From aedcf87338bc66df6cf03bfc101e63bf5d66cf01 Mon Sep 17 00:00:00 2001
From: Lukasz Raczylo <lukasz@raczylo.com>
Date: Tue, 16 Dec 2025 19:11:25 +0000
Subject: [PATCH] Ignore file rename / remove operations as they don't
 contribute to the codebase. (#1)

---
 internal/diff/analyzer.go      |  7 +++++++
 internal/diff/analyzer_test.go | 35 ++++++++++++++++++++++++++++++++++
 internal/git/repository.go     |  5 +++++
 3 files changed, 47 insertions(+)

diff --git a/internal/diff/analyzer.go b/internal/diff/analyzer.go
index f0b8e11..f93c59c 100644
--- a/internal/diff/analyzer.go
+++ b/internal/diff/analyzer.go
@@ -63,3 +63,10 @@ func IsDocumentationFile(filename string) bool {
 func IsMeaningfulLine(line string) bool {
 	return !IsWhitespaceLine(line) && !IsCommentLine(line)
 }
+
+// IsRenameOrMove checks if a file change represents a rename or move operation
+// rather than actual content modification. A rename/move is detected when both
+// the source (fromName) and destination (toName) paths exist and differ.
+func IsRenameOrMove(fromName, toName string) bool {
+	return fromName != "" && toName != "" && fromName != toName
+}
diff --git a/internal/diff/analyzer_test.go b/internal/diff/analyzer_test.go
index 4da20cc..f90480b 100644
--- a/internal/diff/analyzer_test.go
+++ b/internal/diff/analyzer_test.go
@@ -167,3 +167,38 @@ func TestIsMeaningfulLine(t *testing.T) {
 		})
 	}
 }
+
+func TestIsRenameOrMove(t *testing.T) {
+	tests := []struct {
+		name     string
+		fromName string
+		toName   string
+		expected bool
+	}{
+		// Rename/move operations - should return true
+		{"simple rename", "old.go", "new.go", true},
+		{"move to subdirectory", "file.go", "pkg/file.go", true},
+		{"move from subdirectory", "pkg/file.go", "file.go", true},
+		{"rename in subdirectory", "pkg/old.go", "pkg/new.go", true},
+		{"move between directories", "src/file.go", "lib/file.go", true},
+		{"complex path rename", "internal/api/v1/handler.go", "internal/api/v2/handler.go", true},
+
+		// NOT rename/move - should return false
+		{"new file", "", "new.go", false},
+		{"deleted file", "old.go", "", false},
+		{"modify same file", "file.go", "file.go", false},
+		{"both empty", "", "", false},
+		{"same path different case is not rename", "File.go", "File.go", false},
+
+		// Edge cases
+		{"whitespace in path rename", "my file.go", "my-file.go", true},
+		{"deeply nested rename", "a/b/c/d/e/f.go", "a/b/c/d/e/g.go", true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := IsRenameOrMove(tt.fromName, tt.toName)
+			assert.Equal(t, tt.expected, result, "IsRenameOrMove(%q, %q)", tt.fromName, tt.toName)
+		})
+	}
+}
diff --git a/internal/git/repository.go b/internal/git/repository.go
index 4531616..94785bf 100644
--- a/internal/git/repository.go
+++ b/internal/git/repository.go
@@ -397,6 +397,11 @@ func (r *Repository) getCommitStats(c *object.Commit, testPatterns []string) com
 	filesSet := make(map[string]bool)
 
 	for _, change := range changes {
+		// Skip rename/move operations - they don't represent actual code contribution
+		if diff.IsRenameOrMove(change.From.Name, change.To.Name) {
+			continue
+		}
+
 		// Get the file path
 		var filePath string
 		if change.To.Name != "" {