Fix file rename handling in git

CHANGELOG.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## v0.6.6
+
+### Fixed
+
+- File renames were not handled correctly when running `git ci` on branches with
+  multiple commits.
+
 ## v0.6.5
 
 ### Added

internal/discovery/git_branch.go

@@ -27,7 +27,7 @@ func (gd GitBranchFileFinder) Find(pattern ...string) (FileFindResults, error) {
 
 	log.Debug().Str("from", cr.From).Str("to", cr.To).Msg("Got commit range from git")
 
-	out, err := gd.gitCmd("log", "--no-merges", "--pretty=format:%H", "--name-status", "--diff-filter=d", cr.String())
+	out, err := gd.gitCmd("log", "--reverse", "--no-merges", "--pretty=format:%H", "--name-status", "--diff-filter=d", cr.String())
 	if err != nil {
 		return nil, err
 	}
@@ -42,19 +42,29 @@ func (gd GitBranchFileFinder) Find(pattern ...string) (FileFindResults, error) {
 		if len(parts) == 1 && parts[0] != "" {
 			commit = parts[0]
 		} else if len(parts) >= 2 {
-			path := parts[len(parts)-1]
+			op := parts[0]
+			srcPath := parts[1]
+			dstPath := parts[len(parts)-1]
 			log.Debug().
-				Str("path", path).
+				Str("path", dstPath).
 				Str("commit", commit).
-				Bool("allowed", gd.isPathAllowed(path)).
+				Bool("allowed", gd.isPathAllowed(dstPath)).
 				Msg("Git file change")
-			if !gd.isPathAllowed(path) {
+			if !gd.isPathAllowed(dstPath) {
 				continue
 			}
-			if _, ok := results.pathCommits[path]; !ok {
-				results.pathCommits[path] = []string{}
+			if _, ok := results.pathCommits[dstPath]; !ok {
+				results.pathCommits[dstPath] = []string{}
 			}
-			results.pathCommits[path] = append(results.pathCommits[path], commit)
+			// check if we're dealing with a rename and if so we need to
+			// rename results in pathCommits
+			if strings.HasPrefix(op, "R") {
+				if v, ok := results.pathCommits[srcPath]; ok {
+					results.pathCommits[dstPath] = append(results.pathCommits[dstPath], v...)
+					delete(results.pathCommits, srcPath)
+				}
+			}
+			results.pathCommits[dstPath] = append(results.pathCommits[dstPath], commit)
 		}
 	}
 

internal/discovery/git_branch_test.go

@@ -96,6 +96,31 @@ C50     foo/bar/cp1.txt         foo/cp1.del
 				{Path: "foo/1.txt", Commits: []string{"commit1"}},
 			},
 		},
+		{
+			detector: discovery.NewGitBranchFileFinder(func(args ...string) ([]byte, error) {
+				if args[0] == "rev-list" {
+					return []byte("commit1\ncommit3\n"), nil
+				}
+				content := `commit1
+M       file1
+M       file2
+
+commit2
+M       file1
+M       file3
+
+commit3
+R100    file1  file4
+M       file2
+`
+				return []byte([]byte(content)), nil
+			}, nil, "main"),
+			output: []discovery.File{
+				{Path: "file2", Commits: []string{"commit1", "commit3"}},
+				{Path: "file3", Commits: []string{"commit2"}},
+				{Path: "file4", Commits: []string{"commit1", "commit2", "commit3"}},
+			},
+		},
 	}
 
 	for i, tc := range testCases {