Bug 632572 - CommonJS test adapter

packages/api-utils/lib/test.js

@@ -0,0 +1,129 @@
+/* vim:ts=2:sts=2:sw=2:
+ * ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (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.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is Jetpack.
+ *
+ * The Initial Developer of the Original Code is Mozilla.
+ * Portions created by the Initial Developer are Copyright (C) 2010
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Irakli Gozalishvili <gozala@mozilla.com> (Original Author)
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+"use strict";
+
+const BaseAssert = require("./test/assert").Assert;
+const { isFunction, isObject } = require("type");
+
+/**
+ * Function takes test `suite` object in CommonJS format and defines all of the
+ * tests from that suite and nested suites in a jetpack format on a given
+ * `target` object. Optionally third argument `prefix` can be passed to prefix
+ * all the test names.
+ */
+function defineTestSuite(target, suite, prefix) {
+  prefix = prefix || "";
+
+  // If suite defines `Assert` that's what `assert` object have to be created
+  // from and passed to a test function (This allows custom assertion functions)
+  // See for details: http://wiki.commonjs.org/wiki/Unit_Testing/1.1
+  let Assert = suite.Assert || BaseAssert;
+
+  // Going through each item in the test suite and wrapping it into a
+  // Jetpack test format.
+  Object.keys(suite).forEach(function(key) {
+
+     // If name starts with test then it's a test function or suite.
+    if (key.indexOf("test") === 0) {
+      let test = suite[key];
+
+      // For each test function so we create a wrapper test function in a
+      // jetpack format and copy that to a `target` exports.
+      if (isFunction(test)) {
+
+        // Since names of the test may match across suites we use full object
+        // path as a name to avoid overriding same function.
+        target[prefix + key] = function(options) {
+
+          // Creating `assert` functions for this test.
+          let assert = Assert(options);
+
+          // If CommonJS test function expects more than one argument
+          // it means that test is async and second argument is a callback
+          // to notify that test is finished.
+          if (1 < test.length) {
+
+            // Letting test runner know that test is executed async and
+            // creating a callback function that CommonJS tests will call
+            // once it's done.
+            options.waitUntilDone();
+            test(assert, function() {
+              options.done();
+            });
+          }
+
+          // Otherwise CommonJS test is synchronous so we call it only with
+          // one argument.
+          else {
+            test(assert);
+          }
+        }
+      }
+
+      // If it's an object then it's a test suite containing test function
+      // and / or nested test suites. In that case we just extend prefix used
+      // and call this function to copy and wrap tests from nested suite.
+      else if (isObject(test)) {
+        test.Assert = test.Assert || Assert;
+        defineTestSuite(target, test, prefix + key + ".");
+      }
+    }
+  });
+}
+
+/**
+ * This function is a CommonJS test runner function, but since Jetpack test
+ * runner and test format is different from CommonJS this function shims given
+ * `exports` with all its tests into a Jetpack test format so that build-in
+ * test runner will be able to run CommonJS test without manual changes.
+ */
+exports.run = function run(exports) {
+
+  // We can't leave old properties on exports since those are test in a CommonJS
+  // format that why we move everything to a new `suite` object.
+  let suite = {};
+  Object.keys(exports).forEach(function(key) {
+    suite[key] = exports[key];
+    delete exports[key];
+  });
+
+  // Now we wrap all the CommonJS tests to a Jetpack format and define
+  // those to a given `exports` object since that where jetpack test runner
+  // will look for them.
+  defineTestSuite(exports, suite);
+};