PHPUnit assertion function to check the types of all items in an array

phpunit-assert-contains-only-type.php

<?php>
	/**
	 * Checks if all first-level items in the array are of the given type.
	 *
	 * Example:
	 *
	 *     function test_get_posts_with_no_fields_arg_should_return_array_of_WP_Post_objects() {
	 *         $this-assertContainsOnlyType( 'WP_Post', get_posts() );
	 *     }
	 *
	 * @since 2.1
	 *
	 * @param string $type     Type to check against.
	 * @param array  $actual   Actual array.
	 */
	public function assertContainsOnlyType( $type, $actual ) {
		$standard_types = array(
			'numeric', 'integer', 'int', 'float', 'string', 'boolean', 'bool',
			'null', 'array', 'object', 'resource', 'scalar'
		);


		if ( in_array( $type, $standard_types, true ) ) {
			



	/**
	 * Checks if all items in the array are of the given type.
	 *
	 * @since 2.1
	 *
	 * @param string $type     Type to check against.
	 * @param array  $actual   Actual array.
	 */
	public function assertContainsOnlyType( $type, $actual ) {
		$standard_types = array(
			'numeric', 'integer', 'int', 'float', 'string', 'boolean', 'bool',
			'null', 'array', 'object', 'resource', 'scalar'
		);

		if ( in_array( $type, $standard_types, true ) ) {
			if ( class_exists( '\PHPUnit\Framework\Constraint\IsType' ) ) {
				$constraint = new \PHPUnit\Framework\Constraint\IsType( $type );
			} else {
				$constraint = new \PHPUnit_Framework_Constraint_IsType( $type );
			}
		} else {
			if ( class_exists( '\PHPUnit\Framework\Constraint\IsInstanceOf' ) ) {
				$constraint = new \PHPUnit\Framework\Constraint\IsInstanceOf( $type );
			} else {
				$constraint = new \PHPUnit_Framework_Constraint_IsInstanceOf( $type );
			}
		}

		foreach ( $actual as $item ) {
			if ( class_exists( '\PHPUnit\Framework\Assert' ) ) {
				\PHPUnit\Framework\Assert::assertThat( $item, $constraint );
			} else {
				\PHPUnit_Framework_Assert::assertThat( $item, $constraint );
			}
		}
	}

		foreach ( $actual as $item ) {
			\PHPUnit_Framework_Assert::assertThat( $item, $constraint );
		}
	}

If you only need to check objects type:

self::assertContainsOnlyInstancesOf('Myclass', $array);