Package the plugin for developer use

tests/test-plugin-instantiation.php

@@ -0,0 +1,65 @@
+<?php
+
+/**
+ * Class WP_Test_Fields_Plugin_Instantiation
+ *
+ * @uses PHPUnit_Framework_TestCase
+ */
+class WP_Test_Fields_Plugin_Instantiation extends WP_UnitTestCase {
+
+	// TODO deal with https://make.wordpress.org/plugins/2016/03/01/please-do-not-submit-frameworks/
+
+	// print_r(get_class_methods($this));
+	// die;
+
+	// Make sure that when the plugin loads (via `plugins_loaded`) it starts 
+	// with the correct version number.
+	public function test_begins_with_currect_version() {
+		$VERSION = '0.1.0';
+		$this->assertEquals( WP_FIELDS_API_PLUGIN_VERSION, $VERSION );
+	}
+
+	// test that multiple versions (no matter who starts them) defer to newest
+	public function test_defers_to_latest_version() {
+		// Try including the plugin with differing versions
+		$LOW_VERSION = '1.0.0';
+		$HIGH_VERSION = '2.0.0';
+		WP_Fields_API_v_0_1_0::_debug_force_initialize( $LOW_VERSION );
+		WP_Fields_API_v_0_1_0::_debug_force_initialize( $HIGH_VERSION );
+		do_action( 'plugins_loaded' );
+
+		// Verify that the newest version loads
+		$this->assertEquals( WP_FIELDS_API_PLUGIN_VERSION, $HIGH_VERSION);
+	}
+
+	// test that warnings appear when multiple versions are installed
+	public function test_warns_about_dependency_hell() {
+		// As before, include multiple versions
+		$LOW_VERSION = '1.0.0';
+		$MIDDLE_VERSION = '1.5.0';
+		$HIGH_VERSION = '2.0.0';
+		// _wp_fields_api_include( $LOW_VERSION );
+		// _wp_fields_api_include( $HIGH_VERSION );
+		// _wp_fields_api_include( $MIDDLE_VERSION );
+		WP_Fields_API_v_0_1_0::_debug_force_initialize( $LOW_VERSION, 9999 );
+		WP_Fields_API_v_0_1_0::_debug_force_initialize( $HIGH_VERSION, 9997 );
+		WP_Fields_API_v_0_1_0::_debug_force_initialize( $MIDDLE_VERSION, 9998 );
+
+		// Verify that some sort of warning is emitted.
+		ob_start();
+		do_action( 'plugins_loaded' );
+		do_action( 'admin_notices' );
+		$output = ob_get_contents();
+		$this->assertRegExp("/A plugin is trying to include an older version\s+\($LOW_VERSION <= $HIGH_VERSION\)\s+of the <strong>WP Fields API<\/strong>./m", $output);
+		$this->assertRegExp("/A plugin is trying to include an older version\s+\($MIDDLE_VERSION <= $HIGH_VERSION\)\s+of the <strong>WP Fields API<\/strong>./m", $output);
+		ob_end_clean();
+	}
+
+	public function test_can_multiple_include_file() {
+		include __DIR__ . "/../wordpress-fields-api.php";
+		$this->assertTrue( true ); // Pass this test if include was successful.
+	}
+
+	// test disabling builtin form override
+	public function test_can_disable_builtin_form_override() {}
+}