Block version gating (#14703)

* Add a check to see if required version of gutenberg is available before registering a block

class.jetpack-gutenberg.php

@@ -27,6 +27,11 @@ function jetpack_register_block( $slug, $args = array() ) {
 		$slug = 'jetpack/' . $slug;
 	}
 
+	if ( isset( $args['version_requirements'] )
+		&& ! Jetpack_Gutenberg::is_gutenberg_version_available( $args['version_requirements'], $slug ) ) {
+		return false;
+	}
+
 	// Checking whether block is registered to ensure it isn't registered twice.
 	if ( Jetpack_Gutenberg::is_registered( $slug ) ) {
 		return false;
@@ -89,6 +94,59 @@ class Jetpack_Gutenberg {
 	 */
 	private static $availability = array();
 
+	/**
+	 * Check to see if a minimum version of Gutenberg is available. Because a Gutenberg version is not available in
+	 * php if the Gutenberg plugin is not installed, if we know which minimum WP release has the required version we can
+	 * optionally fall back to that.
+	 *
+	 * @param array  $version_requirements An array containing the required Gutenberg version and, if known, the WordPress version that was released with this minimum version.
+	 * @param string $slug The slug of the block or plugin that has the gutenberg version requirement.
+	 *
+	 * @since 8.3.0
+	 *
+	 * @return boolean True if the version of gutenberg required by the block or plugin is available.
+	 */
+	public static function is_gutenberg_version_available( $version_requirements, $slug ) {
+		global $wp_version;
+
+		// Bail if we don't at least have the gutenberg version requirement, the WP version is optional.
+		if ( empty( $version_requirements['gutenberg'] ) ) {
+			return false;
+		}
+
+		// If running a local dev build of gutenberg plugin GUTENBERG_DEVELOPMENT_MODE is set so assume correct version.
+		if ( defined( 'GUTENBERG_DEVELOPMENT_MODE' ) && GUTENBERG_DEVELOPMENT_MODE ) {
+			return true;
+		}
+
+		$version_available = false;
+
+		// If running a production build of the gutenberg plugin then GUTENBERG_VERSION is set, otherwise if WP version
+		// with required version of Gutenberg is known check that.
+		if ( defined( 'GUTENBERG_VERSION' ) ) {
+			$version_available = version_compare( GUTENBERG_VERSION, $version_requirements['gutenberg'], '>=' );
+		} elseif ( ! empty( $version_requirements['wp'] ) ) {
+			$version_available = version_compare( $wp_version, $version_requirements['wp'], '>=' );
+		}
+
+		if ( ! $version_available ) {
+			self::set_extension_unavailable(
+				$slug,
+				'incorrect_gutenberg_version',
+				array(
+					'required_feature' => $slug,
+					'required_version' => $version_requirements,
+					'current_version'  => array(
+						'wp'        => $wp_version,
+						'gutenberg' => defined( 'GUTENBERG_VERSION' ) ? GUTENBERG_VERSION : null,
+					),
+				)
+			);
+		}
+
+		return $version_available;
+	}
+
 	/**
 	 * Prepend the 'jetpack/' prefix to a block name
 	 *

tests/php/general/test-class.jetpack-gutenberg.php

@@ -149,4 +149,26 @@ function test_get_available_extensions() {
 		$this->assertNotEmpty( $extensions );
 		$this->assertNotContains( 'onion', $extensions );
 	}
+
+	function test_returns_false_if_core_wp_version_less_than_minimum() {
+		$version_gated = Jetpack_Gutenberg::is_gutenberg_version_available(
+			array(
+				'wp'        => '999999',
+				'gutenberg' => '999999',
+			),
+			'gated_block'
+		);
+		$this->assertEquals( false, $version_gated );
+	}
+
+	function test_returns_true_if_core_wp_version_greater_or_equal_to_minimum() {
+		$version_gated = Jetpack_Gutenberg::is_gutenberg_version_available(
+			array(
+				'wp'        => '1',
+				'gutenberg' => '999999',
+			),
+			'ungated_block'
+		);
+		$this->assertEquals( true, $version_gated );
+	}
 }