From 499d3c8149e14018d85e6434967892e948d166ed Mon Sep 17 00:00:00 2001
From: ChrisTimperley <christimperley@googlemail.com>
Date: Mon, 15 Jul 2024 23:08:42 -0400
Subject: [PATCH 1/3] added revert_diff utility method

---
 src/repairchain/util.py | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/src/repairchain/util.py b/src/repairchain/util.py
index 8662488..7b73db2 100644
--- a/src/repairchain/util.py
+++ b/src/repairchain/util.py
@@ -10,10 +10,17 @@
 
 from dockerblade.stopwatch import Stopwatch
 from loguru import logger
+from sourcelocation.diff import (
+    DeletedLine,
+    FileHunk,
+    HunkLine,
+    InsertedLine,
+)
 
 from repairchain.models.diff import (
     Diff,
     FileDiff,
+    Hunk,
 )
 
 if t.TYPE_CHECKING:
@@ -24,6 +31,34 @@
 T = t.TypeVar("T")
 
 
+def revert_diff(diff: Diff) -> Diff:
+    def revert_hunk_line(line: HunkLine) -> HunkLine:
+        match line:
+            case InsertedLine(content):
+                return DeletedLine(content)
+            case DeletedLine(content):
+                return InsertedLine(content)
+        return line
+
+    def revert_hunk(hunk: Hunk) -> Hunk:
+        return Hunk(
+            old_start_at=hunk.old_start_at,
+            new_start_at=hunk.new_start_at,
+            lines=[revert_hunk_line(line) for line in hunk.lines],
+        )
+
+    def revert_file_hunk(file_hunk: FileHunk) -> FileHunk:
+        return FileHunk(
+            old_filename=file_hunk.old_filename,
+            new_filename=file_hunk.new_filename,
+            hunk=revert_hunk(file_hunk.hunk),
+        )
+
+    return Diff.from_file_hunks([
+        revert_file_hunk(file_hunk) for file_hunk in list(diff.file_hunks)
+    ])
+
+
 def statements_in_function(
     index: kaskara.analysis.Analysis,
     function: kaskara.functions.Function,

From b2161a3d0b2b6dbee63bb48b4471d5adf19e6db8 Mon Sep 17 00:00:00 2001
From: ChrisTimperley <christimperley@googlemail.com>
Date: Mon, 15 Jul 2024 23:58:13 -0400
Subject: [PATCH 2/3] added super basic test that isn't sufficient

---
 test/integration/test_util.py | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/test/integration/test_util.py b/test/integration/test_util.py
index 4338729..fff42bc 100644
--- a/test/integration/test_util.py
+++ b/test/integration/test_util.py
@@ -1,6 +1,9 @@
 import typing as t
 
-from repairchain.util import statements_in_function
+from repairchain.util import (
+    revert_diff,
+    statements_in_function,
+)
 
 
 if t.TYPE_CHECKING:
@@ -9,6 +12,18 @@
     from repairchain.indexer import KaskaraIndexer
 
 
+def test_revert_diff(
+    example_project_factory,
+) -> None:
+    with example_project_factory("mock-cp") as project:
+        repo = project.repository
+        original_implicated_diff = project.original_implicated_diff
+        triggering_commit = project.triggering_commit
+        triggering_commit_parent = triggering_commit.parents[0]
+
+        assert revert_diff(revert_diff(original_implicated_diff)) == original_implicated_diff
+
+
 def test_statements_in_function(
     example_project_factory,
 ) -> None:

From aa213da0bfd952ab15c6da74bde24afca9dd6d9d Mon Sep 17 00:00:00 2001
From: ChrisTimperley <christimperley@googlemail.com>
Date: Tue, 16 Jul 2024 00:48:46 -0400
Subject: [PATCH 3/3] updated reverse diff generation

---
 src/repairchain/strategies/generation/reversion.py | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/src/repairchain/strategies/generation/reversion.py b/src/repairchain/strategies/generation/reversion.py
index d6f9198..cb6d64c 100644
--- a/src/repairchain/strategies/generation/reversion.py
+++ b/src/repairchain/strategies/generation/reversion.py
@@ -17,7 +17,7 @@
 from repairchain.models.diff import Diff
 from repairchain.models.patch_outcome import PatchOutcome
 from repairchain.strategies.generation.base import PatchGenerationStrategy
-from repairchain.util import dd_minimize
+from repairchain.util import dd_minimize, revert_diff
 
 if t.TYPE_CHECKING:
     from sourcelocation.diff import FileHunk
@@ -80,12 +80,7 @@ def _cleanup(self, restore_to: str) -> None:
 
     def _compute_reverse_diff(self) -> Diff:
         """Computes a diff that reverses the changes introduced by the triggering commit."""
-        unidiff = self.project.repository.git.diff(
-            self.triggering_commit,
-            self.triggering_commit_parent,
-            unified=True,
-        )
-        return Diff.from_unidiff(unidiff).strip(1)
+        return revert_diff(self.project.original_implicated_diff)
 
     def _minimize_reverse_diff(self, reverse_diff: Diff) -> Diff:
         """Minimizes the reverse diff to the smallest possible diff that still undoes the triggering commit."""