implementation d'une classe de collection

src/Collection.php

@@ -0,0 +1,86 @@
+<?php
+
+namespace Kletellier\PdoWrapper;
+
+use ArrayIterator;
+use IteratorAggregate;
+use Traversable;
+
+class Collection implements IteratorAggregate
+{
+    private array $elements;
+
+    public function __construct(array $elements = [])
+    {
+        $this->elements = $elements;
+    }
+
+    public function first(): mixed
+    {
+        return reset($this->elements);
+    }
+
+    public function last(): mixed
+    {
+        return end($this->elements);
+    }
+
+    public function count(): int
+    {
+        return count($this->elements);
+    }
+
+    public function clear(): bool
+    {
+        $this->elements = [];
+        return count($this->elements) == 0;
+    }
+
+    public function reduce(callable $fn, mixed $initial): mixed
+    {
+        return array_reduce($this->elements, $fn, $initial);
+    }
+
+    public function map(callable $fn): Collection
+    {
+        $tmp = array_map($fn, $this->elements);
+        return new Collection($tmp);
+    }
+
+    public function each(callable $fn): void
+    {
+        array_walk($this->elements, $fn);
+    }
+
+    public function filter(callable $fn): Collection
+    {
+        $tmp = array_filter($this->elements, $fn, ARRAY_FILTER_USE_BOTH);
+        $collect = new Collection($tmp);
+        return $collect;
+    }
+
+    public function empty(): bool
+    {
+        return empty($this->elements);
+    }
+
+    public function add(mixed $element): void
+    {
+        $this->elements[] = $element;
+    }
+
+    public function values(): array
+    {
+        return array_values($this->elements);
+    }
+
+    public function items(): array
+    {
+        return $this->elements;
+    }
+
+    public function getIterator(): Traversable
+    {
+        return new ArrayIterator($this->elements);
+    }
+}

tests/CollectionTest.php

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+<?php
+
+use Kletellier\PdoWrapper\Collection; 
+
+test("collection", function () {
+    $arr = [];
+    for ($i=0; $i < 11; $i++) { 
+        $arr[] = $i;
+    }
+
+    expect(count($arr))->toBe(11);
+
+    $coll = new Collection($arr);
+    expect($coll->count())->toBe(11);
+    expect($coll->first())->toBe(0);
+    expect($coll->last())->toBe(10);
+
+    $filt = $coll->filter(function($item){ return $item<5;});    
+    expect($filt)->toBeInstanceOf(Collection::class);
+    expect($filt->count())->toBe(5);
+    expect($filt->first())->toBe(0);
+    expect($filt->last())->toBe(4);
+
+    // no change in initial collection
+    expect($coll->count())->toBe(11);
+
+    expect($coll->empty())->toBe(false);
+
+    expect($coll->items())->toBeArray();
+    expect(count($coll->items()))->toBe(11);
+
+    $incr = 0;
+    $coll->each(function($item) use(&$incr){
+        $incr++;
+    });
+    expect($incr)->toBe(11);
+
+    $colmap = $coll->map(function($item) {
+        return $item+1;
+    });
+    expect($colmap)->toBeInstanceOf(Collection::class);
+    expect($colmap->count())->toBe(11);
+    expect($colmap->first())->toBe(1);
+    expect($colmap->last())->toBe(11);
+
+    $init = 0;
+    $reduce = $coll->reduce(function($item,$carry){
+        return $item + $carry;
+    },$init);
+    expect($reduce)->toBe(55);
+});
+