New: add update API (fixes #185) (#195)

* Add update function

* Add version getter

* Remove duplicate map call

lib/api.js

@@ -64,6 +64,40 @@ class API {
     })
   }
 
+  /**
+   * Updates an existing installation of the framework
+   * @param {Object} options
+   * @param {string} [options.version=null] Specific version of the framework to install
+   * @param {string} [options.repository] URL to github repo
+   * @param {string} [options.cwd=process.cwd()] Directory to install into
+   * @return {Promise}
+   */
+  async updateFramework ({
+    version = null,
+    repository = ADAPT_FRAMEWORK,
+    cwd = process.cwd(),
+    logger
+  } = {}) {
+    // cache state of plugins, as these will be wiped
+    const plugins = (await new Project({ cwd }).getInstallTargets())
+      .map(p => p.isLocalSource ? p.sourcePath : `${p.name}@${p.requestedVersion}`)
+
+    await this.installFramework({ version, repository, cwd, logger })
+    // restore plugins
+    await this.installPlugins({ plugins, cwd, logger })
+  }
+
+  /**
+   * @param {Object} options
+   * @param {string} [options.cwd=process.cwd()] Directory to install into
+   * @returns {string}
+   */
+  getCurrentFrameworkVersion ({
+    cwd = process.cwd(),
+  } = {}) {
+    return new Project({ cwd }).version
+  }
+
   /**
    * @param {Object} options
    * @param {Object} [options.repository=ADAPT_FRAMEWORK] The github repository url