Properly handle all diff cases

aider/commands.py

@@ -230,7 +230,7 @@ class Commands:
             return
 
         commits = f"{self.coder.last_aider_commit_hash}~1"
-        diff = self.coder.repo.get_diffs(
+        diff = self.coder.repo.diff_commits(
             self.coder.pretty,
             commits,
             self.coder.last_aider_commit_hash,

aider/repo.py

@@ -56,12 +56,7 @@ class GitRepo:
         if message:
             commit_message = message
         else:
-            diff_args = []
-            if fnames:
-                diff_args += ["--"] + list(fnames)
-            dump(diff_args)
-            diffs = self.get_diffs(False, *diff_args)
-            dump(diffs)
+            diffs = self.get_diffs(fnames)
             commit_message = self.get_commit_message(diffs, context)
 
         if not commit_message:
@@ -129,42 +124,38 @@ class GitRepo:
 
         return commit_message
 
-    def get_diffs(self, pretty, *args):
-        args = list(args)
-
-        # if args are specified, just add --pretty if needed
-        if args:
-            if pretty:
-                args = ["--color"] + args
-            dump(args)
-            return self.repo.git.diff(*args)
-
-        # otherwise, we always want diffs of index and working dir
-
+    def get_diffs(self, fnames=None):
+        # We always want diffs of index and working dir
         try:
             commits = self.repo.iter_commits(self.repo.active_branch)
             current_branch_has_commits = any(commits)
         except git.exc.GitCommandError:
             current_branch_has_commits = False
 
-        if pretty:
-            args = ["--color"]
+        if not fnames:
+            fnames = []
 
         if current_branch_has_commits:
-            # if there is a HEAD, just diff against it to pick up index + working
-            args += ["HEAD"]
+            args = ["HEAD", "--"] + list(fnames)
             return self.repo.git.diff(*args)
 
-        # diffs in the index
-        diffs = self.repo.git.diff(*(args + ["--cached"]))
-        # plus, diffs in the working dir
-        diffs += self.repo.git.diff(*args)
+        wd_args = ["--"] + list(fnames)
+        index_args = ["--cached"] + wd_args
+
+        diffs = self.repo.git.diff(*index_args)
+        diffs += self.repo.git.diff(*wd_args)
 
         return diffs
 
-    def show_diffs(self, pretty):
-        diffs = self.get_diffs(pretty)
-        print(diffs)
+    def diff_commits(self, pretty, from_commit, to_commit):
+        args = []
+        if pretty:
+            args += ["--color"]
+
+        args += [from_commit, to_commit]
+        diffs = self.repo.git.diff(*args)
+
+        return diffs
 
     def get_tracked_files(self):
         if not self.repo:

tests/test_repo.py

@@ -26,7 +26,7 @@ class TestRepo(unittest.TestCase):
             fname.write_text("workingdir\n")
 
             git_repo = GitRepo(InputOutput(), None, ".")
-            diffs = git_repo.get_diffs(False)
+            diffs = git_repo.get_diffs()
             self.assertIn("index", diffs)
             self.assertIn("workingdir", diffs)
 
@@ -49,7 +49,7 @@ class TestRepo(unittest.TestCase):
             fname2.write_text("workingdir\n")
 
             git_repo = GitRepo(InputOutput(), None, ".")
-            diffs = git_repo.get_diffs(False)
+            diffs = git_repo.get_diffs()
             self.assertIn("index", diffs)
             self.assertIn("workingdir", diffs)
 
@@ -67,7 +67,7 @@ class TestRepo(unittest.TestCase):
             repo.git.commit("-m", "second")
 
             git_repo = GitRepo(InputOutput(), None, ".")
-            diffs = git_repo.get_diffs(False, ["HEAD~1", "HEAD"])
+            diffs = git_repo.diff_commits(False, "HEAD~1", "HEAD")
             dump(diffs)
             self.assertIn("two", diffs)