Add types check to page_set_smoke_test

tools/telemetry/telemetry/unittest/page_set_smoke_test.py

Index: tools/telemetry/telemetry/unittest/page_set_smoke_test.py
diff --git a/tools/telemetry/telemetry/unittest/page_set_smoke_test.py b/tools/telemetry/telemetry/unittest/page_set_smoke_test.py
index 4c7599de7d49eb1b6a4cdd8beeb2ee9517b41c9e..b5e22aed033d60324a8fdbf826379e87cb193fc7 100644
--- a/tools/telemetry/telemetry/unittest/page_set_smoke_test.py
+++ b/tools/telemetry/telemetry/unittest/page_set_smoke_test.py
@@ -15,6 +15,7 @@ from telemetry.page import page_set_archive_info
 class PageSetSmokeTest(unittest.TestCase):
 
   def CheckArchive(self, page_set):
+    """Verify that all URLs of pages in page_set have an associated archive. """
     # TODO: Eventually these should be fatal.
     if not page_set.archive_data_file:
       logging.warning('Skipping %s: no archive data file', page_set.file_path)
@@ -38,6 +39,7 @@ class PageSetSmokeTest(unittest.TestCase):
                           page.url, page_set.archive_data_file))
 
   def CheckCredentials(self, page_set):
+    """Verify that all pages in page_set use proper credentials"""
     credentials = browser_credentials.BrowserCredentials()
     if page_set.credentials_path:
       credentials.credentials_path = (
@@ -51,14 +53,58 @@ class PageSetSmokeTest(unittest.TestCase):
         except browser_credentials.CredentialsError:
           self.fail(fail_message)
 
+  def CheckTypes(self, page_set):
+    """Verify that page_set and its page's base attributes have the right types.
+    """
+    self.CheckTypesOfPageSetBasicAttributes(page_set)
+    for page in page_set.pages:
+      self.CheckTypesOfPageBasicAttributes(page)
+
+  def CheckTypesOfPageSetBasicAttributes(self, page_set):
+    if page_set.file_path is not None:
+      self.assertTrue(
+          isinstance(page_set.file_path, str),
+          msg='page_set %\'s file_path must have type string')
+
+    self.assertTrue(
+        isinstance(page_set.description, str),
+        msg='page_set\'s description must have type string')
+
+    self.assertTrue(
+        isinstance(page_set.archive_data_file, str),
+        msg='page_set\'s archive_data_file path must have type string')
+
+    if page_set.user_agent_type is not None:
+      self.assertTrue(
+          isinstance(page_set.user_agent_type, str),
+          msg='page_set\'s user_agent_type must have type string')
+
+    self.assertTrue(
+        isinstance(page_set.make_javascript_deterministic, bool),
+        msg='page_set\'s make_javascript_deterministic must have type bool')
+
+    self.assertTrue(
+        isinstance(page_set.startup_url, str),
+        msg='page_set\'s startup_url must have type string')
+
+  def CheckTypesOfPageBasicAttributes(self, page):
+    self.assertTrue(
+       isinstance(page.url, str),
+       msg='page %s \'s url must have type string' % page.display_name)
+    self.assertTrue(
+       isinstance(page.page_set, page_set_module.PageSet),
+       msg='page %s \'s page_set must be an instance of '
+       'telemetry.page.page_set.PageSet' % page.display_name)
+    self.assertTrue(
+       isinstance(page.name, str),
+       msg='page %s \'s name field must have type string' % page.display_name)
+
   def RunSmokeTest(self, page_sets_dir):
     """Run smoke test on all page sets in page_sets_dir.
 
     Subclass of PageSetSmokeTest is supposed to call this in some test
     method to run smoke test.
     """
-    # Instantiate all page sets and verify that all URLs have an associated
-    # archive.
     page_sets = discover.GetAllPageSetFilenames(page_sets_dir)
 
     for page_set_path in page_sets:
@@ -66,3 +112,4 @@ class PageSetSmokeTest(unittest.TestCase):
       logging.info('Testing %s', page_set.file_path)
       self.CheckArchive(page_set)
       self.CheckCredentials(page_set)
+      self.CheckTypes(page_set)