diff --git a/framework/test/exceptions_test.py b/framework/test/exceptions_test.py
new file mode 100644
index 0000000..8fe2295
--- /dev/null
+++ b/framework/test/exceptions_test.py
@@ -0,0 +1,64 @@
+# Copyright 2020 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+"""Unittest for the exceptions module."""
+
+from __future__ import print_function
+from __future__ import division
+from __future__ import absolute_import
+
+import unittest
+
+from framework import exceptions
+from framework import permissions
+
+
+class ErrorsManagerTest(unittest.TestCase):
+
+  def testRaiseIfErrors_Errors(self):
+    """We raise the given exception if there are errors."""
+    err_aggregator = exceptions.ErrorAggregator(exceptions.InputException)
+
+    err_aggregator.AddErrorMessage('The chickens are missing.')
+    err_aggregator.AddErrorMessage('The foxes are free.')
+    with self.assertRaisesRegexp(
+        exceptions.InputException,
+        'The chickens are missing.\nThe foxes are free.'):
+      err_aggregator.RaiseIfErrors()
+
+  def testErrorsManager_NoErrors(self):
+    """ We don't raise exceptions if there are not errors. """
+    err_aggregator = exceptions.ErrorAggregator(exceptions.InputException)
+    err_aggregator.RaiseIfErrors()
+
+  def testWithinContext_ExceptionPassedIn(self):
+    """We do not suppress exceptions raised within wrapped code."""
+
+    with self.assertRaisesRegexp(exceptions.InputException,
+                                 'We should raise this'):
+      with exceptions.ErrorAggregator(exceptions.InputException) as errors:
+        errors.AddErrorMessage('We should ignore this error.')
+        raise exceptions.InputException('We should raise this')
+
+  def testWithinContext_NoExceptionPassedIn(self):
+    """We raise an exception for any errors if no exceptions are passed in."""
+    with self.assertRaisesRegexp(exceptions.InputException,
+                                 'We can raise this now.'):
+      with exceptions.ErrorAggregator(exceptions.InputException) as errors:
+        errors.AddErrorMessage('We can raise this now.')
+        return True
+
+  def testAddErrorMessage(self):
+    """We properly handle string formatting when needed."""
+    err_aggregator = exceptions.ErrorAggregator(exceptions.InputException)
+    err_aggregator.AddErrorMessage('No args')
+    err_aggregator.AddErrorMessage('No args2', 'unused', unused2=1)
+    err_aggregator.AddErrorMessage('{}', 'One arg')
+    err_aggregator.AddErrorMessage('{}, {two}', '1', two='2')
+
+    # Verify exceptions formatting a message don't clear the earlier messages.
+    with self.assertRaises(IndexError):
+      err_aggregator.AddErrorMessage('{}')
+
+    expected = ['No args', 'No args2', 'One arg', '1, 2']
+    self.assertEqual(err_aggregator.error_messages, expected)