added feature only fetch the tests

CHANGELOG.md

@@ -4,6 +4,7 @@
 ### Modified
 - Add fixture for git user configuration
 - Skip "Publish to Test PyPi" workflow when there is no change on setup.py
+- Added support to pick the only changed/modified and newly added tests
 
 ## [0.4.4] - 2020-03-21
 ### Fixed

README.rst

@@ -87,6 +87,7 @@ Usage
 
   $ pytest --picked --mode=unstaged  # default
 
+  $ pytest --picked --mode=onlychanged
 
 Features
 --------

pytest_picked/modes.py

@@ -9,7 +9,6 @@ def __init__(self, test_file_convention):
 
     def affected_tests(self):
         raw_output = self.git_output()
-
         re_list = [
             item.replace(".", r"\.").replace("*", ".*")
             for item in self.test_file_convention
@@ -26,6 +25,28 @@ def affected_tests(self):
                     files.append(file_or_folder)
         return files, folders
 
+    def only_tests(self):
+        raw_output = self.git_output()
+        re_list = [
+            item.replace(".", r"\.").replace("*", ".*")
+            for item in self.test_file_convention
+        ]
+        test_file_regex = r"(\/|^)" + r"|".join(re_list)
+        test_regex = r"(?<=def\s).*test.*(?=\()"
+
+        tests = []
+
+        last_file_name = None
+        for candidate in raw_output.splitlines():
+            file_or_test = self.parser(candidate)
+            if file_or_test:
+                if re.search(test_file_regex, file_or_test):
+                    last_file_name = file_or_test
+                elif re.search(test_regex, file_or_test):
+                    match = re.findall(test_regex, file_or_test)
+                    tests.append(last_file_name + "::" + match[0])
+        return tests, []
+
     def git_output(self):
         output = subprocess.run(self.command(), stdout=subprocess.PIPE)  # nosec
         return output.stdout.decode("utf-8").expandtabs()
@@ -127,3 +148,36 @@ def parser(self, candidate):
             indicator_index = candidate.find(rename_indicator)
             start_path_index = indicator_index + len(rename_indicator)
         return candidate[start_path_index:]
+
+
+class OnlyChanged(Mode):
+    def command(self):
+        return ["git", "diff"]
+
+    def parser(self, candidate):
+        """
+        Discard the first 6 characters in case of file name.
+
+        Parse the modified file using the file indicator '+++ b/'
+        Parse affected tests from using regex 'def' and '@@'
+        The command output would look like this:
+        diff --git a/tests/migrations/auto.py b/tests/migrations/auto.py
+        index 2ce07c4..ebd406e 100644
+        --- a/tests/migrations/auto.py
+        +++ b/tests/migrations/auto.py
+        @@ -181,6 +181,7 @@ def test_positive_migration(session, ad_data):
+
+        Reference:
+        https://git-scm.com/docs/git-diff#git-diff
+        """
+        start_path_index = 6
+        file_indicator = "+++ b/"
+        modified_test_indicator = "@@ "
+        new_test_indicator = "+def"
+
+        if candidate.startswith(file_indicator):
+            return candidate[start_path_index:]
+        if candidate.startswith(modified_test_indicator):
+            return candidate
+        if candidate.startswith(new_test_indicator):
+            return candidate

pytest_picked/plugin.py

@@ -2,7 +2,7 @@
 
 import _pytest
 
-from .modes import Branch, Unstaged
+from .modes import Branch, OnlyChanged, Unstaged
 
 
 def pytest_addoption(parser):
@@ -25,7 +25,7 @@ def pytest_addoption(parser):
         dest="picked_mode",
         default="unstaged",
         required=False,
-        help="Options: unstaged, branch",
+        help="Options: unstaged, branch, onlychanged",
     )
 
 
@@ -36,6 +36,7 @@ def _get_affected_paths(config):
     modes = {
         "branch": Branch(test_file_convention),
         "unstaged": Unstaged(test_file_convention),
+        "onlychanged": OnlyChanged(test_file_convention),
     }
     try:
         mode = modes[picked_mode]
@@ -45,7 +46,10 @@ def _get_affected_paths(config):
         config.args = []
         raise ValueError(error)
     else:
-        return mode.affected_tests()
+        if picked_mode == "onlychanged":
+            return mode.only_tests()
+        else:
+            return mode.affected_tests()
 
 
 def pytest_configure(config):
@@ -62,7 +66,6 @@ def pytest_collection_modifyitems(session, config, items):
     picked_type = config.getoption("picked")
     if not picked_type or picked_type != "first":
         return
-
     affected_files, affected_folders = _get_affected_paths(config)
     match_paths = affected_files + affected_folders
     # only reorder if there was anything matched