diff --git a/.travis.yml b/.travis.yml
index c9c8e275..933ff9c7 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -10,45 +10,28 @@ env:
     - PATH="$PYENV_ROOT/bin:$PATH"
     - PIP_CACHE_DIR="$HOME/.cache/pip"  # unify pip cache location for all platforms
 stages:
-#  - check
-#  - test
+  - test
   - build
-# Travis doesn't support testing python on Mac yet, so we need
-# to workaround it by installing it directly with brew.
-#
-# Note that we specify language as ruby-2.4.3 to help us satisfy
-# fpm dependencies, as travis runs el capitan with an old ruby
-# version, that causes fpm to crash.
-#
 # Each job will use the previous job's `stage` tag if not specified.
 jobs:
   include:
-  # patch formatting checks
-#  - name: "Check patch formatting"
-#    stage: check
-#    os: linux
-#    language: python
-#    python: 3.7
-#    before_install:
-#    install:
-#    script: ./scripts/ci/check_patch.sh
   # test jobs
-#  - name: "3.7 on Windows"
-#    stage: test
-#    os: windows           # Windows 10.0.17134 N/A Build 17134
-#    language: shell       # 'language: python' is an error on Travis CI Windows
-#  - name: "3.5 on Linux"
-#    language: python
-#    python: 3.5
-#  - name: "3.6 on Linux"
-#    language: python
-#    python: 3.6
-#  - name: "3.7 on Linux"
-#    language: python
-#    python: 3.7
-#  - name: "3.7 on Mac"
-#    os: osx
-#    osx_image: xcode11.3
+  - name: "3.7 on Windows"
+    stage: test
+    os: windows
+    language: shell
+  - name: "3.5 on Linux"
+    language: python
+    python: 3.5
+  - name: "3.6 on Linux"
+    language: python
+    python: 3.6
+  - name: "3.7 on Linux"
+    language: python
+    python: 3.7
+  - name: "3.7 on Mac"
+    os: osx
+    osx_image: xcode11.3
   # build jobs
   - name: "Pypi pkgs"
     if: tag is present
diff --git a/pydrive2/auth.py b/pydrive2/auth.py
index c613ef7b..d4948cd3 100644
--- a/pydrive2/auth.py
+++ b/pydrive2/auth.py
@@ -52,7 +52,7 @@ def _decorated(self, *args, **kwargs):
       self.auth = GoogleAuth()
     # Re-create access token if it expired.
     if self.auth.access_token_expired:
-      if getattr(self, 'auth_method', False) == 'service':
+      if getattr(self.auth, 'auth_method', False) == 'service':
         self.auth.ServiceAuth()
       else:
         self.auth.LocalWebserverAuth()
@@ -93,14 +93,9 @@ def _decorated(self, *args, **kwargs):
       decoratee(self, *args, **kwargs)
       self.Authorize()
       dirty = True
-    else:
-      if self.access_token_expired:
-        if self.credentials.refresh_token is not None:
-          self.Refresh()
-        else:
-          decoratee(self, *args, **kwargs)
-          self.Authorize()
-        dirty = True
+    elif self.access_token_expired:
+      self.Refresh()
+      dirty = True
     if dirty and save_credentials:
       self.SaveCredentials()
   return _decorated
@@ -472,7 +467,7 @@ def Refresh(self):
     """
     if self.credentials is None:
       raise RefreshError('No credential to refresh.')
-    if self.credentials.refresh_token is None:
+    if self.credentials.refresh_token is None and self.auth_method != 'service':
       raise RefreshError('No refresh_token found.'
                          'Please set access_type of OAuth to offline.')
     if self.http is None:
@@ -521,10 +516,11 @@ def Authorize(self):
 
     :raises: AuthenticationError
     """
-    if self.http is None:
-      self.http = httplib2.Http(timeout=self.http_timeout)
     if self.access_token_expired:
       raise AuthenticationError('No valid credentials provided to authorize')
+
+    if self.http is None:
+      self.http = httplib2.Http(timeout=self.http_timeout)
     self.http = self.credentials.authorize(self.http)
     self.service = build('drive', 'v2', http=self.http, cache_discovery=False)
 
diff --git a/pydrive2/files.py b/pydrive2/files.py
index 06cd4c0a..dff8eb17 100644
--- a/pydrive2/files.py
+++ b/pydrive2/files.py
@@ -560,7 +560,7 @@ def _DeletePermission(self, permission_id):
       if 'permissions' in self and 'permissions' in self.metadata:
         permissions = self['permissions']
         is_not_current_permission = lambda per: per['id'] == permission_id
-        permissions = filter(is_not_current_permission, permissions)
+        permissions = list(filter(is_not_current_permission, permissions))
         self['permissions'] = permissions
         self.metadata['permissions'] = permissions
       return True
diff --git a/pydrive2/test/settings/default.yaml b/pydrive2/test/settings/default.yaml
index 0697513f..712cdb63 100644
--- a/pydrive2/test/settings/default.yaml
+++ b/pydrive2/test/settings/default.yaml
@@ -1,9 +1,12 @@
-client_config_backend: 'file'
-client_config_file: 'configs/client_secrets.json'
+client_config_backend: file
+service_config:
+  client_service_email: your-service-account-email
+  client_pkcs12_file_path: your-file-path.p12
+  client_user_email:
 
 save_credentials: True
-save_credentials_backend: 'file'
-save_credentials_file: 'credentials/1.dat'
+save_credentials_backend: file
+save_credentials_file: credentials/default.dat
 
 oauth_scope:
-  - 'https://www.googleapis.com/auth/drive'
+  - https://www.googleapis.com/auth/drive
diff --git a/pydrive2/test/settings/test1.yaml b/pydrive2/test/settings/test_oauth_default.yaml
similarity index 100%
rename from pydrive2/test/settings/test1.yaml
rename to pydrive2/test/settings/test_oauth_default.yaml
diff --git a/pydrive2/test/settings/test_oauth_test_01.yaml b/pydrive2/test/settings/test_oauth_test_01.yaml
new file mode 100644
index 00000000..0697513f
--- /dev/null
+++ b/pydrive2/test/settings/test_oauth_test_01.yaml
@@ -0,0 +1,9 @@
+client_config_backend: 'file'
+client_config_file: 'configs/client_secrets.json'
+
+save_credentials: True
+save_credentials_backend: 'file'
+save_credentials_file: 'credentials/1.dat'
+
+oauth_scope:
+  - 'https://www.googleapis.com/auth/drive'
diff --git a/pydrive2/test/settings/test2.yaml b/pydrive2/test/settings/test_oauth_test_02.yaml
similarity index 100%
rename from pydrive2/test/settings/test2.yaml
rename to pydrive2/test/settings/test_oauth_test_02.yaml
diff --git a/pydrive2/test/settings/test3.yaml b/pydrive2/test/settings/test_oauth_test_03.yaml
similarity index 100%
rename from pydrive2/test/settings/test3.yaml
rename to pydrive2/test/settings/test_oauth_test_03.yaml
diff --git a/pydrive2/test/settings/test4.yaml b/pydrive2/test/settings/test_oauth_test_04.yaml
similarity index 100%
rename from pydrive2/test/settings/test4.yaml
rename to pydrive2/test/settings/test_oauth_test_04.yaml
diff --git a/pydrive2/test/settings/test5.yaml b/pydrive2/test/settings/test_oauth_test_05.yaml
similarity index 100%
rename from pydrive2/test/settings/test5.yaml
rename to pydrive2/test/settings/test_oauth_test_05.yaml
diff --git a/pydrive2/test/settings/test6.yaml b/pydrive2/test/settings/test_oauth_test_06.yaml
similarity index 87%
rename from pydrive2/test/settings/test6.yaml
rename to pydrive2/test/settings/test_oauth_test_06.yaml
index 19d55bbb..6d919958 100644
--- a/pydrive2/test/settings/test6.yaml
+++ b/pydrive2/test/settings/test_oauth_test_06.yaml
@@ -6,7 +6,7 @@ service_config:
 
 save_credentials: True
 save_credentials_backend: 'file'
-save_credentials_file: 'credentials/5.dat'
+save_credentials_file: 'credentials/6.dat'
 
 oauth_scope:
   - "https://www.googleapis.com/auth/drive"
diff --git a/pydrive2/test/test_apiattr.py b/pydrive2/test/test_apiattr.py
index a1632f00..5950ada4 100644
--- a/pydrive2/test/test_apiattr.py
+++ b/pydrive2/test/test_apiattr.py
@@ -1,21 +1,23 @@
 import unittest
+import pytest
 
 from pydrive2.auth import GoogleAuth
 from pydrive2.drive import GoogleDrive
+from pydrive2.test.test_util import pydrive_retry, setup_credentials
+
 
 class ApiAttributeTest(unittest.TestCase):
     """Test ApiAttr functions.
     """
-    ga = GoogleAuth('settings/test1.yaml')
-    ga.LocalWebserverAuth()
-    first_file = 'a.png'
-    second_file = 'b.png'
+
+    @classmethod
+    def setup_class(cls):
+        setup_credentials()
 
     def test_UpdateMetadataNotInfinitelyNesting(self):
         # Verify 'metadata' field present.
         self.assertTrue(self.file1.metadata is not None)
-        self.file1.UpdateMetadata()
-        self.file1.UpdateMetadata()
+        pydrive_retry(self.file1.UpdateMetadata)
 
         # Verify 'metadata' field still present.
         self.assertTrue(self.file1.metadata is not None)
@@ -23,12 +25,14 @@ def test_UpdateMetadataNotInfinitelyNesting(self):
         self.assertTrue('metadata' not in self.file1.metadata)
 
     def setUp(self):
-        self.drive = GoogleDrive(self.ga)
+        ga = GoogleAuth('pydrive2/test/settings/default.yaml')
+        ga.ServiceAuth()
+        self.drive = GoogleDrive(ga)
         self.file1 = self.drive.CreateFile()
-        self.file1.Upload()
+        pydrive_retry(self.file1.Upload)
 
     def tearDown(self):
-        self.file1.Delete()
+        pydrive_retry(self.file1.Delete)
 
 if __name__ == '__main__':
     unittest.main()
diff --git a/pydrive2/test/test_drive.py b/pydrive2/test/test_drive.py
index 918ec41c..adc45abc 100644
--- a/pydrive2/test/test_drive.py
+++ b/pydrive2/test/test_drive.py
@@ -1,21 +1,28 @@
 # -*- coding: utf-8 -*-
 import unittest
+import pytest
 
 from pydrive2.auth import GoogleAuth
 from pydrive2.drive import GoogleDrive
+from pydrive2.test.test_util import pydrive_retry, setup_credentials
 
 
 class GoogleDriveTest(unittest.TestCase):
     """Tests basic operations on meta-data information of the linked Google Drive account.
     """
 
-    ga = GoogleAuth('settings/test1.yaml')
-    ga.LocalWebserverAuth()
+    @classmethod
+    def setup_class(cls):
+        setup_credentials()
+
+        cls.ga = GoogleAuth('pydrive2/test/settings/default.yaml')
+        cls.ga.ServiceAuth()
+
 
     def test_01_About_Request(self):
         drive = GoogleDrive(self.ga)
 
-        about_object = drive.GetAbout()
+        about_object = pydrive_retry(drive.GetAbout)
         self.assertTrue(about_object is not None, "About object not loading.")
 
 
diff --git a/pydrive2/test/test_file.py b/pydrive2/test/test_file.py
index 8ca379e5..8a3e722f 100644
--- a/pydrive2/test/test_file.py
+++ b/pydrive2/test/test_file.py
@@ -2,6 +2,8 @@
 import filecmp
 import os
 import unittest
+import pytest
+import sys
 from io import BytesIO
 
 from six.moves import range
@@ -11,8 +13,8 @@
 from pydrive2.auth import GoogleAuth
 from pydrive2.drive import GoogleDrive
 from pydrive2.files import ApiRequestError, GoogleDriveFile
-
-from . import test_util
+from pydrive2.test import test_util
+from pydrive2.test.test_util import pydrive_retry, setup_credentials, create_file, delete_file
 
 
 class GoogleDriveFileTest(unittest.TestCase):
@@ -21,17 +23,33 @@ class GoogleDriveFileTest(unittest.TestCase):
   Equivalent to Files.insert, Files.update, Files.patch in Google Drive API.
   """
 
-  ga = GoogleAuth('settings/test1.yaml')
-  ga.LocalWebserverAuth()
-  first_file = 'a.png'
-  second_file = 'b.png'
+  first_file = 'first_file'
+  second_file = 'second_file'
+
+
+  @classmethod
+  def setup_class(cls):
+    setup_credentials()
+
+    create_file(cls.first_file, cls.first_file)
+    create_file(cls.second_file, cls.second_file)
+
+    cls.ga = GoogleAuth('pydrive2/test/settings/default.yaml')
+    cls.ga.ServiceAuth()
+
+
+  @classmethod
+  def tearDownClass(cls):
+    delete_file(cls.first_file)
+    delete_file(cls.second_file)
+
 
   def test_01_Files_Insert(self):
     drive = GoogleDrive(self.ga)
     file1 = drive.CreateFile()
     filename = 'firsttestfile'
     file1['title'] = filename
-    file1.Upload()  # Files.insert
+    pydrive_retry(file1.Upload) # Files.insert
 
     self.assertEqual(file1.metadata['title'], filename)
     file2 = drive.CreateFile({'id': file1['id']})  # Download file from id.
@@ -39,12 +57,13 @@ def test_01_Files_Insert(self):
 
     self.DeleteUploadedFiles(drive, [file1['id']])
 
+
   def test_02_Files_Insert_Unicode(self):
     drive = GoogleDrive(self.ga)
     file1 = drive.CreateFile()
     filename = u'첫번째 파일'
     file1['title'] = filename
-    file1.Upload()  # Files.insert
+    pydrive_retry(file1.Upload)  # Files.insert
 
     self.assertEqual(file1.metadata['title'], filename)
     file2 = drive.CreateFile({'id': file1['id']})  # Download file from id.
@@ -52,6 +71,7 @@ def test_02_Files_Insert_Unicode(self):
 
     self.DeleteUploadedFiles(drive, [file1['id']])
 
+
   def test_03_Files_Insert_Content_String(self):
     drive = GoogleDrive(self.ga)
     file1 = drive.CreateFile()
@@ -59,20 +79,22 @@ def test_03_Files_Insert_Content_String(self):
     content = 'hello world!'
     file1['title'] = filename
     file1.SetContentString(content)
-    file1.Upload()  # Files.insert
+    pydrive_retry(file1.Upload)  # Files.insert
 
     self.assertEqual(file1.GetContentString(), content)
 
-    file1.FetchContent()  # Force download and double check content
+    pydrive_retry(file1.FetchContent)  # Force download and double check content
     self.assertEqual(file1.metadata['title'], filename)
     self.assertEqual(file1.GetContentString(), content)
 
     file2 = drive.CreateFile({'id': file1['id']})  # Download file from id.
+    pydrive_retry(file2.FetchContent)
     self.assertEqual(file2.GetContentString(), content)
     self.assertEqual(file2.metadata['title'], filename)
 
     self.DeleteUploadedFiles(drive, [file1['id']])
 
+
   def test_04_Files_Insert_Content_Unicode_String(self):
     drive = GoogleDrive(self.ga)
     file1 = drive.CreateFile()
@@ -80,39 +102,44 @@ def test_04_Files_Insert_Content_Unicode_String(self):
     content = u'안녕 세상아!'
     file1['title'] = filename
     file1.SetContentString(content)
-    file1.Upload()  # Files.insert
+    pydrive_retry(file1.Upload)  # Files.insert
 
     self.assertEqual(file1.GetContentString(), content)
     self.assertEqual(file1.metadata['title'], filename)
-    file1.FetchContent()  # Force download and double check content.
+    pydrive_retry(file1.FetchContent)  # Force download and double check content.
     self.assertEqual(file1.GetContentString(), content)
 
     file2 = drive.CreateFile({'id': file1['id']})  # Download file from id.
+    pydrive_retry(file2.FetchContent)
     self.assertEqual(file2.GetContentString(), content)
     self.assertEqual(file2.metadata['title'], filename)
 
     self.DeleteUploadedFiles(drive, [file1['id']])
 
+
   def test_05_Files_Insert_Content_File(self):
-    self.DeleteOldFile(self.first_file+'1')
-    self.DeleteOldFile(self.first_file+'2')
+    delete_file(self.first_file+'1')
+    delete_file(self.first_file+'2')
     drive = GoogleDrive(self.ga)
     file1 = drive.CreateFile()
     filename = 'filecontent'
     file1['title'] = filename
     file1.SetContentFile(self.first_file)
-    file1.Upload()  # Files.insert
+    pydrive_retry(file1.Upload)  # Files.insert
 
     self.assertEqual(file1.metadata['title'], filename)
-    file1.FetchContent()  # Force download and double check content.
+    pydrive_retry(file1.FetchContent)  # Force download and double check content.
     file1.GetContentFile(self.first_file+'1')
     self.assertEqual(filecmp.cmp(self.first_file, self.first_file+'1'), True)
 
     file2 = drive.CreateFile({'id': file1['id']})  # Download file from id.
-    file2.GetContentFile(self.first_file+'2')
+    pydrive_retry(lambda: file2.GetContentFile(self.first_file+'2'))
     self.assertEqual(filecmp.cmp(self.first_file, self.first_file+'2'), True)
 
     self.DeleteUploadedFiles(drive, [file1['id']])
+    delete_file(self.first_file + '1')
+    delete_file(self.first_file + '2')
+
 
   def test_06_Files_Patch(self):
     drive = GoogleDrive(self.ga)
@@ -120,19 +147,20 @@ def test_06_Files_Patch(self):
     filename = 'prepatchtestfile'
     newfilename = 'patchtestfile'
     file1['title'] = filename
-    file1.Upload()  # Files.insert
+    pydrive_retry(file1.Upload)  # Files.insert
 
     self.assertEqual(file1.metadata['title'], filename)
     file1['title'] = newfilename
-    file1.Upload()  # Files.patch
+    pydrive_retry(file1.Upload)  # Files.patch
 
     self.assertEqual(file1.metadata['title'], newfilename)
     file2 = drive.CreateFile({'id': file1['id']})  # Download file from id.
-    file2.FetchMetadata()
+    pydrive_retry(file2.FetchMetadata)
     self.assertEqual(file2.metadata['title'], newfilename)
 
     self.DeleteUploadedFiles(drive, [file1['id']])
 
+
   def test_07_Files_Patch_Skipping_Content(self):
     drive = GoogleDrive(self.ga)
     file1 = drive.CreateFile()
@@ -142,17 +170,18 @@ def test_07_Files_Patch_Skipping_Content(self):
 
     file1['title'] = filename
     file1.SetContentString(content)
-    file1.Upload()  # Files.insert
+    pydrive_retry(file1.Upload)  # Files.insert
     self.assertEqual(file1.metadata['title'], filename)
 
     file1['title'] = newfilename
-    file1.Upload()  # Files.patch
+    pydrive_retry(file1.Upload)  # Files.patch
     self.assertEqual(file1.metadata['title'], newfilename)
     self.assertEqual(file1.GetContentString(), content)
     self.assertEqual(file1.GetContentString(), content)
 
     self.DeleteUploadedFiles(drive, [file1['id']])
 
+
   def test_08_Files_Update_String(self):
     drive = GoogleDrive(self.ga)
     file1 = drive.CreateFile()
@@ -163,25 +192,26 @@ def test_08_Files_Update_String(self):
 
     file1['title'] = filename
     file1.SetContentString(content)
-    file1.Upload()  # Files.insert
+    pydrive_retry(file1.Upload)  # Files.insert
     self.assertEqual(file1.metadata['title'], filename)
     self.assertEqual(file1.GetContentString(), content)
 
-    file1.FetchContent()  # Force download and double check content.
+    pydrive_retry(file1.FetchContent)  # Force download and double check content.
     self.assertEqual(file1.GetContentString(), content)
 
     file1['title'] = newfilename
     file1.SetContentString(newcontent)
-    file1.Upload()  # Files.update
+    pydrive_retry(file1.Upload)  # Files.update
     self.assertEqual(file1.metadata['title'], newfilename)
     self.assertEqual(file1.GetContentString(), newcontent)
     self.assertEqual(file1.GetContentString(), newcontent)
 
     self.DeleteUploadedFiles(drive, [file1['id']])
 
+
   def test_09_Files_Update_File(self):
-    self.DeleteOldFile(self.first_file+'1')
-    self.DeleteOldFile(self.second_file+'1')
+    delete_file(self.first_file+'1')
+    delete_file(self.second_file+'1')
     drive = GoogleDrive(self.ga)
     file1 = drive.CreateFile()
     filename = 'preupdatetestfile'
@@ -189,121 +219,130 @@ def test_09_Files_Update_File(self):
 
     file1['title'] = filename
     file1.SetContentFile(self.first_file)
-    file1.Upload()  # Files.insert
+    pydrive_retry(file1.Upload)  # Files.insert
     self.assertEqual(file1.metadata['title'], filename)
 
-    file1.FetchContent()  # Force download and double check content.
+    pydrive_retry(file1.FetchContent)  # Force download and double check content.
     file1.GetContentFile(self.first_file+'1')
     self.assertEqual(filecmp.cmp(self.first_file, self.first_file+'1'), True)
 
     file1['title'] = newfilename
     file1.SetContentFile(self.second_file)
-    file1.Upload()  # Files.update
+    pydrive_retry(file1.Upload)  # Files.update
     self.assertEqual(file1.metadata['title'], newfilename)
     file1.GetContentFile(self.second_file+'1')
     self.assertEqual(filecmp.cmp(self.second_file, self.second_file+'1'), True)
 
     self.DeleteUploadedFiles(drive, [file1['id']])
 
+    delete_file(self.first_file + '1')
+    delete_file(self.second_file + '1')
+
   # Tests for Trash/UnTrash/Delete.
   # ===============================
 
+
   def test_Files_Trash_File(self):
     drive = GoogleDrive(self.ga)
     file1 = drive.CreateFile()
-    file1.Upload()
+    pydrive_retry(file1.Upload)
     self.assertFalse(file1.metadata[u'labels'][u'trashed'])
 
     # Download to verify non-trashed state on GDrive.
     file2 = drive.CreateFile({'id': file1['id']})
-    file2.FetchMetadata()
+    pydrive_retry(file2.FetchMetadata)
     self.assertFalse(file2.metadata[u'labels'][u'trashed'])
 
-    file1.Trash()
+    pydrive_retry(file1.Trash)
     self.assertTrue(file1.metadata[u'labels'][u'trashed'])
 
-    file2.FetchMetadata()
+    pydrive_retry(file2.FetchMetadata)
     self.assertTrue(file2.metadata[u'labels'][u'trashed'])
 
     self.DeleteUploadedFiles(drive, [file1['id']])
 
+
   def test_Files_Trash_File_Just_ID(self):
     drive = GoogleDrive(self.ga)
     file1 = drive.CreateFile()
-    file1.Upload()
+    pydrive_retry(file1.Upload)
     self.assertFalse(file1.metadata[u'labels'][u'trashed'])
 
     # Trash file by ID.
     file2 = drive.CreateFile({'id': file1['id']})
-    file2.Trash()
+    pydrive_retry(file2.Trash)
 
     # Verify trashed by downloading metadata.
-    file1.FetchMetadata()
+    pydrive_retry(file1.FetchMetadata)
     self.assertTrue(file1.metadata[u'labels'][u'trashed'])
 
     self.DeleteUploadedFiles(drive, [file1['id']])
 
+
   def test_Files_UnTrash_File(self):
     drive = GoogleDrive(self.ga)
     file1 = drive.CreateFile()
-    file1.Upload()
-    file1.Trash()
+    pydrive_retry(file1.Upload)
+    pydrive_retry(file1.Trash)
     self.assertTrue(file1.metadata[u'labels'][u'trashed'])
 
     # Verify that file is trashed by downloading metadata.
     file2 = drive.CreateFile({'id': file1['id']})
-    file2.FetchMetadata()
+    pydrive_retry(file2.FetchMetadata)
     self.assertTrue(file2.metadata[u'labels'][u'trashed'])
 
     # Un-trash the file, and assert local metadata is updated correctly.
-    file1.UnTrash()
+    pydrive_retry(file1.UnTrash)
     self.assertFalse(file1.metadata[u'labels'][u'trashed'])
 
     # Re-fetch the metadata, and assert file un-trashed on GDrive.
-    file2.FetchMetadata()
+    pydrive_retry(file2.FetchMetadata)
     self.assertFalse(file2.metadata[u'labels'][u'trashed'])
 
     self.DeleteUploadedFiles(drive, [file1['id']])
 
+
   def test_Files_UnTrash_File_Just_ID(self):
     drive = GoogleDrive(self.ga)
     file1 = drive.CreateFile()
-    file1.Upload()
-    file1.Trash()
+    pydrive_retry(file1.Upload)
+    pydrive_retry(file1.Trash)
     self.assertTrue(file1.metadata[u'labels'][u'trashed'])
 
     file2 = drive.CreateFile({'id': file1['id']})
-    file2.UnTrash()  # UnTrash without fetching metadata.
+    pydrive_retry(file2.UnTrash)  # UnTrash without fetching metadata.
 
-    file1.FetchMetadata()
+    pydrive_retry(file1.FetchMetadata)
     self.assertFalse(file1.metadata[u'labels'][u'trashed'])
 
     self.DeleteUploadedFiles(drive, [file1['id']])
 
+
   def test_Files_Delete_File(self):
     drive = GoogleDrive(self.ga)
     file1 = drive.CreateFile()
-    file1.Upload()
+    pydrive_retry(file1.Upload)
     file2 = drive.CreateFile({'id': file1['id']})
 
-    file1.Delete()
+    pydrive_retry(file1.Delete)
 
     try:
-      file2.FetchMetadata()
+      pydrive_retry(file2.FetchMetadata)
       self.fail("File not deleted correctly.")
     except ApiRequestError as e:
       pass
 
+
   def test_Files_Delete_File_Just_ID(self):
     drive = GoogleDrive(self.ga)
     file1 = drive.CreateFile()
-    file1.Upload()
+    pydrive_retry(file1.Upload)
     file2 = drive.CreateFile({'id': file1['id']})
 
-    file2.Delete()
+    pydrive_retry(file2.Delete)
 
     try:
-      file1.FetchMetadata()
+      pydrive_retry(file1.FetchMetadata)
       self.fail("File not deleted correctly.")
     except ApiRequestError as e:
       pass
@@ -311,94 +350,100 @@ def test_Files_Delete_File_Just_ID(self):
   # Tests for Permissions.
   # ======================
 
+
   def test_Files_FetchMetadata_Fields(self):
     drive = GoogleDrive(self.ga)
     file1 = drive.CreateFile()
-    file1.Upload()
+    pydrive_retry(file1.Upload)
 
     self.assertFalse('permissions' in file1)
 
-    file1.FetchMetadata('permissions')
+    pydrive_retry(lambda: file1.FetchMetadata('permissions'))
     self.assertTrue('permissions' in file1)
-    file1.Delete()
+    pydrive_retry(file1.Delete)
+
 
   def test_Files_Insert_Permission(self):
     drive = GoogleDrive(self.ga)
     file1 = drive.CreateFile()
-    file1.Upload()
+    pydrive_retry(file1.Upload)
 
     # Verify only one permission before inserting permission.
-    permissions = file1.GetPermissions()
+    permissions = pydrive_retry(file1.GetPermissions)
     self.assertEqual(len(permissions), 1)
     self.assertEqual(len(file1['permissions']), 1)
 
     # Insert the permission.
-    permission = file1.InsertPermission({'type': 'anyone',
+    permission = pydrive_retry(lambda: file1.InsertPermission({'type': 'anyone',
                             'value': 'anyone',
-                            'role': 'reader'})
+                            'role': 'reader'}))
     self.assertTrue(permission)
     self.assertEqual(len(file1["permissions"]), 2)
-    self.assertEqual(file1["permissions"][1]["type"], "anyone")
+    self.assertEqual(file1["permissions"][0]["type"], "anyone")
 
-    permissions = file1.GetPermissions()
+    permissions = pydrive_retry(file1.GetPermissions)
     self.assertEqual(len(file1["permissions"]), 2)
-    self.assertEqual(file1["permissions"][1]["type"], "anyone")
-    self.assertEqual(permissions[1]["type"], "anyone")
+    self.assertEqual(file1["permissions"][0]["type"], "anyone")
+    self.assertEqual(permissions[0]["type"], "anyone")
 
     # Verify remote changes made.
     file2 = drive.CreateFile({'id': file1['id']})
-    permissions = file2.GetPermissions()
+    permissions = pydrive_retry(file2.GetPermissions)
     self.assertEqual(len(permissions), 2)
-    self.assertEqual(permissions[1]["type"], "anyone")
+    self.assertEqual(permissions[0]["type"], "anyone")
+
+    pydrive_retry(file1.Delete)
 
-    file1.Delete()
 
   def test_Files_Get_Permissions(self):
     drive = GoogleDrive(self.ga)
     file1 = drive.CreateFile()
-    file1.Upload()
+    pydrive_retry(file1.Upload)
 
     self.assertFalse('permissions' in file1)
 
-    permissions = file1.GetPermissions()
+    permissions = pydrive_retry(file1.GetPermissions)
     self.assertTrue(permissions is not None)
     self.assertTrue('permissions' in file1)
 
-    file1.Delete()
+    pydrive_retry(file1.Delete)
+
 
   def test_Files_Delete_Permission(self):
     drive = GoogleDrive(self.ga)
     file1 = drive.CreateFile()
-    file1.Upload()
-    file1.InsertPermission({'type': 'anyone',
+    pydrive_retry(file1.Upload)
+    pydrive_retry(lambda: file1.InsertPermission({'type': 'anyone',
                             'value': 'anyone',
-                            'role': 'reader'})
-    permissions = file1.GetPermissions()
+                            'role': 'reader'}))
+    permissions = pydrive_retry(file1.GetPermissions)
     self.assertEqual(len(permissions), 2)
     self.assertEqual(len(file1['permissions']), 2)
 
-    file1.DeletePermission(permissions[1]['id'])
+    pydrive_retry(lambda: file1.DeletePermission(permissions[0]['id']))
     self.assertEqual(len(file1['permissions']), 1)
 
     # Verify remote changes made.
     file2 = drive.CreateFile({'id': file1['id']})
-    permissions = file2.GetPermissions()
+    permissions = pydrive_retry(file2.GetPermissions)
     self.assertEqual(len(permissions), 1)
 
-    file1.Delete()
+    pydrive_retry(file1.Delete)
+
 
   def test_Files_Delete_Permission_Invalid(self):
     drive = GoogleDrive(self.ga)
     file1 = drive.CreateFile()
-    file1.Upload()
+    pydrive_retry(file1.Upload)
 
     try:
-      file1.DeletePermission('invalid id')
+      pydrive_retry(lambda: file1.DeletePermission('invalid id'))
       self.fail("Deleting invalid permission not raising exception.")
     except ApiRequestError as e:
       pass
 
-    file1.Delete()
+    pydrive_retry(file1.Delete)
+
 
   def test_GFile_Conversion_Lossless_String(self):
     drive = GoogleDrive(self.ga)
@@ -407,7 +452,7 @@ def test_GFile_Conversion_Lossless_String(self):
     # Upload a string, and convert into Google Doc format.
     test_string = 'Generic, non-exhaustive ASCII test string.'
     file1.SetContentString(test_string)
-    file1.Upload({'convert': True})
+    pydrive_retry(lambda: file1.Upload({'convert': True}))
 
     # Download string as plain text.
     downloaded_string = file1.GetContentString(mimetype='text/plain')
@@ -416,16 +461,17 @@ def test_GFile_Conversion_Lossless_String(self):
     # Download content into file and ensure that file content matches original
     # content string.
     downloaded_file_name = '_tmp_downloaded_file_name.txt'
-    file1.GetContentFile(downloaded_file_name, mimetype='text/plain')
+    pydrive_retry(lambda: file1.GetContentFile(downloaded_file_name, mimetype='text/plain'))
     downloaded_string = open(downloaded_file_name).read()
     self.assertEqual(test_string, downloaded_string, "Strings do not match")
 
     # Delete temp file.
-    os.remove(downloaded_file_name)
+    delete_file(downloaded_file_name)
 
   # Tests for GDrive conversion.
   # ============================
 
+
   def setup_gfile_conversion_test(self):
     drive = GoogleDrive(self.ga)
     file1 = drive.CreateFile()
@@ -441,12 +487,14 @@ def setup_gfile_conversion_test(self):
 
     return file1, file_name, original_file_content, downloaded_file_name
 
+
   def cleanup_gfile_conversion_test(self, file1, file_name,
                                     downloaded_file_name):
     # Delete temporary files.
     os.path.exists(file_name) and os.remove(file_name)
     os.path.exists(downloaded_file_name) and os.remove(downloaded_file_name)
-    file1.Delete()  # Delete uploaded file.
+    pydrive_retry(file1.Delete)  # Delete uploaded file.
+
 
   def test_GFile_Conversion_Remove_BOM(self):
     (file1, file_name, original_file_content, downloaded_file_name) = \
@@ -454,7 +502,7 @@ def test_GFile_Conversion_Remove_BOM(self):
     try:
       # Upload source_file and convert into Google Doc format.
       file1.SetContentFile(file_name)
-      file1.Upload({'convert': True})
+      pydrive_retry(lambda: file1.Upload({'convert': True}))
 
       # Download as string.
       downloaded_content_no_bom = file1.GetContentString(mimetype='text/plain',
@@ -464,7 +512,7 @@ def test_GFile_Conversion_Remove_BOM(self):
       self.assertEqual(original_file_content, downloaded_content_no_bom)
 
       # Download as file.
-      file1.GetContentFile(downloaded_file_name, remove_bom=True)
+      pydrive_retry(lambda: file1.GetContentFile(downloaded_file_name, remove_bom=True))
       downloaded_content = open(downloaded_file_name).read()
       downloaded_content = test_util.StripNewlines(downloaded_content)
       self.assertEqual(original_file_content, downloaded_content)
@@ -472,6 +520,7 @@ def test_GFile_Conversion_Remove_BOM(self):
     finally:
       self.cleanup_gfile_conversion_test(file1, file_name, downloaded_file_name)
 
+
   def test_Gfile_Conversion_Add_Remove_BOM(self):
     """Tests whether you can switch between the BOM appended and removed
     version on the fly."""
@@ -479,7 +528,7 @@ def test_Gfile_Conversion_Add_Remove_BOM(self):
         self.setup_gfile_conversion_test()
     try:
       file1.SetContentFile(file_name)
-      file1.Upload({'convert': True})
+      pydrive_retry(lambda: file1.Upload({'convert': True}))
 
       content_bom = file1.GetContentString(mimetype='text/plain')
       content_no_bom = file1.GetContentString(mimetype='text/plain',
@@ -493,9 +542,10 @@ def test_Gfile_Conversion_Add_Remove_BOM(self):
     finally:
       self.cleanup_gfile_conversion_test(file1, file_name, downloaded_file_name)
 
+
   def test_InsertPrefix(self):
     # Create BytesIO.
-    file_obj = BytesIO('abc')
+    file_obj = BytesIO('abc'.encode('utf8'))
     original_length = len(file_obj.getvalue())
     char_to_insert = u'\ufeff'.encode('utf8')
 
@@ -505,10 +555,11 @@ def test_InsertPrefix(self):
     self.assertGreater(modified_length, original_length)
     self.assertEqual(file_obj.getvalue(), u'\ufeffabc'.encode('utf8'))
 
+
   def test_InsertPrefixLarge(self):
     # Create BytesIO.
     test_content = 'abc' * 800
-    file_obj = BytesIO(test_content)
+    file_obj = BytesIO(test_content.encode('utf-8'))
     original_length = len(file_obj.getvalue())
     char_to_insert = u'\ufeff'.encode('utf8')
 
@@ -519,6 +570,7 @@ def test_InsertPrefixLarge(self):
     expected_content = u'\ufeff' + test_content
     self.assertEqual(file_obj.getvalue(), expected_content.encode('utf8'))
 
+
   def test_RemovePrefix(self):
     # Create BytesIO.
     file_obj = BytesIO(u'\ufeffabc'.encode('utf8'))
@@ -529,7 +581,8 @@ def test_RemovePrefix(self):
     GoogleDriveFile._RemovePrefix(file_obj, char_to_remove)
     modified_length = len(file_obj.getvalue())
     self.assertLess(modified_length, original_length)
-    self.assertEqual(file_obj.getvalue(), 'abc')
+    self.assertEqual(file_obj.getvalue(), 'abc'.encode('utf8'))
+
 
   def test_RemovePrefixLarge(self):
     # Create BytesIO.
@@ -542,7 +595,7 @@ def test_RemovePrefixLarge(self):
     GoogleDriveFile._RemovePrefix(file_obj, char_to_remove)
     modified_length = len(file_obj.getvalue())
     self.assertLess(modified_length, original_length)
-    self.assertEqual(file_obj.getvalue(), test_content[1:])
+    self.assertEqual(file_obj.getvalue(), test_content[1:].encode('utf8'))
 
   # Setup for concurrent upload testing.
   # =====================================
@@ -553,8 +606,11 @@ def __init__(self, gdrive_file, generate_http=False):
       if generate_http:
         self.param = {"http": gdrive_file.auth.Get_Http_Object()}
 
+
     def run(self):
-      self.gdrive_file.Upload(param=self.param)
+      pydrive_retry(lambda: self.gdrive_file.Upload(param=self.param))
+
+  FILE_UPLOAD_COUNT = 10
 
   def _parallel_uploader(self, num_of_uploads, num_of_workers,
                          use_per_thread_http=False):
@@ -572,8 +628,10 @@ def _parallel_uploader(self, num_of_uploads, num_of_workers,
       upload_files.append(up_file)
 
     # Ensure there are no files with the random file name.
-    files = drive.ListFile(param={'q': "title = '%s' and trashed = false" %
+    files = pydrive_retry(
+        lambda: drive.ListFile(param={'q': "title = '%s' and trashed = false" %
                                remote_name}).GetList()
+    )
     self.assertTrue(len(files) == 0)
 
     # Submit upload jobs to ThreadPoolExecutor.
@@ -588,35 +646,34 @@ def _parallel_uploader(self, num_of_uploads, num_of_workers,
       self.assertIsNone(future.exception())
     thread_pool.shutdown()
 
-    # Ensure 10 files were uploaded.
-    files = drive.ListFile(param={'q': "title = '%s' and trashed = false" %
+    # Ensure all files were uploaded.
+    files = pydrive_retry(
+        lambda: drive.ListFile(param={'q': "title = '%s' and trashed = false" %
                                        remote_name}).GetList()
-    self.assertTrue(len(files) == 10)
+    )
+    self.assertTrue(len(files) == self.FILE_UPLOAD_COUNT)
 
     # Remove uploaded files.
     self.DeleteUploadedFiles(drive, [fi['id'] for fi in upload_files])
 
-  @timeout_decorator.timeout(80)
+  @pytest.mark.skipif(sys.platform == 'win32', reason="timeout_decorator doesn't support Windows")
+  @timeout_decorator.timeout(160)
   def test_Parallel_Files_Insert_File_Auto_Generated_HTTP(self):
-    self._parallel_uploader(10, 10)
+    self._parallel_uploader(self.FILE_UPLOAD_COUNT, 10)
 
-  @timeout_decorator.timeout(80)
+  @pytest.mark.skipif(sys.platform == 'win32', reason="timeout_decorator doesn't support Windows")
+  @timeout_decorator.timeout(160)
   def test_Parallel_Insert_File_Passed_HTTP(self):
-    self._parallel_uploader(10, 10, True)
+    self._parallel_uploader(self.FILE_UPLOAD_COUNT, 10, True)
 
   # Helper functions.
   # =================
 
-  def DeleteOldFile(self, file_name):
-    try:
-      os.remove(file_name)
-    except OSError:
-      pass
 
   def DeleteUploadedFiles(self, drive, ids):
     for element in ids:
       tmp_file = drive.CreateFile({'id': element})
-      tmp_file.Delete()
+      pydrive_retry(tmp_file.Delete)
 
 
 if __name__ == '__main__':
diff --git a/pydrive2/test/test_filelist.py b/pydrive2/test/test_filelist.py
index 6d836059..4426163a 100644
--- a/pydrive2/test/test_filelist.py
+++ b/pydrive2/test/test_filelist.py
@@ -2,40 +2,45 @@
 import os
 import sys
 import unittest
+import pytest
 
 from pydrive2.auth import GoogleAuth
 from pydrive2.drive import GoogleDrive
 from pydrive2.test import test_util
+from pydrive2.test.test_util import pydrive_retry, pydrive_list_item, setup_credentials
 
 
 class GoogleDriveFileListTest(unittest.TestCase):
   """Tests operations of files.GoogleDriveFileList class.
   Equivalent to Files.list in Google Drive API.
   """
-  ga = GoogleAuth('settings/test1.yaml')
-  ga.LocalWebserverAuth()
-  drive = GoogleDrive(ga)
+
+  @classmethod
+  def setup_class(cls):
+    setup_credentials()
+
+    cls.ga = GoogleAuth('pydrive2/test/settings/default.yaml')
+    cls.ga.ServiceAuth()
+    cls.drive = GoogleDrive(cls.ga)
+
 
   def test_01_Files_List_GetList(self):
     drive = GoogleDrive(self.ga)
-    flist = drive.ListFile({'q': "title = '%s' and trashed = false"
-                                 % self.title})
-    files = flist.GetList()  # Auto iterate every file
-    for file1 in self.file_list:
+    query = "title = '{}' and trashed = false".format(self.title)
+    for file1 in pydrive_list_item(drive, query):
       found = False
-      for file2 in files:
+      for file2 in pydrive_list_item(drive, query):
         if file1['id'] == file2['id']:
           found = True
       self.assertEqual(found, True)
 
+
   def test_02_Files_List_ForLoop(self):
     drive = GoogleDrive(self.ga)
-    flist = drive.ListFile({'q': "title = '%s' and trashed = false"%self.title,
-                            'maxResults': 2})
+    query = "title = '{}' and trashed = false".format(self.title)
     files = []
-    for x in flist:  # Build iterator to access files simply with for loop
-      self.assertTrue(len(x) <= 2)
-      files.extend(x)
+    for x in pydrive_list_item(drive, query, 2):  # Build iterator to access files simply with for loop
+      files.append(x)
     for file1 in self.file_list:
       found = False
       for file2 in files:
@@ -43,6 +48,7 @@ def test_02_Files_List_ForLoop(self):
           found = True
       self.assertEqual(found, True)
 
+
   def test_03_Files_List_GetList_Iterate(self):
     drive = GoogleDrive(self.ga)
     flist = drive.ListFile({'q': "title = '%s' and trashed = false"%self.title,
@@ -50,7 +56,7 @@ def test_03_Files_List_GetList_Iterate(self):
     files = []
     while True:
       try:
-        x = flist.GetList()
+        x = pydrive_retry(flist.GetList)
         self.assertTrue(len(x) <= 2)
         files.extend(x)
       except StopIteration:
@@ -62,21 +68,19 @@ def test_03_Files_List_GetList_Iterate(self):
           found = True
       self.assertEqual(found, True)
 
+
   def test_File_List_Folders(self):
     drive = GoogleDrive(self.ga)
     folder1 = drive.CreateFile(
       {'mimeType': 'application/vnd.google-apps.folder',
        'title': self.title})
-    folder1.Upload()
+    pydrive_retry(folder1.Upload)
     self.file_list.append(folder1)
-
-    flist = drive.ListFile({'q': "title = '%s' and trashed = false"
-                                 % self.title})
+    query = "title = '{}' and trashed = false".format(self.title)
     count = 0
-    for _flist in flist:
-      for file1 in _flist:
-        self.assertFileInFileList(file1)
-        count += 1
+    for file1 in pydrive_list_item(drive, query):
+      self.assertFileInFileList(file1)
+      count += 1
 
     self.assertTrue(count == 11)
 
@@ -88,7 +92,7 @@ def setUp(self):
     for x in range(0, 10):
       file1 = self.drive.CreateFile()
       file1['title'] = title
-      file1.Upload()
+      pydrive_retry(file1.Upload)
       file_list.append(file1)
 
     self.title = title
@@ -97,7 +101,7 @@ def setUp(self):
   def tearDown(self):
     # Deleting uploaded files.
     for file1 in self.file_list:
-      file1.Delete()
+      pydrive_retry(file1.Delete)
 
   def assertFileInFileList(self, file_object):
     found = False
diff --git a/pydrive2/test/test_oauth.py b/pydrive2/test/test_oauth.py
index fb9fed6e..d6b8ae9d 100644
--- a/pydrive2/test/test_oauth.py
+++ b/pydrive2/test/test_oauth.py
@@ -1,71 +1,80 @@
 import unittest
 import os
 import time
+import pytest
 
 from pydrive2.auth import GoogleAuth
+from pydrive2.test.test_util import setup_credentials, delete_file
+
 
 class GoogleAuthTest(unittest.TestCase):
   """Tests basic OAuth2 operations of auth.GoogleAuth."""
 
+  @pytest.mark.manual
   def test_01_LocalWebserverAuthWithClientConfigFromFile(self):
     # Delete old credentials file
-    self.DeleteOldCredentialsFile('credentials/1.dat')
+    delete_file('credentials/1.dat')
     # Test if authentication works with config read from file
-    ga = GoogleAuth('settings/test1.yaml')
+    ga = GoogleAuth('pydrive2/test/settings/test_oauth_test_01.yaml')
     ga.LocalWebserverAuth()
     self.assertEqual(ga.access_token_expired, False)
     # Test if correct credentials file is created
     self.CheckCredentialsFile('credentials/1.dat')
     time.sleep(1)
 
+  @pytest.mark.manual
   def test_02_LocalWebserverAuthWithClientConfigFromSettings(self):
     # Delete old credentials file
-    self.DeleteOldCredentialsFile('credentials/2.dat')
+    delete_file('credentials/2.dat')
     # Test if authentication works with config read from settings
-    ga = GoogleAuth('settings/test2.yaml')
+    ga = GoogleAuth('pydrive2/test/settings/test_oauth_test_02.yaml')
     ga.LocalWebserverAuth()
     self.assertEqual(ga.access_token_expired, False)
     # Test if correct credentials file is created
     self.CheckCredentialsFile('credentials/2.dat')
     time.sleep(1)
 
+  @pytest.mark.manual
   def test_03_LocalWebServerAuthWithNoCredentialsSaving(self):
     # Delete old credentials file
-    self.DeleteOldCredentialsFile('credentials/4.dat')
+    delete_file('credentials/4.dat')
     # Provide wrong credentials file
-    ga = GoogleAuth('settings/test3.yaml')
+    ga = GoogleAuth('pydrive2/test/settings/test_oauth_test_03.yaml')
     ga.LocalWebserverAuth()
     self.assertEqual(ga.access_token_expired, False)
     # Test if correct credentials file is created
     self.CheckCredentialsFile('credentials/4.dat', no_file=True)
     time.sleep(1)
 
+  @pytest.mark.manual
   def test_04_CommandLineAuthWithClientConfigFromFile(self):
     # Delete old credentials file
-    self.DeleteOldCredentialsFile('credentials/1.dat')
+    delete_file('credentials/1.dat')
     # Test if authentication works with config read from file
-    ga = GoogleAuth('settings/test4.yaml')
+    ga = GoogleAuth('pydrive2/test/settings/test_oauth_test_04.yaml')
     ga.CommandLineAuth()
     self.assertEqual(ga.access_token_expired, False)
     # Test if correct credentials file is created
     self.CheckCredentialsFile('credentials/1.dat')
     time.sleep(1)
 
+  @pytest.mark.manual
   def test_05_ConfigFromSettingsWithoutOauthScope(self):
     # Test if authentication works without oauth_scope
-    ga = GoogleAuth('settings/test5.yaml')
+    ga = GoogleAuth('pydrive2/test/settings/test_oauth_test_05.yaml')
     ga.LocalWebserverAuth()
     self.assertEqual(ga.access_token_expired, False)
     time.sleep(1)
 
-  def DeleteOldCredentialsFile(self, credentials):
-    try:
-      os.remove(credentials)
-    except OSError:
-      pass
+  def test_06_ServiceAuthFromSavedCredentialsFile(self):
+    setup_credentials("credentials/6.dat")
+    ga = GoogleAuth('pydrive2/test/settings/test_oauth_test_06.yaml')
+    ga.ServiceAuth()
+    self.assertEqual(ga.access_token_expired, False)
+    time.sleep(1)
 
   def CheckCredentialsFile(self, credentials, no_file=False):
-    ga = GoogleAuth('settings/default.yaml')
+    ga = GoogleAuth('pydrive2/test/settings/test_oauth_default.yaml')
     ga.LoadCredentialsFile(credentials)
     self.assertEqual(ga.access_token_expired, no_file)
 
diff --git a/pydrive2/test/test_util.py b/pydrive2/test/test_util.py
index 294d9188..abf0db0f 100644
--- a/pydrive2/test/test_util.py
+++ b/pydrive2/test/test_util.py
@@ -1,8 +1,61 @@
+import unittest
 import random
 import re
+import os
+
+from funcy import retry
+from funcy.py3 import cat
+from pydrive2.files import ApiRequestError
 
 newline_pattern = re.compile(r'[\r\n]')
 
+GDRIVE_USER_CREDENTIALS_DATA = "GDRIVE_USER_CREDENTIALS_DATA"
+DEFAULT_USER_CREDENTIALS_FILE = "credentials/default.dat"
+
+
+def setup_credentials(credentials_path=DEFAULT_USER_CREDENTIALS_FILE):
+    if os.getenv(GDRIVE_USER_CREDENTIALS_DATA):
+        if not os.path.exists(os.path.dirname(credentials_path)):
+            os.makedirs(os.path.dirname(credentials_path), exist_ok=True)
+        with open(
+                credentials_path, "w"
+        ) as credentials_file:
+            credentials_file.write(
+                os.getenv(GDRIVE_USER_CREDENTIALS_DATA)
+            )
+
+
+class PyDriveRetriableError(Exception):
+    pass
+
+
+# 15 tries, start at 0.5s, multiply by golden ratio, cap at 20s
+@retry(15, PyDriveRetriableError, timeout=lambda a: min(0.5 * 1.618 ** a, 20))
+def pydrive_retry(call):
+    try:
+        result = call()
+    except ApiRequestError as exception:
+        retry_codes = ["403", "500", "502", "503", "504"]
+        if any(
+            "HttpError {}".format(code) in str(exception)
+            for code in retry_codes
+        ):
+            raise PyDriveRetriableError("Google API request failed")
+        raise
+    return result
+
+
+def pydrive_list_item(drive, query, max_results=1000):
+    param = {"q": query, "maxResults": max_results}
+
+    file_list = drive.ListFile(param)
+
+    # Isolate and decorate fetching of remote drive items in pages
+    get_list = lambda: pydrive_retry(lambda: next(file_list, None))
+
+    # Fetch pages until None is received, lazily flatten the thing
+    return cat(iter(get_list, None))
+
 
 def CreateRandomFileName():
     hash = random.getrandbits(128)
@@ -10,4 +63,14 @@ def CreateRandomFileName():
 
 
 def StripNewlines(string):
-    return newline_pattern.sub("", string)
\ No newline at end of file
+    return newline_pattern.sub("", string)
+
+
+def create_file(path, content):
+    with open(path, "w") as f:
+        f.write(content)
+
+
+def delete_file(path):
+    if os.path.exists(path):
+        os.remove(path)
diff --git a/pytest.ini b/pytest.ini
new file mode 100644
index 00000000..197f7632
--- /dev/null
+++ b/pytest.ini
@@ -0,0 +1,3 @@
+[pytest]
+markers =
+    manual: mark tests to be runnable only in local environment and require user manual actions.
diff --git a/scripts/ci/script.sh b/scripts/ci/script.sh
index 5dfafbc6..025be26d 100644
--- a/scripts/ci/script.sh
+++ b/scripts/ci/script.sh
@@ -3,4 +3,4 @@
 set -x
 set -e
 
-py.test -v -s
+py.test -v -s -m "not manual"
diff --git a/setup.py b/setup.py
index 394ad110..d500ffc7 100644
--- a/setup.py
+++ b/setup.py
@@ -20,6 +20,6 @@
         "pyOpenSSL >= 19.1.0"
     ],
     extras_require={
-        "tests": ["timeout-decorator"],
+        "tests": ["pytest>=4.6.0", "timeout-decorator", "funcy>=1.14"],
     },
 )