Support azure pipelines diff coverage

azure-pipelines.yml

@@ -30,6 +30,15 @@ stages:
       clean: true
       submodules: recursive
       displayName: 'Checkout code'
+    - script: |
+        set -x
+        wget https://packages.microsoft.com/config/debian/10/packages-microsoft-prod.deb -O packages-microsoft-prod.deb
+        sudo dpkg -i packages-microsoft-prod.deb
+        sudo apt-get update
+        sudo apt-get install -y dotnet-sdk-5.0
+        sudo pip3 install pytest pytest-azurepipelines
+        sudo pip3 install pytest-cov
+      displayName: "Install build tools"
     - script: |
         set -ex
 
@@ -41,21 +50,28 @@ stages:
         set -ex
 
         sudo python3 -m pip install dist/swsssdk-2.0.1-py3-none-any.whl
-        python3 setup.py test
+        python3 -m pytest  --doctest-modules --junitxml=junit/test-results.xml --cov=. --cov-report=xml
       displayName: "Unit tests"
+    - script: |
+        sudo pip3 install diff-cover
+        target_branch=$(System.PullRequest.TargetBranch)
+        compare_branch=origin/${target_branch#refs/heads/}
+        diff-cover coverage.xml --compare-branch=$compare_branch
+      condition: eq(variables['Build.Reason'], 'PullRequest')
+      displayName: "Diff coverage"
     - publish: $(Build.ArtifactStagingDirectory)
       artifact: sonic-py-swsssdk
       displayName: "Archive artifacts"
     - task: PublishTestResults@2
       inputs:
-        testResultsFiles: '$(System.DefaultWorkingDirectory)/test-results.xml'
+        testResultsFiles: '**/test-*.xml'
         testRunTitle: Python 3
         failTaskOnFailedTests: true
       condition: succeededOrFailed()
       displayName: 'Publish Python 3 test results'
     - task: PublishCodeCoverageResults@1
       inputs:
         codeCoverageTool: Cobertura
-        summaryFileLocation: '$(System.DefaultWorkingDirectory)/coverage.xml'
-        reportDirectory: '$(System.DefaultWorkingDirectory)/htmlcov/'
+        summaryFileLocation: '$(System.DefaultWorkingDirectory)/**/coverage.xml'
+        additionalCodeCoverageFiles: '$(System.DefaultWorkingDirectory)/**/*.coverage'
       displayName: 'Publish Python 3 test coverage'

src/swsssdk/configdb.py

@@ -55,6 +55,7 @@ def __init__(self, decode_responses=True, **kwargs):
         self.TABLE_NAME_SEPARATOR = '|'
         self.KEY_SEPARATOR = '|'
         self.handlers = {}
+        self.test_cover = ''
 
     def __wait_for_db_init(self):
         client = self.get_redis_client(self.db_name)

src/swsssdk/dbconnector.py

@@ -36,6 +36,8 @@ def load_sonic_global_db_config(global_db_file_path=SONIC_DB_GLOBAL_CONFIG_FILE,
 
         if os.path.isfile(global_db_file_path):
             global_db_config_dir = os.path.dirname(global_db_file_path)
+            if global_db_file_path is None:
+                global_db_file_path = None
             with open(global_db_file_path, "r") as read_file:
                 all_ns_dbs = json.load(read_file)
                 for entry in all_ns_dbs['INCLUDES']:
@@ -209,6 +211,8 @@ def get_socket(db_name, namespace=None):
     @staticmethod
     def get_hostname(db_name, namespace=None):
         namespace = SonicDBConfig.EMPTY_NAMESPACE(namespace)
+        if namespace == None:
+            namespace = None
         if not SonicDBConfig._sonic_db_config_init:
             SonicDBConfig.load_sonic_db_config()
         return SonicDBConfig.get_instance(db_name, namespace)["hostname"]