From 3dddfc05db25a6a62a7f9da1347604f781838307 Mon Sep 17 00:00:00 2001
From: Jens True <jens.chr.true@gmail.com>
Date: Fri, 2 Feb 2024 14:53:38 +0000
Subject: [PATCH] More code standards

---
 benchmark/BasicBench.php                      |  8 +++++++
 src/FactorGraphs/Factor.php                   |  3 +++
 src/FactorGraphs/FactorGraphLayer.php         |  7 ++++--
 src/FactorGraphs/FactorList.php               |  2 ++
 src/FactorGraphs/ScheduleLoop.php             |  2 ++
 src/FactorGraphs/ScheduleSequence.php         |  2 ++
 src/FactorGraphs/ScheduleStep.php             |  2 ++
 src/FactorGraphs/Variable.php                 |  2 ++
 src/FactorGraphs/VariableFactory.php          |  2 ++
 src/GameInfo.php                              |  5 +++-
 src/Guard.php                                 |  2 +-
 src/Numerics/DiagonalMatrix.php               |  2 ++
 src/Numerics/Matrix.php                       | 10 ++++----
 src/RankSorter.php                            |  7 ++++--
 src/SkillCalculator.php                       | 13 +++++++----
 src/Team.php                                  |  2 +-
 src/Teams.php                                 |  2 ++
 src/TeamsRange.php                            |  2 ++
 src/TrueSkill/DrawMargin.php                  |  2 ++
 .../Factors/GaussianWeightedSumFactor.php     |  2 ++
 .../IteratedTeamDifferencesInnerLayer.php     |  2 ++
 ...yerPerformancesToTeamPerformancesLayer.php |  4 +++-
 .../Layers/PlayerPriorValuesToSkillsLayer.php |  2 ++
 .../PlayerSkillsToPerformancesLayer.php       |  2 ++
 .../Layers/TeamDifferencesComparisonLayer.php |  2 ++
 ...ancesToTeamPerformanceDifferencesLayer.php |  2 ++
 src/TrueSkill/TrueSkillFactorGraph.php        | 10 ++++----
 .../TruncatedGaussianCorrectionFunctions.php  |  2 ++
 .../TwoPlayerTrueSkillCalculator.php          |  2 ++
 src/TrueSkill/TwoTeamTrueSkillCalculator.php  |  2 ++
 tests/FactorGraphs/ScheduleStepTest.php       |  2 ++
 tests/FactorGraphs/VariableTest.php           |  5 +++-
 tests/GuardTest.php                           |  6 +++--
 tests/Numerics/BasicMathTest.php              |  2 ++
 tests/Numerics/GaussianDistributionTest.php   | 16 +++++++------
 tests/Numerics/MatrixTest.php                 |  4 +++-
 tests/Numerics/RangeTest.php                  |  4 +++-
 tests/PlayerTest.php                          |  4 +++-
 tests/RankSorterTest.php                      |  2 ++
 tests/RatingTest.php                          | 10 ++++----
 tests/TrueSkill/DrawMarginTest.php            |  4 +++-
 ...FactorGraphTeamTrueSkillCalculatorTest.php |  6 +++--
 .../FactorGraphTrueSkillCalculatorTest.php    |  6 +++--
 tests/TrueSkill/TrueSkillCalculatorTests.php  | 23 ++++++++++---------
 .../TwoPlayerTrueSkillCalculatorTest.php      |  4 +++-
 .../TwoTeamTrueSkillCalculatorTest.php        |  4 +++-
 46 files changed, 156 insertions(+), 55 deletions(-)

diff --git a/benchmark/BasicBench.php b/benchmark/BasicBench.php
index 2303fc9..fd42365 100644
--- a/benchmark/BasicBench.php
+++ b/benchmark/BasicBench.php
@@ -15,6 +15,8 @@ use DNW\Skills\Teams;
 class BasicBench
 {
     /**
+     * To benchmark performance when using TwoPlayerTrueSkillCalculator
+     *
      * @Revs(20)
      * @Iterations(20)
      */
@@ -44,6 +46,8 @@ class BasicBench
     }
 
     /**
+     * To benchmark performance when using TwoTeamTrueSkillCalculator for just two players in two teams
+     *
      * @Revs(20)
      * @Iterations(20)
      */
@@ -73,6 +77,8 @@ class BasicBench
     }
 
     /**
+     * To benchmark performance when using FactorGraphTrueSkillCalculator for just two players in two teams
+     *
      * @Revs(20)
      * @Iterations(20)
      */
@@ -102,6 +108,8 @@ class BasicBench
     }
 
     /**
+     * To benchmark performance when using FactorGraphTrueSkillCalculator with 3 players in 3 teams
+     *
      * @Revs(20)
      * @Iterations(20)
      */
diff --git a/src/FactorGraphs/Factor.php b/src/FactorGraphs/Factor.php
index 81b9169..d1c5636 100644
--- a/src/FactorGraphs/Factor.php
+++ b/src/FactorGraphs/Factor.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\FactorGraphs;
 
 use DNW\Skills\Guard;
@@ -94,6 +96,7 @@ abstract class Factor implements \Stringable
 
     /**
      * Sends the ith message to the marginal and returns the log-normalization constant
+     *
      * @throws Exception
      */
     public function sendMessageIndex(int $messageIndex): float|int
diff --git a/src/FactorGraphs/FactorGraphLayer.php b/src/FactorGraphs/FactorGraphLayer.php
index ca2cb8c..4e39789 100644
--- a/src/FactorGraphs/FactorGraphLayer.php
+++ b/src/FactorGraphs/FactorGraphLayer.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\FactorGraphs;
 
 use DNW\Skills\FactorGraphs\ScheduleSequence;
@@ -42,6 +44,7 @@ abstract class FactorGraphLayer
 
     /**
      * This reference is still needed
+     *
      * @return array<int,array<int,object>>
      */
     public function &getOutputVariablesGroups(): array
@@ -82,11 +85,11 @@ abstract class FactorGraphLayer
 
     public function createPriorSchedule(): ?ScheduleSequence
     {
-        return null;
+        return NULL;
     }
 
     public function createPosteriorSchedule(): ?ScheduleSequence
     {
-        return null;
+        return NULL;
     }
 }
diff --git a/src/FactorGraphs/FactorList.php b/src/FactorGraphs/FactorList.php
index 8fec3d2..390a029 100644
--- a/src/FactorGraphs/FactorList.php
+++ b/src/FactorGraphs/FactorList.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\FactorGraphs;
 
 /**
diff --git a/src/FactorGraphs/ScheduleLoop.php b/src/FactorGraphs/ScheduleLoop.php
index 56d00ca..3d3c2ab 100644
--- a/src/FactorGraphs/ScheduleLoop.php
+++ b/src/FactorGraphs/ScheduleLoop.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\FactorGraphs;
 
 class ScheduleLoop extends Schedule
diff --git a/src/FactorGraphs/ScheduleSequence.php b/src/FactorGraphs/ScheduleSequence.php
index c1b7d4c..1475e69 100644
--- a/src/FactorGraphs/ScheduleSequence.php
+++ b/src/FactorGraphs/ScheduleSequence.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\FactorGraphs;
 
 class ScheduleSequence extends Schedule
diff --git a/src/FactorGraphs/ScheduleStep.php b/src/FactorGraphs/ScheduleStep.php
index 00b5b23..9737370 100644
--- a/src/FactorGraphs/ScheduleStep.php
+++ b/src/FactorGraphs/ScheduleStep.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\FactorGraphs;
 
 class ScheduleStep extends Schedule
diff --git a/src/FactorGraphs/Variable.php b/src/FactorGraphs/Variable.php
index e3c76d6..67b0357 100644
--- a/src/FactorGraphs/Variable.php
+++ b/src/FactorGraphs/Variable.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\FactorGraphs;
 
 use DNW\Skills\Numerics\GaussianDistribution;
diff --git a/src/FactorGraphs/VariableFactory.php b/src/FactorGraphs/VariableFactory.php
index 9790770..1cc5f1f 100644
--- a/src/FactorGraphs/VariableFactory.php
+++ b/src/FactorGraphs/VariableFactory.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\FactorGraphs;
 
 class VariableFactory
diff --git a/src/GameInfo.php b/src/GameInfo.php
index 3f2e8e9..01e2afc 100644
--- a/src/GameInfo.php
+++ b/src/GameInfo.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills;
 
 /**
@@ -23,7 +25,8 @@ class GameInfo
         private float $beta = self::DEFAULT_BETA,
         private float $dynamicsFactor = self::DEFAULT_DYNAMICS_FACTOR,
         private float $drawProbability = self::DEFAULT_DRAW_PROBABILITY
-    ) {
+    )
+    {
     }
 
     public function getInitialMean(): float
diff --git a/src/Guard.php b/src/Guard.php
index 0c4b915..96ee1da 100644
--- a/src/Guard.php
+++ b/src/Guard.php
@@ -13,7 +13,7 @@ class Guard
 {
     public static function argumentNotNull(mixed $value, string $parameterName): void
     {
-        if ($value == null) {
+        if ($value == NULL) {
             throw new Exception($parameterName . ' can not be null');
         }
     }
diff --git a/src/Numerics/DiagonalMatrix.php b/src/Numerics/DiagonalMatrix.php
index c6882e1..6802763 100644
--- a/src/Numerics/DiagonalMatrix.php
+++ b/src/Numerics/DiagonalMatrix.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\Numerics;
 
 class DiagonalMatrix extends Matrix
diff --git a/src/Numerics/Matrix.php b/src/Numerics/Matrix.php
index 0f6edda..edc5d9b 100644
--- a/src/Numerics/Matrix.php
+++ b/src/Numerics/Matrix.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\Numerics;
 
 use Exception;
@@ -11,7 +13,7 @@ class Matrix
     /**
      * @param array<int,array<int,float>> $matrixRowData
      */
-    public function __construct(private int $rowCount = 0, private int $columnCount = 0, private array $matrixRowData = array())
+    public function __construct(private int $rowCount = 0, private int $columnCount = 0, private array $matrixRowData = [])
     {
     }
 
@@ -307,7 +309,7 @@ class Matrix
     public function equals(Matrix $otherMatrix): bool
     {
         if (($this->rowCount != $otherMatrix->getRowCount()) || ($this->columnCount != $otherMatrix->getColumnCount())) {
-            return false;
+            return FALSE;
         }
 
         for ($currentRow = 0; $currentRow < $this->rowCount; $currentRow++) {
@@ -319,11 +321,11 @@ class Matrix
                     );
 
                 if ($delta > self::ERROR_TOLERANCE) {
-                    return false;
+                    return FALSE;
                 }
             }
         }
 
-        return true;
+        return TRUE;
     }
 }
diff --git a/src/RankSorter.php b/src/RankSorter.php
index 8f8f26a..3f75a97 100644
--- a/src/RankSorter.php
+++ b/src/RankSorter.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills;
 
 /**
@@ -10,8 +12,9 @@ class RankSorter
     /**
      * Performs an in-place sort of the items in according to the ranks in non-decreasing order.
      *
-     * @param  array<mixed> $teams     The items to sort according to the order specified by ranks.
-     * @param  array<int>   $teamRanks The ranks for each item where 1 is first place.
+     * @param array<mixed> $teams     The items to sort according to the order specified by ranks.
+     * @param array<int>   $teamRanks The ranks for each item where 1 is first place.
+     *
      * @return array<int>
      */
     public static function sort(array &$teams, array &$teamRanks): array
diff --git a/src/SkillCalculator.php b/src/SkillCalculator.php
index b8df1d5..5fe94cb 100644
--- a/src/SkillCalculator.php
+++ b/src/SkillCalculator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills;
 
 use Exception;
@@ -13,15 +15,17 @@ abstract class SkillCalculator
         private int $supportedOptions,
         private readonly TeamsRange $totalTeamsAllowed,
         private readonly PlayersRange $playersPerTeamAllowed
-    ) {
+    )
+    {
     }
 
     /**
      * Calculates new ratings based on the prior ratings and team ranks.
      *
-     * @param  GameInfo $gameInfo  Parameters for the game.
-     * @param  Team[]   $teams     A mapping of team players and their ratings.
-     * @param  int[]    $teamRanks The ranks of the teams where 1 is first place. For a tie, repeat the number (e.g. 1, 2, 2).
+     * @param GameInfo $gameInfo  Parameters for the game.
+     * @param Team[]   $teams     A mapping of team players and their ratings.
+     * @param int[]    $teamRanks The ranks of the teams where 1 is first place. For a tie, repeat the number (e.g. 1, 2, 2).
+     *
      * @return RatingContainer All the players and their new ratings.
      */
     abstract public function calculateNewRatings(
@@ -35,6 +39,7 @@ abstract class SkillCalculator
      *
      * @param  GameInfo $gameInfo Parameters for the game.
      * @param  Team[]   $teams    A mapping of team players and their ratings.
+     *
      * @return float The quality of the match between the teams as a percentage (0% = bad, 100% = well matched).
      */
     abstract public function calculateMatchQuality(GameInfo $gameInfo, array $teams): float;
diff --git a/src/Team.php b/src/Team.php
index 298fe87..fdef41c 100644
--- a/src/Team.php
+++ b/src/Team.php
@@ -4,7 +4,7 @@ namespace DNW\Skills;
 
 class Team extends RatingContainer
 {
-    public function __construct(Player $player = null, Rating $rating = null)
+    public function __construct(Player $player = NULL, Rating $rating = NULL)
     {
         parent::__construct();
 
diff --git a/src/Teams.php b/src/Teams.php
index 0e90919..341d851 100644
--- a/src/Teams.php
+++ b/src/Teams.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills;
 
 class Teams
diff --git a/src/TeamsRange.php b/src/TeamsRange.php
index 7d53bef..70b6518 100644
--- a/src/TeamsRange.php
+++ b/src/TeamsRange.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills;
 
 use DNW\Skills\Numerics\Range;
diff --git a/src/TrueSkill/DrawMargin.php b/src/TrueSkill/DrawMargin.php
index 9f09d2c..5dc4aac 100644
--- a/src/TrueSkill/DrawMargin.php
+++ b/src/TrueSkill/DrawMargin.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\TrueSkill;
 
 use DNW\Skills\Numerics\GaussianDistribution;
diff --git a/src/TrueSkill/Factors/GaussianWeightedSumFactor.php b/src/TrueSkill/Factors/GaussianWeightedSumFactor.php
index 5b9b23e..4550312 100644
--- a/src/TrueSkill/Factors/GaussianWeightedSumFactor.php
+++ b/src/TrueSkill/Factors/GaussianWeightedSumFactor.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\TrueSkill\Factors;
 
 use DNW\Skills\FactorGraphs\Message;
diff --git a/src/TrueSkill/Layers/IteratedTeamDifferencesInnerLayer.php b/src/TrueSkill/Layers/IteratedTeamDifferencesInnerLayer.php
index 76dc02f..1d2e3ef 100644
--- a/src/TrueSkill/Layers/IteratedTeamDifferencesInnerLayer.php
+++ b/src/TrueSkill/Layers/IteratedTeamDifferencesInnerLayer.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\TrueSkill\Layers;
 
 use DNW\Skills\FactorGraphs\ScheduleLoop;
diff --git a/src/TrueSkill/Layers/PlayerPerformancesToTeamPerformancesLayer.php b/src/TrueSkill/Layers/PlayerPerformancesToTeamPerformancesLayer.php
index 490b47a..5b08146 100644
--- a/src/TrueSkill/Layers/PlayerPerformancesToTeamPerformancesLayer.php
+++ b/src/TrueSkill/Layers/PlayerPerformancesToTeamPerformancesLayer.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\TrueSkill\Layers;
 
 use DNW\Skills\FactorGraphs\ScheduleStep;
@@ -87,7 +89,7 @@ class PlayerPerformancesToTeamPerformancesLayer extends TrueSkillFactorGraphLaye
      */
     private function createOutputVariable(array $team): Variable
     {
-        $memberNames = array_map(fn ($currentPlayer) => (string) ($currentPlayer->getKey()), $team);
+        $memberNames = array_map(fn ($currentPlayer) => (string)($currentPlayer->getKey()), $team);
 
         $teamMemberNames = \implode(', ', $memberNames);
 
diff --git a/src/TrueSkill/Layers/PlayerPriorValuesToSkillsLayer.php b/src/TrueSkill/Layers/PlayerPriorValuesToSkillsLayer.php
index ac1b3d5..e359164 100644
--- a/src/TrueSkill/Layers/PlayerPriorValuesToSkillsLayer.php
+++ b/src/TrueSkill/Layers/PlayerPriorValuesToSkillsLayer.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\TrueSkill\Layers;
 
 use DNW\Skills\FactorGraphs\ScheduleStep;
diff --git a/src/TrueSkill/Layers/PlayerSkillsToPerformancesLayer.php b/src/TrueSkill/Layers/PlayerSkillsToPerformancesLayer.php
index 4870e17..525acde 100644
--- a/src/TrueSkill/Layers/PlayerSkillsToPerformancesLayer.php
+++ b/src/TrueSkill/Layers/PlayerSkillsToPerformancesLayer.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\TrueSkill\Layers;
 
 use DNW\Skills\FactorGraphs\KeyedVariable;
diff --git a/src/TrueSkill/Layers/TeamDifferencesComparisonLayer.php b/src/TrueSkill/Layers/TeamDifferencesComparisonLayer.php
index 6b3b06e..d0e1b0a 100644
--- a/src/TrueSkill/Layers/TeamDifferencesComparisonLayer.php
+++ b/src/TrueSkill/Layers/TeamDifferencesComparisonLayer.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\TrueSkill\Layers;
 
 use DNW\Skills\TrueSkill\DrawMargin;
diff --git a/src/TrueSkill/Layers/TeamPerformancesToTeamPerformanceDifferencesLayer.php b/src/TrueSkill/Layers/TeamPerformancesToTeamPerformanceDifferencesLayer.php
index 00e5adc..e529d05 100644
--- a/src/TrueSkill/Layers/TeamPerformancesToTeamPerformanceDifferencesLayer.php
+++ b/src/TrueSkill/Layers/TeamPerformancesToTeamPerformanceDifferencesLayer.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\TrueSkill\Layers;
 
 use DNW\Skills\FactorGraphs\Variable;
diff --git a/src/TrueSkill/TrueSkillFactorGraph.php b/src/TrueSkill/TrueSkillFactorGraph.php
index c10179c..c8a3962 100644
--- a/src/TrueSkill/TrueSkillFactorGraph.php
+++ b/src/TrueSkill/TrueSkillFactorGraph.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\TrueSkill;
 
 use DNW\Skills\FactorGraphs\FactorGraph;
@@ -60,11 +62,11 @@ class TrueSkillFactorGraph extends FactorGraph
 
     public function buildGraph(): void
     {
-        $lastOutput = null;
+        $lastOutput = NULL;
 
         $layers = $this->layers;
         foreach ($layers as $currentLayer) {
-            if ($lastOutput != null) {
+            if ($lastOutput != NULL) {
                 $currentLayer->setInputVariablesGroups($lastOutput);
             }
 
@@ -105,7 +107,7 @@ class TrueSkillFactorGraph extends FactorGraph
         $layers = $this->layers;
         foreach ($layers as $currentLayer) {
             $currentPriorSchedule = $currentLayer->createPriorSchedule();
-            if ($currentPriorSchedule != null) {
+            if ($currentPriorSchedule != NULL) {
                 $fullSchedule[] = $currentPriorSchedule;
             }
         }
@@ -114,7 +116,7 @@ class TrueSkillFactorGraph extends FactorGraph
 
         foreach ($allLayersReverse as $currentLayer) {
             $currentPosteriorSchedule = $currentLayer->createPosteriorSchedule();
-            if ($currentPosteriorSchedule != null) {
+            if ($currentPosteriorSchedule != NULL) {
                 $fullSchedule[] = $currentPosteriorSchedule;
             }
         }
diff --git a/src/TrueSkill/TruncatedGaussianCorrectionFunctions.php b/src/TrueSkill/TruncatedGaussianCorrectionFunctions.php
index c52cfc8..9cfdc89 100644
--- a/src/TrueSkill/TruncatedGaussianCorrectionFunctions.php
+++ b/src/TrueSkill/TruncatedGaussianCorrectionFunctions.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\TrueSkill;
 
 use DNW\Skills\Numerics\GaussianDistribution;
diff --git a/src/TrueSkill/TwoPlayerTrueSkillCalculator.php b/src/TrueSkill/TwoPlayerTrueSkillCalculator.php
index 98adc33..c1cd536 100644
--- a/src/TrueSkill/TwoPlayerTrueSkillCalculator.php
+++ b/src/TrueSkill/TwoPlayerTrueSkillCalculator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\TrueSkill;
 
 use DNW\Skills\GameInfo;
diff --git a/src/TrueSkill/TwoTeamTrueSkillCalculator.php b/src/TrueSkill/TwoTeamTrueSkillCalculator.php
index 06b7411..7661627 100644
--- a/src/TrueSkill/TwoTeamTrueSkillCalculator.php
+++ b/src/TrueSkill/TwoTeamTrueSkillCalculator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\TrueSkill;
 
 use DNW\Skills\GameInfo;
diff --git a/tests/FactorGraphs/ScheduleStepTest.php b/tests/FactorGraphs/ScheduleStepTest.php
index b99b5f0..d5865b1 100644
--- a/tests/FactorGraphs/ScheduleStepTest.php
+++ b/tests/FactorGraphs/ScheduleStepTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\Tests\FactorGraphs;
 
 use DNW\Skills\FactorGraphs\ScheduleStep;
diff --git a/tests/FactorGraphs/VariableTest.php b/tests/FactorGraphs/VariableTest.php
index 3a2de37..1cef70f 100644
--- a/tests/FactorGraphs/VariableTest.php
+++ b/tests/FactorGraphs/VariableTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\Tests\FactorGraphs;
 
 use DNW\Skills\FactorGraphs\Variable;
@@ -11,8 +13,9 @@ class VariableTest extends TestCase
     public function test(): void
     {
         $gd_prior = new GaussianDistribution();
-        $var = new Variable('dummy', $gd_prior);
+        $var      = new Variable('dummy', $gd_prior);
         $this->assertEquals($gd_prior, $var->getValue());
+
         $gd_new = new GaussianDistribution();
         $this->assertEquals($gd_new, $var->getValue());
         $var->resetToPrior();
diff --git a/tests/GuardTest.php b/tests/GuardTest.php
index 18d95af..285e965 100644
--- a/tests/GuardTest.php
+++ b/tests/GuardTest.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace DNW\Skills\Tests;
 
@@ -12,7 +14,7 @@ class GuardTest extends TestCase
     {
         $this->expectException(Exception::class);
         $this->expectExceptionMessage('dummy can not be null');
-        Guard::argumentNotNull(null, "dummy");
+        Guard::argumentNotNull(NULL, "dummy");
     }
 
     public function testargumentIsValidIndex(): void
diff --git a/tests/Numerics/BasicMathTest.php b/tests/Numerics/BasicMathTest.php
index 6574a73..24085c0 100644
--- a/tests/Numerics/BasicMathTest.php
+++ b/tests/Numerics/BasicMathTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\Tests\Numerics;
 
 use DNW\Skills\Numerics\BasicMath;
diff --git a/tests/Numerics/GaussianDistributionTest.php b/tests/Numerics/GaussianDistributionTest.php
index 4d3829f..27081f5 100644
--- a/tests/Numerics/GaussianDistributionTest.php
+++ b/tests/Numerics/GaussianDistributionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\Tests\Numerics;
 
 use DNW\Skills\Numerics\BasicMath;
@@ -39,9 +41,9 @@ class GaussianDistributionTest extends TestCase
     public function testMultiplication(): void
     {
         // I verified this against the formula at http://www.tina-vision.net/tina-knoppix/tina-memo/2003-003.pdf
-        $standardNormal = new GaussianDistribution(0, 1);
+        $standardNormal  = new GaussianDistribution(0, 1);
         $shiftedGaussian = new GaussianDistribution(2, 3);
-        $product = GaussianDistribution::multiply($standardNormal, $shiftedGaussian);
+        $product         = GaussianDistribution::multiply($standardNormal, $shiftedGaussian);
 
         $this->assertEqualsWithDelta(0.2, $product->getMean(), GaussianDistributionTest::ERROR_TOLERANCE);
         $this->assertEqualsWithDelta(3.0 / sqrt(10), $product->getStandardDeviation(), GaussianDistributionTest::ERROR_TOLERANCE);
@@ -61,15 +63,15 @@ class GaussianDistributionTest extends TestCase
     public function testDivision(): void
     {
         // Since the multiplication was worked out by hand, we use the same numbers but work backwards
-        $product = new GaussianDistribution(0.2, 3.0 / sqrt(10));
+        $product        = new GaussianDistribution(0.2, 3.0 / sqrt(10));
         $standardNormal = new GaussianDistribution(0, 1);
 
         $productDividedByStandardNormal = GaussianDistribution::divide($product, $standardNormal);
         $this->assertEqualsWithDelta(2.0, $productDividedByStandardNormal->getMean(), GaussianDistributionTest::ERROR_TOLERANCE);
         $this->assertEqualsWithDelta(3.0, $productDividedByStandardNormal->getStandardDeviation(), GaussianDistributionTest::ERROR_TOLERANCE);
 
-        $product2 = new GaussianDistribution((4 * BasicMath::square(7) + 6 * BasicMath::square(5)) / (BasicMath::square(5) + BasicMath::square(7)), sqrt(((BasicMath::square(5) * BasicMath::square(7)) / (BasicMath::square(5) + BasicMath::square(7)))));
-        $m4s5 = new GaussianDistribution(4, 5);
+        $product2              = new GaussianDistribution((4 * BasicMath::square(7) + 6 * BasicMath::square(5)) / (BasicMath::square(5) + BasicMath::square(7)), sqrt(((BasicMath::square(5) * BasicMath::square(7)) / (BasicMath::square(5) + BasicMath::square(7)))));
+        $m4s5                  = new GaussianDistribution(4, 5);
         $product2DividedByM4S5 = GaussianDistribution::divide($product2, $m4s5);
         $this->assertEqualsWithDelta(6.0, $product2DividedByM4S5->getMean(), GaussianDistributionTest::ERROR_TOLERANCE);
         $this->assertEqualsWithDelta(7.0, $product2DividedByM4S5->getStandardDeviation(), GaussianDistributionTest::ERROR_TOLERANCE);
@@ -93,7 +95,7 @@ class GaussianDistributionTest extends TestCase
         // Verified with Ralf Herbrich's F# implementation
         $m1s2 = new GaussianDistribution(1, 2);
         $m3s4 = new GaussianDistribution(3, 4);
-        $lrn = GaussianDistribution::logRatioNormalization($m1s2, $m3s4);
+        $lrn  = GaussianDistribution::logRatioNormalization($m1s2, $m3s4);
         $this->assertEqualsWithDelta(2.6157405972171204, $lrn, GaussianDistributionTest::ERROR_TOLERANCE);
     }
 
@@ -101,7 +103,7 @@ class GaussianDistributionTest extends TestCase
     {
         // Verified with Ralf Herbrich's F# implementation
         $standardNormal = new GaussianDistribution(0, 1);
-        $absDiff = GaussianDistribution::absoluteDifference($standardNormal, $standardNormal);
+        $absDiff        = GaussianDistribution::absoluteDifference($standardNormal, $standardNormal);
         $this->assertEqualsWithDelta(0.0, $absDiff, GaussianDistributionTest::ERROR_TOLERANCE);
 
         $m1s2 = new GaussianDistribution(1, 2);
diff --git a/tests/Numerics/MatrixTest.php b/tests/Numerics/MatrixTest.php
index 70843a1..56bceaa 100644
--- a/tests/Numerics/MatrixTest.php
+++ b/tests/Numerics/MatrixTest.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace DNW\Skills\Tests\Numerics;
 
diff --git a/tests/Numerics/RangeTest.php b/tests/Numerics/RangeTest.php
index b5504b4..ad974b5 100644
--- a/tests/Numerics/RangeTest.php
+++ b/tests/Numerics/RangeTest.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace DNW\Skills\Tests\Numerics;
 
diff --git a/tests/PlayerTest.php b/tests/PlayerTest.php
index 9d14b37..2792e1e 100644
--- a/tests/PlayerTest.php
+++ b/tests/PlayerTest.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace DNW\Skills\Tests;
 
diff --git a/tests/RankSorterTest.php b/tests/RankSorterTest.php
index 2974d01..7b98e4f 100644
--- a/tests/RankSorterTest.php
+++ b/tests/RankSorterTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\Tests;
 
 use DNW\Skills\RankSorter;
diff --git a/tests/RatingTest.php b/tests/RatingTest.php
index 7680939..bdd8603 100644
--- a/tests/RatingTest.php
+++ b/tests/RatingTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace DNW\Skills\Tests;
 
 use DNW\Skills\Rating;
@@ -18,11 +20,11 @@ class RatingTest extends TestCase
 
     public function testPartialUpdate(): void
     {
-        $rating = new Rating(100, 10, 5);
-        $rating_prior = new Rating(100, 10, 5);
-        $rating_new = new Rating(200, 10, 5);
+        $rating    = new Rating(100, 10, 5);
+        $ratingOld = new Rating(100, 10, 5);
+        $ratingNew = new Rating(200, 10, 5);
 
-        $rating_partial = $rating ->getPartialUpdate($rating_prior, $rating_new, 0.5);
+        $rating_partial = $rating->getPartialUpdate($ratingOld, $ratingNew, 0.5);
 
 
         $this->assertEquals(150, $rating_partial->getMean());
diff --git a/tests/TrueSkill/DrawMarginTest.php b/tests/TrueSkill/DrawMarginTest.php
index 099a995..4584f9e 100644
--- a/tests/TrueSkill/DrawMarginTest.php
+++ b/tests/TrueSkill/DrawMarginTest.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace DNW\Skills\Tests\TrueSkill;
 
diff --git a/tests/TrueSkill/FactorGraphTeamTrueSkillCalculatorTest.php b/tests/TrueSkill/FactorGraphTeamTrueSkillCalculatorTest.php
index 8ca133d..7870875 100644
--- a/tests/TrueSkill/FactorGraphTeamTrueSkillCalculatorTest.php
+++ b/tests/TrueSkill/FactorGraphTeamTrueSkillCalculatorTest.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace DNW\Skills\Tests\TrueSkill;
 
@@ -21,6 +23,6 @@ class FactorGraphTeamTrueSkillCalculatorTest extends TestCase
     public function testMethodisSupported(): void
     {
         $calculator = new FactorGraphTrueSkillCalculator();
-        $this->assertEquals(true, $calculator->isSupported(SkillCalculatorSupportedOptions::PARTIAL_PLAY));
+        $this->assertEquals(TRUE, $calculator->isSupported(SkillCalculatorSupportedOptions::PARTIAL_PLAY));
     }
 }
diff --git a/tests/TrueSkill/FactorGraphTrueSkillCalculatorTest.php b/tests/TrueSkill/FactorGraphTrueSkillCalculatorTest.php
index 8d07888..54227df 100644
--- a/tests/TrueSkill/FactorGraphTrueSkillCalculatorTest.php
+++ b/tests/TrueSkill/FactorGraphTrueSkillCalculatorTest.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace DNW\Skills\Tests\TrueSkill;
 
@@ -25,7 +27,7 @@ class FactorGraphTrueSkillCalculatorTest extends TestCase
             new Player("hillary"),
         ];
 
-        $teams = array();
+        $teams = [];
         foreach ($players as $player) {
             $teams[] = new Team($player, $gameInfo->getDefaultRating());
         }
diff --git a/tests/TrueSkill/TrueSkillCalculatorTests.php b/tests/TrueSkill/TrueSkillCalculatorTests.php
index 4ef743e..680a9e0 100644
--- a/tests/TrueSkill/TrueSkillCalculatorTests.php
+++ b/tests/TrueSkill/TrueSkillCalculatorTests.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace DNW\Skills\Tests\TrueSkill;
 
@@ -78,8 +80,8 @@ class TrueSkillCalculatorTests
 
     private static function twoPlayerTestNotDrawn(TestCase $testClass, SkillCalculator $calculator): void
     {
-        $player1 = new Player(1);
-        $player2 = new Player(2);
+        $player1  = new Player(1);
+        $player2  = new Player(2);
         $gameInfo = new GameInfo();
 
         $team1 = new Team($player1, $gameInfo->getDefaultRating());
@@ -108,6 +110,7 @@ class TrueSkillCalculatorTests
         $team2 = new Team($player2, $gameInfo->getDefaultRating());
 
         $teams = Teams::concat($team1, $team2);
+
         $newRatings = $calculator->calculateNewRatings($gameInfo, $teams, [1, 1]);
 
         $player1NewRating = $newRatings->getRating($player1);
@@ -122,8 +125,8 @@ class TrueSkillCalculatorTests
     private static function twoPlayerChessTestNotDrawn(TestCase $testClass, SkillCalculator $calculator): void
     {
         // Inspired by a real bug :-)
-        $player1 = new Player(1);
-        $player2 = new Player(2);
+        $player1  = new Player(1);
+        $player2  = new Player(2);
         $gameInfo = new GameInfo(1200.0, 1200.0 / 3.0, 200.0, 1200.0 / 300.0, 0.03);
 
         $team1 = new Team($player1, new Rating(1301.0007, 42.9232));
@@ -169,11 +172,9 @@ class TrueSkillCalculatorTests
 
     private static function oneOnTwoSimpleTest(TestCase $testClass, SkillCalculator $calculator): void
     {
-        $player1 = new Player(1);
-
+        $player1  = new Player(1);
         $gameInfo = new GameInfo();
-
-        $team1 = new Team();
+        $team1    = new Team();
         $team1->addPlayer($player1, $gameInfo->getDefaultRating());
 
         $player2 = new Player(2);
@@ -975,7 +976,7 @@ class TrueSkillCalculatorTests
     {
         $gameInfo = new GameInfo();
 
-        $p1 = new Player(1);
+        $p1    = new Player(1);
         $team1 = new Team($p1, $gameInfo->getDefaultRating());
 
         $p2 = new Player(2, 0.0);
@@ -985,7 +986,7 @@ class TrueSkillCalculatorTests
         $team2->addPlayer($p2, $gameInfo->getDefaultRating());
         $team2->addPlayer($p3, $gameInfo->getDefaultRating());
 
-        $teams = Teams::concat($team1, $team2);
+        $teams      = Teams::concat($team1, $team2);
         $newRatings = $calculator->calculateNewRatings($gameInfo, $teams, [1, 2]);
 
         $p1NewRating = $newRatings->getRating($p1);
diff --git a/tests/TrueSkill/TwoPlayerTrueSkillCalculatorTest.php b/tests/TrueSkill/TwoPlayerTrueSkillCalculatorTest.php
index 97b8466..43b63d6 100644
--- a/tests/TrueSkill/TwoPlayerTrueSkillCalculatorTest.php
+++ b/tests/TrueSkill/TwoPlayerTrueSkillCalculatorTest.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace DNW\Skills\Tests\TrueSkill;
 
diff --git a/tests/TrueSkill/TwoTeamTrueSkillCalculatorTest.php b/tests/TrueSkill/TwoTeamTrueSkillCalculatorTest.php
index dd1edf2..d1ad033 100644
--- a/tests/TrueSkill/TwoTeamTrueSkillCalculatorTest.php
+++ b/tests/TrueSkill/TwoTeamTrueSkillCalculatorTest.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace DNW\Skills\Tests\TrueSkill;