Override default updates with GitHub release updater

functions.php

@@ -1,6 +1,7 @@
 <?php
 
 require( dirname( __FILE__ ) . '/inc/tags.php' );
+require( dirname( __FILE__ ) . '/inc/updater.php' );
 
 /**
  * Returns the current version of the theme.

inc/updater.php

@@ -0,0 +1,76 @@
+<?php
+
+/**
+ * Prevent Dones from being considered in theme update checks.
+ *
+ * @param  array  $r   An array of HTTP request arguments.
+ * @param  string $url The request URL.
+ * @return array  $r   An array of HTTP request arguments.
+ */
+function dones_exclude_from_update( $r, $url ) {
+	$normalized_url = set_url_scheme( $url, 'http' );
+	if ( 0 === strpos( $normalized_url, 'http://api.wordpress.org/themes/update-check' ) ) {
+		$themes = json_decode( $r['body']['themes'], true );
+		unset( $themes['themes']['dones'] );
+		$r['body']['themes'] = json_encode( $themes );
+	}
+
+	return $r;
+}
+add_filter( 'http_request_args', 'dones_exclude_from_update', 10, 2 );
+
+/**
+ * Performs an update check for the latest version of the theme, returning a
+ * modified theme updates transient with result.
+ *
+ * @param  object $value Value of theme updates transient
+ * @return object $value Modified value of theme updates transient
+ */
+function dones_check_for_update( $value ) {
+	// Bypass update check while installing
+	if ( defined( 'WP_INSTALLING' ) ) {
+		return $value;
+	}
+
+	// Fetch latest version
+	$response = wp_remote_get( 'https://api.github.com/repos/aduth/dones/releases/latest' );
+	if ( is_wp_error( $response ) || ! is_array( $response ) ) {
+		return $value;
+	}
+
+	// Skip if same version
+	$release = json_decode( $response['body'], true );
+	$version = $release['tag_name'];
+	$theme = wp_get_theme();
+	if ( $theme->get( 'Version' ) === $version ) {
+		return $value;
+	}
+
+	// Find pre-built release zip URL, or bail
+	foreach ( $release['assets'] as $asset ) {
+		if ( 'dones.zip' === $asset['name'] ) {
+			$url = $asset['browser_download_url'];
+			break;
+		}
+	}
+
+	if ( ! isset( $url ) ) {
+		return $value;
+	}
+
+	// Initialize pending updates
+	if ( ! isset( $value->response ) ) {
+		$value->response = array();
+	}
+
+	// Assign update
+	$value->response['dones'] = array(
+		'theme'       => 'dones',
+		'new_version' => $version,
+		'url'         => $theme->get( 'ThemeURI' ),
+		'package'     => $url
+	);
+
+	return $value;
+}
+add_action( 'pre_set_site_transient_update_themes', 'dones_check_for_update' );