Fix PHP notice that showed when orderby query parameter was an array (With Unit tests)

[Rajinsharwar]

This is a followup to the https://github.com/WordPress/wordpress-develop/pull/5404, with unit tests.

Trac ticket: https://core.trac.wordpress.org/ticket/59494

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[swissspidy]

Using wp_remote_* is not really the right approach here. If you want to test the frontend output like this, you would write an e2e test. However, this change here does not really warrant an e2e test. A simple unit test that tests the method is good enough. Doing an HTTP call is not really a unit test.

Look at the other unit tests in tests/phpunit/tests/admin/wpListTable.php and how they're written.

You'll want a simple test that calls the search_box() method and verifies the output is as expected.

The structure could look like this:

	/**
	 * Tests that `WP_List_Table::search_box()` supports multiple orderby fields.
	 *
	 * @ticket 59494
	 *
	 * @covers WP_List_Table::search_box
	 */
	public function test_search_box_supports_multiple_orderby() {
		$_REQUEST['s'] = 'search term';

		$output = get_echo( array( $this->list_table, 'search_box' ), array( 'foo', 'bar' ) );

		$this->assertStringContainsString( 'Write your expected string here', $output );
	}

[Rajinsharwar]

Thank you so much @swissspidy. I was specifically looking for a function like get_echo(), which I was unaware of its existence. If you can take a look at my changed tests, please. 🙂. Thanks again!

[Rajinsharwar]

Thanks for your suggestion @peterwilsoncc. I have added another test for the single orderby. Let me know if it fits right.

[Rajinsharwar]

@peterwilsoncc I see. I have committed to the changes. Also, I kept the test for one element array as well. Let me know if this looks good to you. :)

[peterwilsoncc]

Committed in r58379 / https://github.com/WordPress/wordpress-develop/commit/8cd24bc12c7ac3c588ccbf549b1df42884181fe0