NVDA test method _WaitForSpeech should ignore unrelated speech.

Current, we have a method _WaitForSpeech which blocks on NVDA to speak
exactly the given set of text.

What this CL does is modifies _WaitForSpeech such that it only tests
for the ordered set of given text and ignores text that may have
happened prior to the text we're looking for.

Because of this change, I also renamed the method to _TestForSpeech


Bug: 742592
Change-Id: I37f2ff890a2f8860afac17b0011300d8fd34dd3f
Reviewed-on: https://chromium-review.googlesource.com/599607
Commit-Queue: Doug Turner <dougt@chromium.org>
Reviewed-by: Alice Boxhall <aboxhall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#491881}

tools/accessibility/nvda/nvda_chrome_tests.py

@@ -118,7 +118,7 @@ class NvdaChromeTest(unittest.TestCase):
     self.last_nvda_log_line = 0;
 
     try:
-      self._WaitForSpeech(['Address and search bar edit', 'about:blank'])
+      self._TestForSpeech(['Address and search bar edit', 'about:blank'])
     except:
       self.tearDown()
 
@@ -163,7 +163,16 @@ class NvdaChromeTest(unittest.TestCase):
     self.last_nvda_log_line = len(lines) - 1
     return result
 
-  def _WaitForSpeech(self, expected):
+  def _ArrayInArray(self, lines, expected):
+    positions = len(lines) - len(expected) + 1;
+    if (positions >= 0):
+      # loop through the number of positions that the subset can hold
+      for index in range(positions):
+        if (lines[index : index + len(expected)] == expected):
+          return True
+    return False
+
+  def _TestForSpeech(self, expected):
     """Block until the last speech in NVDA's log file is the given string(s).
 
     Repeatedly parses the log file until the last speech line(s) in the
@@ -172,26 +181,21 @@ class NvdaChromeTest(unittest.TestCase):
     Args:
       expected: string or a list of string - only succeeds if these are the last
         strings spoken, in order.
-
-    Returns when those strings are spoken, or throws an error if it times out
-      waiting for those strings.
     """
     if type(expected) is type(''):
       expected = [expected]
     start_time = time.time()
     while True:
       lines = self._GetSpeechFromNvdaLogFile()
-      if (lines[-len(expected):] == expected):
-        break
+
+      if self._ArrayInArray(lines, expected):
+        return True
 
       if time.time() - start_time >= WAIT_FOR_SPEECH_TIMEOUT_SECS:
-        print('** Speech from NVDA so far:')
-        for line in lines:
-          print('"%s"' % line)
-        print('** Was waiting for:')
-        for line in expected:
-          print('"%s"' % line)
-        raise Exception('Timed out')
+        self.fail("Test for expected speech failed.\n\nExpected:\n" +
+          str(expected) +
+          ".\n\nActual:\n" + str(lines));
+        return False
       time.sleep(0.1)
 
   #
@@ -201,34 +205,34 @@ class NvdaChromeTest(unittest.TestCase):
   def testTypingInOmnibox(self):
     # Ctrl+A: Select all.
     self._pywinauto_window.TypeKeys('^A')
-    self._WaitForSpeech('selecting about:blank')
+    self._TestForSpeech('selecting about:blank')
 
     # Type three characters.
     self._pywinauto_window.TypeKeys('xyz')
-    self._WaitForSpeech(['x', 'y', 'z'])
+    self._TestForSpeech(['x', 'y', 'z'])
 
     # Arrow back over two characters.
     self._pywinauto_window.TypeKeys('{LEFT}')
-    self._WaitForSpeech(['z', 'z', 'unselecting'])
+    self._TestForSpeech(['z', 'z', 'unselecting'])
 
     self._pywinauto_window.TypeKeys('{LEFT}')
-    self._WaitForSpeech('y')
+    self._TestForSpeech('y')
 
   def testFocusToolbarButton(self):
     # Alt+Shift+T.
     self._pywinauto_window.TypeKeys('%+T')
-    self._WaitForSpeech('Reload button Reload this page')
+    self._TestForSpeech('Reload button Reload this page')
 
   def testReadAllOnPageLoad(self):
     # Ctrl+A: Select all
     self._pywinauto_window.TypeKeys('^A')
-    self._WaitForSpeech('selecting about:blank')
+    self._TestForSpeech('selecting about:blank')
 
     # Load data url.
     self._pywinauto_window.TypeKeys('data:text/html,Hello<p>World.')
-    self._WaitForSpeech('dot')
+    self._TestForSpeech('dot')
     self._pywinauto_window.TypeKeys('{ENTER}')
-    self._WaitForSpeech(
+    self._TestForSpeech(
         ['document',
          'Hello',
          'World.'])