Add test verification to ansible-test. (#22636)

* Add unified git diff parser.
* Add metadata and diff handling.
* Add test confidence/verification to bot output.

test/runner/lib/metadata.py

@@ -0,0 +1,82 @@
+"""Test metadata for passing data to delegated tests."""
+from __future__ import absolute_import, print_function
+
+import json
+
+from lib.util import (
+    display,
+)
+
+from lib.diff import (
+    parse_diff,
+    FileDiff,
+)
+
+
+class Metadata(object):
+    """Metadata object for passing data to delegated tests."""
+    def __init__(self):
+        """Initialize metadata."""
+        self.changes = {}  # type: dict [str, tuple[tuple[int, int]]
+
+    def populate_changes(self, diff):
+        """
+        :type diff: list[str] | None
+        """
+        patches = parse_diff(diff)
+        patches = sorted(patches, key=lambda k: k.new.path)  # type: list [FileDiff]
+
+        self.changes = dict((patch.new.path, tuple(patch.new.ranges)) for patch in patches)
+
+        renames = [patch.old.path for patch in patches if patch.old.path != patch.new.path and patch.old.exists and patch.new.exists]
+        deletes = [patch.old.path for patch in patches if not patch.new.exists]
+
+        # make sure old paths which were renamed or deleted are registered in changes
+        for path in renames + deletes:
+            if path in self.changes:
+                # old path was replaced with another file
+                continue
+
+            # failed tests involving deleted files should be using line 0 since there is no content remaining
+            self.changes[path] = ((0, 0),)
+
+    def to_dict(self):
+        """
+        :rtype: dict[str, any]
+        """
+        return dict(
+            changes=self.changes,
+        )
+
+    def to_file(self, path):
+        """
+        :type path: path
+        """
+        data = self.to_dict()
+
+        display.info('>>> Metadata: %s\n%s' % (path, data), verbosity=3)
+
+        with open(path, 'w') as data_fd:
+            json.dump(data, data_fd, sort_keys=True, indent=4)
+
+    @staticmethod
+    def from_file(path):
+        """
+        :type path: str
+        :rtype: Metadata
+        """
+        with open(path, 'r') as data_fd:
+            data = json.load(data_fd)
+
+        return Metadata.from_dict(data)
+
+    @staticmethod
+    def from_dict(data):
+        """
+        :type data: dict[str, any]
+        :rtype: Metadata
+        """
+        metadata = Metadata()
+        metadata.changes = data['changes']
+
+        return metadata