test adding condorcet vote

include/Condorcet/Tests/src/Algo/Tools/PermutationsTest.php

@@ -0,0 +1,75 @@
+<?php
+
+declare(strict_types=1);
+
+namespace CondorcetPHP\Condorcet\Tests\Algo\Tools;
+
+use CondorcetPHP\Condorcet\Algo\Tools\Permutations;
+use CondorcetPHP\Condorcet\Throwable\Internal\{CondorcetInternalException, IntegerOverflowException};
+use PHPUnit\Framework\TestCase;
+
+class PermutationsTest extends TestCase
+{
+    protected function tearDown(): void
+    {
+        Permutations::$useBigIntegerIfAvailable = true;
+    }
+
+    public function testCountPossiblePermutations(): void
+    {
+        self::assertSame(6, Permutations::getPossibleCountOfPermutations(3));
+
+        Permutations::$useBigIntegerIfAvailable = false;
+        self::assertSame(6, Permutations::getPossibleCountOfPermutations(3));
+
+        $this->expectException(CondorcetInternalException::class);
+        Permutations::getPossibleCountOfPermutations(0);
+    }
+
+    public function testIntegerOverflowWithBigInt(): void
+    {
+        $this->expectException(IntegerOverflowException::class);
+        Permutations::getPossibleCountOfPermutations(42);
+    }
+
+    public function testIntegerOverflowWithoutBigInt(): void
+    {
+        Permutations::$useBigIntegerIfAvailable = false;
+
+        $this->expectException(IntegerOverflowException::class);
+        Permutations::getPossibleCountOfPermutations(42);
+    }
+
+    public function testPermutationsAllResultsFor3(): void
+    {
+        $p = new Permutations([0, 1, 2]);
+
+        $r = $p->getResults();
+
+        self::assertInstanceOf(\SplFixedArray::class, $r);
+        self::assertSame(6, $r->getSize());
+
+        self::assertSame(
+            [[1=>0, 2=>1, 3=>2],
+                [1=>1, 2=>0, 3=>2],
+                [1=>1, 2=>2, 3=>0],
+                [1=>0, 2=>2, 3=>1],
+                [1=>2, 2=>0, 3=>1],
+                [1=>2, 2=>1, 3=>0],
+            ],
+            $r->toArray()
+        );
+    }
+
+    public function testPermutationsAllResultsFor1(): void
+    {
+        $p = new Permutations([42]);
+
+        $r = $p->getResults();
+
+        self::assertInstanceOf(\SplFixedArray::class, $r);
+        self::assertSame(1, $r->getSize());
+
+        self::assertSame([[1=>42]], $r->toArray());
+    }
+}