added support for --testcase flag in ansible-test (ansible#36134)

* added support for --testcase flag in ansible-test

* fixed command format

* added tab completion

* fixed sanity issues

* added documenation for --testcase

* don't autocomplete when multiple modules are selected

docs/docsite/rst/dev_guide/testing_integration.rst

@@ -219,6 +219,11 @@ To run integration tests for a specific module::
 
     ansible-test network-integration --inventory  /path/to/ansible/test/integration/inventory.networking vyos_vlan
 
+To run a single test case on a specific module::
+
+    # Only run vyos_vlan/tests/cli/basic.yaml
+    ansible-test network-integration --inventory  /path/to/ansible/test/integration/inventory.networking vyos_vlan --testcase basic
+
 To run integration tests for a specific transport::
 
     # Only run nxapi test

test/runner/lib/config.py

@@ -193,6 +193,7 @@ def __init__(self, args):
 
         self.platform = args.platform  # type: list [str]
         self.inventory = args.inventory  # type: str
+        self.testcase = args.testcase  # type: str
 
 
 class UnitsConfig(TestConfig):

test/runner/lib/executor.py

@@ -943,6 +943,10 @@ def command_integration_role(args, target, start_at_task):
         if args.diff:
             cmd += ['--diff']
 
+        if isinstance(args, NetworkIntegrationConfig):
+            if args.testcase:
+                cmd += ['-e', 'testcase=%s' % args.testcase]
+
         if args.verbosity:
             cmd.append('-' + ('v' * args.verbosity))
 

test/runner/test.py

@@ -264,6 +264,10 @@ def parse_args():
                                      metavar='PATH',
                                      help='path to inventory used for tests')
 
+    network_integration.add_argument('--testcase',
+                                     metavar='TESTCASE',
+                                     help='limit a test to a specified testcase').completer = complete_network_testcase
+
     windows_integration = subparsers.add_parser('windows-integration',
                                                 parents=[integration],
                                                 help='windows integration tests')
@@ -648,6 +652,31 @@ def complete_network_platform(prefix, parsed_args, **_):
     return [i for i in images if i.startswith(prefix) and (not parsed_args.platform or i not in parsed_args.platform)]
 
 
+def complete_network_testcase(prefix, parsed_args, **_):
+    """
+    :type prefix: unicode
+    :type parsed_args: any
+    :rtype: list[str]
+    """
+    testcases = []
+
+    # since testcases are module specific, don't autocomplete if more than one
+    # module is specidied
+    if len(parsed_args.include) != 1:
+        return []
+
+    test_dir = 'test/integration/targets/%s/tests' % parsed_args.include[0]
+    connections = os.listdir(test_dir)
+
+    for conn in connections:
+        if os.path.isdir(os.path.join(test_dir, conn)):
+            for testcase in os.listdir(os.path.join(test_dir, conn)):
+                if testcase.startswith(prefix):
+                    testcases.append(testcase.split('.')[0])
+
+    return testcases
+
+
 def complete_sanity_test(prefix, parsed_args, **_):
     """
     :type prefix: unicode