Bug 1733514 part 5: Add initial tests for a11y text caching. r=eeejay

Differential Revision: https://phabricator.services.mozilla.com/D128035

accessible/tests/browser/e10s/browser.ini

@@ -20,6 +20,7 @@ support-files =
 skip-if = (os == "linux" && bits == 64) || (debug && os == "mac") || (debug && os == "win") #Bug 1388256
 [browser_caching_relations.js]
 [browser_caching_states.js]
+[browser_caching_text.js]
 [browser_caching_value.js]
 [browser_caching_uniqueid.js]
 [browser_caching_interfaces.js]

accessible/tests/browser/e10s/browser_caching_text.js

@@ -0,0 +1,79 @@
+/* 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";
+
+/* import-globals-from ../../mochitest/text.js */
+loadScripts({ name: "text.js", dir: MOCHITESTS_DIR });
+
+const isCacheEnabled = Services.prefs.getBoolPref(
+  "accessibility.cache.enabled",
+  false
+);
+
+/**
+ * Test line and word offsets for various cases for both local and remote
+ * Accessibles. There is more extensive coverage in ../../mochitest/text. These
+ * tests don't need to duplicate all of that, since much of the underlying code
+ * is unified. They should ensure that the cache works as expected and that
+ * there is consistency between local and remote.
+ */
+addAccessibleTask(
+  `
+<p id="br">ab cd<br>ef gh</p>
+<pre id="pre">ab cd
+ef gh</pre>
+<p id="linksStartEnd"><a href="https://example.com/">a</a>b<a href="https://example.com/">c</a></p>
+<p id="linksBreaking">a<a href="https://example.com/">b<br>c</a>d</p>
+  `,
+  async function(browser, docAcc) {
+    for (const id of ["br", "pre"]) {
+      const acc = findAccessibleChildByID(docAcc, id);
+      if (!isCacheEnabled && AppConstants.platform == "win") {
+        todo(
+          false,
+          "Cache disabled, so RemoteAccessible doesn't support CharacterCount on Windows"
+        );
+      } else {
+        testCharacterCount([acc], 11);
+      }
+      testTextAtOffset(acc, BOUNDARY_LINE_START, [
+        [0, 5, "ab cd\n", 0, 6],
+        [6, 11, "ef gh", 6, 11],
+      ]);
+      testTextAtOffset(acc, BOUNDARY_WORD_START, [
+        [0, 2, "ab ", 0, 3],
+        [3, 5, "cd\n", 3, 6],
+        [6, 8, "ef ", 6, 9],
+        [9, 11, "gh", 9, 11],
+      ]);
+    }
+    const linksStartEnd = findAccessibleChildByID(docAcc, "linksStartEnd");
+    testTextAtOffset(linksStartEnd, BOUNDARY_LINE_START, [
+      [0, 3, `${kEmbedChar}b${kEmbedChar}`, 0, 3],
+    ]);
+    testTextAtOffset(linksStartEnd, BOUNDARY_WORD_START, [
+      [0, 3, `${kEmbedChar}b${kEmbedChar}`, 0, 3],
+    ]);
+    const linksBreaking = findAccessibleChildByID(docAcc, "linksBreaking");
+    testTextAtOffset(linksBreaking, BOUNDARY_LINE_START, [
+      [0, 0, `a${kEmbedChar}`, 0, 2],
+      [1, 1, `a${kEmbedChar}d`, 0, 3],
+      [2, 3, `${kEmbedChar}d`, 1, 3],
+    ]);
+    if (isCacheEnabled) {
+      testTextAtOffset(linksBreaking, BOUNDARY_WORD_START, [
+        [0, 0, `a${kEmbedChar}`, 0, 2],
+        [1, 1, `a${kEmbedChar}d`, 0, 3],
+        [2, 3, `${kEmbedChar}d`, 1, 3],
+      ]);
+    } else {
+      todo(
+        false,
+        "TextLeafPoint disabled, so word boundaries are incorrect for linksBreaking"
+      );
+    }
+  },
+  { chrome: true, topLevel: true, iframe: true, remoteIframe: true }
+);