Add regex command implementation

tests/integration/regex_undo_test.go

@@ -0,0 +1,42 @@
+package integration
+
+import (
+	"bytes"
+	"path/filepath"
+	"testing"
+
+	renamercmd "github.com/rogeecn/renamer/cmd"
+)
+
+func TestRegexUndoRestoresAutomationRun(t *testing.T) {
+	t.Parallel()
+
+	tmp := t.TempDir()
+	copyRegexFixtureIntegration(t, "mixed", tmp)
+
+	apply := renamercmd.NewRootCommand()
+	var applyOut bytes.Buffer
+	apply.SetOut(&applyOut)
+	apply.SetErr(&applyOut)
+	apply.SetArgs([]string{"regex", "^build_(\\d+)_(.*)$", "release-@1-@2", "--yes", "--path", tmp})
+	if err := apply.Execute(); err != nil {
+		t.Fatalf("regex apply failed: %v\noutput: %s", err, applyOut.String())
+	}
+
+	if !fileExistsTestHelper(filepath.Join(tmp, "release-101-release.tar.gz")) || !fileExistsTestHelper(filepath.Join(tmp, "release-102-hotfix.tar.gz")) {
+		t.Fatalf("expected renamed files after apply")
+	}
+
+	undo := renamercmd.NewRootCommand()
+	var undoOut bytes.Buffer
+	undo.SetOut(&undoOut)
+	undo.SetErr(&undoOut)
+	undo.SetArgs([]string{"undo", "--path", tmp})
+	if err := undo.Execute(); err != nil {
+		t.Fatalf("undo failed: %v\noutput: %s", err, undoOut.String())
+	}
+
+	if !fileExistsTestHelper(filepath.Join(tmp, "build_101_release.tar.gz")) || !fileExistsTestHelper(filepath.Join(tmp, "build_102_hotfix.tar.gz")) {
+		t.Fatalf("expected originals restored after undo")
+	}
+}