Tests added.

src/Interfaces/ArraySelectorInterface.php

@@ -21,6 +21,17 @@ interface ArraySelectorInterface
      */
     public function select(ArrayViewInterface $source, ?bool $readonly = null): ArrayViewInterface;
 
+    /**
+     * Checks if the selector is compatible with the given view.
+     *
+     * @template T View elements type.
+     *
+     * @param ArrayViewInterface<T> $view the view to check compatibility with.
+     *
+     * @return bool true if the element is compatible, false otherwise
+     */
+    public function compatibleWith(ArrayViewInterface $view): bool;
+
     /**
      * Return value of the selector.
      *

src/Selectors/IndexListSelector.php

@@ -45,6 +45,22 @@ public function select(ArrayViewInterface $source, ?bool $readonly = null): Arra
         return new ArrayIndexListView($source, $this->value, $readonly ?? $source->isReadonly());
     }
 
+    /**
+     * Checks if the selector is compatible with the given view.
+     *
+     * @template T View elements type.
+     *
+     * @param ArrayViewInterface<T> $view the view to check compatibility with.
+     *
+     * @return bool true if the element is compatible, false otherwise
+     *
+     * {@inheritDoc}
+     */
+    public function compatibleWith(ArrayViewInterface $view): bool
+    {
+        return \count($this->value) === 0 || \max($this->value) < \count($view) && \min($this->value) >= -\count($view);
+    }
+
     /**
      * {@inheritDoc}
      */

src/Selectors/MaskSelector.php

@@ -45,6 +45,22 @@ public function select(ArrayViewInterface $source, ?bool $readonly = null): Arra
         return new ArrayMaskView($source, $this->value, $readonly ?? $source->isReadonly());
     }
 
+    /**
+     * Checks if the selector is compatible with the given view.
+     *
+     * @template T View elements type.
+     *
+     * @param ArrayViewInterface<T> $view the view to check compatibility with.
+     *
+     * @return bool true if the element is compatible, false otherwise
+     *
+     * {@inheritDoc}
+     */
+    public function compatibleWith(ArrayViewInterface $view): bool
+    {
+        return \count($this->value) === \count($view);
+    }
+
     /**
      * {@inheritDoc}
      */

src/Selectors/SliceSelector.php

@@ -42,6 +42,22 @@ public function select(ArrayViewInterface $source, ?bool $readonly = null): Arra
         return new ArraySliceView($source, $this, $readonly ?? $source->isReadonly());
     }
 
+    /**
+     * Checks if the selector is compatible with the given view.
+     *
+     * @template T View elements type.
+     *
+     * @param ArrayViewInterface<T> $view the view to check compatibility with.
+     *
+     * @return bool true if the element is compatible, false otherwise
+     *
+     * {@inheritDoc}
+     */
+    public function compatibleWith(ArrayViewInterface $view): bool
+    {
+        return true;
+    }
+
     /**
      * {@inheritDoc}
      */

src/Traits/ArrayViewAccessTrait.php

@@ -42,7 +42,7 @@ public function offsetExists($offset): bool
         }
 
         if ($offset instanceof ArraySelectorInterface) {
-            return true;
+            return $offset->compatibleWith($this);
         }
 
         return false;

tests/unit/ArrayIndexListView/IssetTest.php

@@ -0,0 +1,149 @@
+<?php
+
+namespace Smoren\ArrayView\Tests\Unit\ArrayIndexListView;
+
+use Smoren\ArrayView\Exceptions\IndexError;
+use Smoren\ArrayView\Selectors\IndexListSelector;
+use Smoren\ArrayView\Views\ArrayView;
+
+class IssetTest extends \Codeception\Test\Unit
+{
+    /**
+     * @dataProvider dataProviderForIssetSingleTrue
+     */
+    public function testIssetSingleTrue(array $source, array $indexes)
+    {
+        $view = ArrayView::toView($source);
+        $subview = $view->subview(new IndexListSelector($indexes));
+
+        $existIndexes = [
+            ...range(0, \count($indexes) - 1),
+            ...range(-1, -\count($indexes)),
+        ];
+
+        foreach ($existIndexes as $index) {
+            $this->assertTrue(isset($subview[$index]), $index);
+        }
+    }
+
+    /**
+     * @dataProvider dataProviderForIssetSingleFalse
+     */
+    public function testIssetSingleFalse(array $source, array $indexes, array $expected)
+    {
+        $view = ArrayView::toView($source);
+        $subview = $view->subview(new IndexListSelector($indexes));
+
+        foreach ($expected as $index) {
+            $this->assertFalse(isset($subview[$index]), $index);
+        }
+    }
+
+    /**
+     * @dataProvider dataProviderForIssetSelectorTrue
+     */
+    public function testIssetSelectorTrue(array $source, array $indexes)
+    {
+        $view = ArrayView::toView($source);
+
+        $this->assertTrue(isset($view[new IndexListSelector($indexes)]));
+
+        $subview = $view->subview(new IndexListSelector($indexes));
+        $this->assertSame(\count($indexes), \count($subview));
+
+        $subview = $view[new IndexListSelector($indexes)];
+        $this->assertSame(\count($indexes), \count($subview));
+    }
+
+    /**
+     * @dataProvider dataProviderForIssetSelectorFalse
+     */
+    public function testIssetSelectorFalse(array $source, array $indexes)
+    {
+        $view = ArrayView::toView($source);
+
+        $this->assertFalse(isset($view[new IndexListSelector($indexes)]));
+
+        $this->expectException(IndexError::class);
+        $_ = $view[new IndexListSelector($indexes)];
+    }
+
+    public function dataProviderForIssetSingleTrue(): array
+    {
+        return [
+            [[1], [0]],
+            [[1], [0, 0]],
+            [[1], [0, 0, 0]],
+            [[1, 2], [0]],
+            [[1, 2], [1]],
+            [[1, 2], [0, 1]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [1, 3, 5, 7]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [7, 5, 3, 1]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [1, 5, 3, 7]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [0, 1, 7, 8]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [1, 1, 5, 5, 3]],
+        ];
+    }
+
+    public function dataProviderForIssetSingleFalse(): array
+    {
+        return [
+            [[], [], [-2, -1, 0, 1, 2]],
+            [[1], [], [-2, -1, 0, 1, 2]],
+            [[1, 2, 3], [], [-2, -1, 0, 1, 2]],
+            [[1], [0], [-3, -2, 1, 2]],
+            [[1], [0, 0], [-5, -4, -3, 2, 3, 4]],
+            [[1], [0, 0, 0], [-6, -5, -4, 3, 4, 5]],
+            [[1, 2], [0], [-3, -2, 1, 2]],
+            [[1, 2], [1], [-3, -2, 1, 2]],
+            [[1, 2], [0, 1], [-5, -4, -3, 2, 3, 4]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [1, 3, 5, 7], [-7, -6, -5, 4, 5, 6]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [7, 5, 3, 1], [-7, -6, -5, 4, 5, 6]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [1, 5, 3, 7], [-7, -6, -5, 4, 5, 6]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [0, 1, 7, 8], [-7, -6, -5, 4, 5, 6]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [1, 1, 5, 5, 3], [-8, -7, -6, 5, 6, 7]],
+        ];
+    }
+
+    public function dataProviderForIssetSelectorTrue(): array
+    {
+        return [
+            [[1], []],
+            [[1], [0]],
+            [[1], [-1]],
+            [[1], [0, 0]],
+            [[1], [0, 0, 0]],
+            [[1, 2], []],
+            [[1, 2], [0]],
+            [[1, 2], [-1, -2]],
+            [[1, 2], [1]],
+            [[1, 2], [0, 1]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], []],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [1, 3, 5, 7]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [7, 5, 3, 1]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [1, 5, 3, 7]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [0, 1, 7, 8]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], []],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [1, 1, 5, 5, 3]],
+        ];
+    }
+
+    public function dataProviderForIssetSelectorFalse(): array
+    {
+        return [
+            [[1], [0, 1]],
+            [[1], [1, -1, -2]],
+            [[1], [0, 1, 0, -1, -2]],
+            [[1], [1, -1]],
+            [[1], [0, 0, -2]],
+            [[1, 2], [2]],
+            [[1, 2], [1, 2]],
+            [[1, 2], [0, 1, 2]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [1, 3, 5, -10]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [9, 5, 3, 1]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [1, 10, 9, 7]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [-10, 1, 7, 10]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [1, 1, 50, 5, 3]],
+        ];
+    }
+}

tests/unit/ArrayIndexListView/ReadTest.php

@@ -0,0 +1,83 @@
+<?php
+
+namespace Smoren\ArrayView\Tests\Unit\ArrayIndexListView;
+
+use Smoren\ArrayView\Selectors\IndexListSelector;
+use Smoren\ArrayView\Selectors\MaskSelector;
+use Smoren\ArrayView\Views\ArrayIndexListView;
+use Smoren\ArrayView\Views\ArrayView;
+
+class ReadTest extends \Codeception\Test\Unit
+{
+    /**
+     * @dataProvider dataProviderForRead
+     */
+    public function testReadByMethod(array $source, array $indexes, array $expected)
+    {
+        $view = ArrayView::toView($source);
+        $subview = $view->subview(new IndexListSelector($indexes));
+
+        $this->assertInstanceOf(ArrayIndexListView::class, $subview);
+
+        $this->assertSame($expected, [...$subview]);
+        $this->assertSame(\count($expected), \count($subview));
+
+        for ($i = 0; $i < \count($subview); ++$i) {
+            $this->assertSame($expected[$i], $subview[$i]);
+        }
+
+        for ($i = 0; $i < \count($view); ++$i) {
+            $this->assertSame($source[$i], $view[$i]);
+        }
+
+        $this->assertSame($source, $view->toArray());
+        $this->assertSame($expected, $subview->toArray());
+
+        $this->assertSame($source, [...$view]);
+        $this->assertSame($expected, [...$subview]);
+    }
+
+    /**
+     * @dataProvider dataProviderForRead
+     */
+    public function testReadByIndex(array $source, array $mask, array $expected)
+    {
+        $view = ArrayView::toView($source);
+        $subArray = $view[new IndexListSelector($mask)];
+
+        $this->assertSame($expected, $subArray);
+        $this->assertSame(\count($expected), \count($subArray));
+
+        for ($i = 0; $i < \count($subArray); ++$i) {
+            $this->assertSame($expected[$i], $subArray[$i]);
+        }
+
+        for ($i = 0; $i < \count($view); ++$i) {
+            $this->assertSame($source[$i], $view[$i]);
+        }
+
+        $this->assertSame($source, $view->toArray());
+        $this->assertSame($source, [...$view]);
+        $this->assertSame($expected, $subArray);
+    }
+
+    public function dataProviderForRead(): array
+    {
+        return [
+            [[], [], []],
+            [[1], [], []],
+            [[1, 2, 3], [], []],
+            [[1], [0], [1]],
+            [[1], [0, 0], [1, 1]],
+            [[1], [0, 0, 0], [1, 1, 1]],
+            [[1, 2], [0], [1]],
+            [[1, 2], [1], [2]],
+            [[1, 2], [0, 1], [1, 2]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [1, 3, 5, 7], [2, 4, 6, 8]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [7, 5, 3, 1], [8, 6, 4, 2]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [1, 5, 3, 7], [2, 6, 4, 8]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [0, 1, 7, 8], [1, 2, 8, 9]],
+            [[1, 2, 3, 4, 5, 6, 7, 8, 9], [1, 1, 5, 5, 3], [2, 2, 6, 6, 4]],
+        ];
+    }
+}