List grunt tasks from terminal (elastic#43798)

* Add ability to run
$ grunt tasks

* Move conf and task to config per review

package.json

@@ -380,6 +380,7 @@
     "geckodriver": "1.16.2",
     "getopts": "^2.2.4",
     "grunt": "1.0.4",
+    "grunt-available-tasks": "^0.6.3",
     "grunt-cli": "^1.2.0",
     "grunt-contrib-watch": "^1.1.0",
     "grunt-karma": "2.0.0",

tasks/config/availabletasks.js

@@ -0,0 +1,35 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+module.exports = function (grunt) {
+  const config = {
+    availabletasks: {
+      tasks: {
+        options: {
+          filter: 'exclude',
+          tasks: ['availabletasks', 'tasks']
+        }
+      }
+    }
+  };
+  grunt.registerTask('tasks', ['availabletasks']);
+  grunt.config.merge(config);
+
+  return config;
+};

yarn.lock

@@ -14010,6 +14010,14 @@ growly@^1.3.0:
   resolved "https://registry.yarnpkg.com/growly/-/growly-1.3.0.tgz#f10748cbe76af964b7c96c93c6bcc28af120c081"
   integrity sha1-8QdIy+dq+WS3yWyTxrzCivEgwIE=
 
+grunt-available-tasks@^0.6.3:
+  version "0.6.3"
+  resolved "https://registry.yarnpkg.com/grunt-available-tasks/-/grunt-available-tasks-0.6.3.tgz#5be7f6fdda776b80a7b272a21f68bd3050f82260"
+  integrity sha1-W+f2/dp3a4CnsnKiH2i9MFD4ImA=
+  dependencies:
+    chalk "^1.1.1"
+    lodash "^4.10.0"
+
 grunt-babel@^8.0.0:
   version "8.0.0"
   resolved "https://registry.yarnpkg.com/grunt-babel/-/grunt-babel-8.0.0.tgz#92ef63aafadf938c488dc2f926ac9846e0c93d1b"
@@ -18594,7 +18602,7 @@ [email protected], [email protected]:
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.13.tgz#0bdc3a6adc873d2f4e0c4bac285df91b64fc7b93"
   integrity sha512-vm3/XWXfWtRua0FkUyEHBZy8kCPjErNBT9fJx8Zvs+U6zjqPbTUOpkaoum3O5uiA8sm+yNMHXfYkTUHFoMxFNA==
 
-lodash@>4.17.4, lodash@^4.0.0, lodash@^4.0.1, lodash@^4.11.1, lodash@^4.13.1, lodash@^4.14.0, lodash@^4.15.0, lodash@^4.16.4, lodash@^4.17.0, lodash@^4.17.10, lodash@^4.17.11, lodash@^4.17.13, lodash@^4.17.15, lodash@^4.17.2, lodash@^4.17.4, lodash@^4.17.5, lodash@^4.2.0, lodash@^4.2.1, lodash@^4.3.0, lodash@^4.5.0, lodash@^4.6.1, lodash@~4.17.10, lodash@~4.17.5:
+lodash@>4.17.4, lodash@^4.0.0, lodash@^4.0.1, lodash@^4.10.0, lodash@^4.11.1, lodash@^4.13.1, lodash@^4.14.0, lodash@^4.15.0, lodash@^4.16.4, lodash@^4.17.0, lodash@^4.17.10, lodash@^4.17.11, lodash@^4.17.13, lodash@^4.17.15, lodash@^4.17.2, lodash@^4.17.4, lodash@^4.17.5, lodash@^4.2.0, lodash@^4.2.1, lodash@^4.3.0, lodash@^4.5.0, lodash@^4.6.1, lodash@~4.17.10, lodash@~4.17.5:
   version "4.17.15"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.15.tgz#b447f6670a0455bbfeedd11392eff330ea097548"
   integrity sha512-8xOcRHvCjnocdS5cpwXQXVzmmh5e5+saE2QGoeQmbKmRS6J3VQppPOIt0MnmE+4xlZoumy0GPG0D0MVIQbNA1A==