebrouwer.nl",
-      "role": "Developer"
+      "homepage": "http://www.lucdebrouwer.nl"
     }
   ],
   "require": {
@@ -40,12 +39,12 @@
   },
   "autoload": {
     "psr-4": {
-      "LucDeBrouwer\\Distance\\": "src/"
+      "ldebrouwer\\Distance\\": "src/"
     }
   },
   "autoload-dev": {
     "psr-4": {
-      "Tests\\LucDeBrouwer\\Distance\\": "tests/"
+      "Tests\\ldebrouwer\\Distance\\": "tests/"
     }
   },
   "config": {
diff --git a/src/Distance.php b/src/Distance.php
index 80960fb..b12b10a 100644
--- a/src/Distance.php
+++ b/src/Distance.php
@@ -2,7 +2,7 @@
 
 declare(strict_types=1);
 
-namespace LucDeBrouwer\Distance;
+namespace ldebrouwer\Distance;
 
 /**
  * Distance helps you calculate the distance between GPS coordinates, in vanilla PHP. Pure and simple.
diff --git a/src/Formula.php b/src/Formula.php
index 62425b7..156b079 100644
--- a/src/Formula.php
+++ b/src/Formula.php
@@ -2,7 +2,7 @@
 
 declare(strict_types=1);
 
-namespace LucDeBrouwer\Distance;
+namespace ldebrouwer\Distance;
 
 enum Formula: string
 {
diff --git a/src/Unit.php b/src/Unit.php
index 58effb7..45884d2 100644
--- a/src/Unit.php
+++ b/src/Unit.php
@@ -2,7 +2,7 @@
 
 declare(strict_types=1);
 
-namespace LucDeBrouwer\Distance;
+namespace ldebrouwer\Distance;
 
 enum Unit: string
 {
diff --git a/tests/DistanceTest.php b/tests/DistanceTest.php
index 5583012..f4ffc5c 100644
--- a/tests/DistanceTest.php
+++ b/tests/DistanceTest.php
@@ -2,11 +2,11 @@
 
 declare(strict_types=1);
 
-namespace Tests\LucDeBrouwer\Distance;
+namespace Tests\ldebrouwer\Distance;
 
-use LucDeBrouwer\Distance\Distance;
-use LucDeBrouwer\Distance\Formula;
-use LucDeBrouwer\Distance\Unit;
+use ldebrouwer\Distance\Distance;
+use ldebrouwer\Distance\Formula;
+use ldebrouwer\Distance\Unit;
 use PHPUnit\Framework\Attributes\Test;
 use PHPUnit\Framework\Attributes\TestWith;
 use PHPUnit\Framework\TestCase;

From 009e0d9129adc62a7f13abf7311112b727df5fc3 Mon Sep 17 00:00:00 2001
From: Luc De Brouwer <info@lucdebrouwer.nl>
Date: Mon, 23 Feb 2026 19:56:12 +0000
Subject: [PATCH 09/11] Remove .travis.yml.

---
 .travis.yml | 17 -----------------
 1 file changed, 17 deletions(-)
 delete mode 100644 .travis.yml

diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index deb51d8..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,17 +0,0 @@
-language: php
-
-php:
-  - 5.5
-  - 5.6
-  - 7.0
-  - hhvm
-
-matrix:
-    allow_failures:
-        - php: 7.0
-
-sudo: false
-
-install: travis_retry composer install --no-interaction --prefer-source
-
-script: vendor/bin/phpunit
\ No newline at end of file

From 570692382bda72e60dedb9a3d879cbe318d03124 Mon Sep 17 00:00:00 2001
From: Luc De Brouwer <info@lucdebrouwer.nl>
Date: Mon, 23 Feb 2026 20:08:31 +0000
Subject: [PATCH 10/11] Remove obsolete getters.

---
 src/Distance.php       | 18 +-----------------
 tests/DistanceTest.php | 18 ------------------
 2 files changed, 1 insertion(+), 35 deletions(-)

diff --git a/src/Distance.php b/src/Distance.php
index b12b10a..0212b4c 100644
--- a/src/Distance.php
+++ b/src/Distance.php
@@ -24,7 +24,7 @@ class Distance
      */
     public function between(float $latitudeA, float $longitudeA, float $latitudeB, float $longitudeB): float
     {
-        $distanceInMeters = match ($this->getFormula()) {
+        $distanceInMeters = match ($this->formula) {
             Formula::VINCENTY => $this->betweenVincenty($latitudeA, $longitudeA, $latitudeB, $longitudeB),
             Formula::HAVERSINE => $this->betweenHaversine($latitudeA, $longitudeA, $latitudeB, $longitudeB),
         };
@@ -70,14 +70,6 @@ private function convert(float $distance): float
         return $distance * $this->unit->multiplierFromMetres();
     }
 
-    /**
-     * Returns the currently set formula used for distance calculation.
-     */
-    public function getFormula(): Formula
-    {
-        return $this->formula;
-    }
-
     /**
      * Sets the formula to be used for distance calculation.
      */
@@ -88,14 +80,6 @@ public function setFormula(Formula $formula): self
         return $this;
     }
 
-    /**
-     * Returns the currently set unit used when returning the distance between two coordinates.
-     */
-    public function getUnit(): Unit
-    {
-        return $this->unit;
-    }
-
     /**
      * Sets the unit to be used when returning the distance between two coordinates.
      */
diff --git a/tests/DistanceTest.php b/tests/DistanceTest.php
index f4ffc5c..f01e3ef 100644
--- a/tests/DistanceTest.php
+++ b/tests/DistanceTest.php
@@ -18,24 +18,6 @@ class DistanceTest extends TestCase
     private const float LATITUDE_B = 37.422546;
     private const float LONGITUDE_B = -122.084250;
 
-    #[Test]
-    public function canSetUnit(): void
-    {
-        $distance = new Distance();
-        $distance->setUnit(Unit::MILES);
-
-        self::assertSame(Unit::MILES, $distance->getUnit());
-    }
-
-    #[Test]
-    public function canSetFormula(): void
-    {
-        $distance = new Distance();
-        $distance->setFormula(Formula::VINCENTY);
-
-        self::assertSame(Formula::VINCENTY, $distance->getFormula());
-    }
-
     #[Test]
     #[TestWith([Unit::METRES, 11164.0])]
     #[TestWith([Unit::KILOMETRES, 11.164])]

From 295a2e34aec1f92b520406f4595771a759cb2ab9 Mon Sep 17 00:00:00 2001
From: Luc De Brouwer <info@lucdebrouwer.nl>
Date: Mon, 23 Feb 2026 20:19:07 +0000
Subject: [PATCH 11/11] Update README.md.

---
 README.md | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index 3517722..b9b96ec 100644
--- a/README.md
+++ b/README.md
@@ -16,15 +16,20 @@ When using [Composer](https://getcomposer.org) you can always load in the latest
 ```bash
 {
     "require": {
-        "ldebrouwer/distance": "~0.2"
+        "ldebrouwer/distance": "^1.0"
     }
 }
 ```
 Check it out [on Packagist](https://packagist.org/packages/ldebrouwer/distance).
 
-## Documentation
+## Usage
 
-This is still on the to-do list. The code is pretty well documented though and should autocomplete in most IDEs.
+```php
+$distance = new Distance()
+    ->setFormula(Formula::HAVERSINE)
+    ->setUnit(Unit::KILOMETRES)
+    ->between(37.331741, -122.030333, 37.422546, -122.084250);
+```
 
 ## Still to come
 - Expanded unit support.