Bug 1275983 - adding relations caching tests. r=eeejay

MozReview-Commit-ID: 3cisZF54kp0

accessible/tests/browser/.eslintrc

@@ -14,6 +14,7 @@
     "testName": true,
     "testDescr": true,
     "testStates": true,
+    "testRelation": true,
     "testAccessibleTree": true,
     "isAccessible": true,
     "getAccessibleDOMNodeID": true,

accessible/tests/browser/browser.ini

@@ -17,6 +17,7 @@ support-files =
 [browser_caching_description.js]
 [browser_caching_name.js]
 skip-if = e10s
+[browser_caching_relations.js]
 [browser_caching_states.js]
 
 # Events tests

accessible/tests/browser/browser_caching_relations.js

@@ -0,0 +1,86 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+'use strict';
+
+/* global RELATION_LABELLED_BY, RELATION_LABEL_FOR, RELATION_DESCRIBED_BY,
+          RELATION_DESCRIPTION_FOR, RELATION_CONTROLLER_FOR,
+          RELATION_CONTROLLED_BY, RELATION_FLOWS_TO, RELATION_FLOWS_FROM */
+
+loadScripts({ name: 'relations.js', dir: MOCHITESTS_DIR });
+
+/**
+ * A test specification that has the following format:
+ * [
+ *   attr                 relevant aria attribute
+ *   hostRelation         corresponding host relation type
+ *   dependantRelation    corresponding dependant relation type
+ * ]
+ */
+const attrRelationsSpec = [
+  ['aria-labelledby', RELATION_LABELLED_BY, RELATION_LABEL_FOR],
+  ['aria-describedby', RELATION_DESCRIBED_BY, RELATION_DESCRIPTION_FOR],
+  ['aria-controls', RELATION_CONTROLLER_FOR, RELATION_CONTROLLED_BY],
+  ['aria-flowto', RELATION_FLOWS_TO, RELATION_FLOWS_FROM]
+];
+
+function* testRelated(browser, accDoc, attr, hostRelation, dependantRelation) {
+  let host = findAccessibleChildByID(accDoc, 'host');
+  let dependant1 = findAccessibleChildByID(accDoc, 'dependant1');
+  let dependant2 = findAccessibleChildByID(accDoc, 'dependant2');
+
+  /**
+   * Test data has the format of:
+   * {
+   *   desc      {String}   description for better logging
+   *   attrs     {?Array}   an optional list of attributes to update
+   *   expected  {Array}    expected relation values for dependant1, dependant2
+   *                        and host respectively.
+   * }
+   */
+  const tests = [{
+    desc: 'No attribute',
+    expected: [ null, null, null ]
+  }, {
+    desc: 'Set attribute',
+    attrs: [{ key: attr, value: 'dependant1' }],
+    expected: [ host, null, dependant1 ]
+  }, {
+    desc: 'Change attribute',
+    attrs: [{ key: attr, value: 'dependant2' }],
+    expected: [ null, host, dependant2 ]
+  }, {
+    desc: 'Remove attribute',
+    attrs: [{ key: attr }],
+    expected: [ null, null, null ]
+  }];
+
+  for (let { desc, attrs, expected } of tests) {
+    info(desc);
+
+    if (attrs) {
+      for (let { key, value } of attrs) {
+        yield invokeSetAttribute(browser, 'host', key, value);
+      }
+    }
+
+    testRelation(dependant1, dependantRelation, expected[0]);
+    testRelation(dependant2, dependantRelation, expected[1]);
+    testRelation(host, hostRelation, expected[2]);
+  }
+}
+
+/**
+ * Test caching of relations between accessible objects.
+ */
+addAccessibleTask(`
+  <div id="dependant1">label</div>
+  <div id="dependant2">label2</div>
+  <div role="checkbox" id="host"></div>`,
+  function* (browser, accDoc) {
+    for (let spec of attrRelationsSpec) {
+      yield testRelated(browser, accDoc, ...spec);
+    }
+  }
+);