Add regex command implementation

tests/contract/regex_ledger_test.go

@@ -0,0 +1,62 @@
+package contract
+
+import (
+	"bytes"
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"testing"
+
+	renamercmd "github.com/rogeecn/renamer/cmd"
+	"github.com/rogeecn/renamer/internal/history"
+)
+
+func TestRegexCommandLedgerMetadata(t *testing.T) {
+	tmp := t.TempDir()
+	copyRegexFixture(t, "mixed", tmp)
+
+	cmd := renamercmd.NewRootCommand()
+	var out bytes.Buffer
+	cmd.SetOut(&out)
+	cmd.SetErr(&out)
+	cmd.SetArgs([]string{"regex", "^build_(\\d+)_(.*)$", "release-@1-@2", "--yes", "--path", tmp})
+
+	if err := cmd.Execute(); err != nil {
+		t.Fatalf("regex apply command failed: %v\noutput: %s", err, out.String())
+	}
+
+	ledgerPath := filepath.Join(tmp, ".renamer")
+	data, err := os.ReadFile(ledgerPath)
+	if err != nil {
+		t.Fatalf("read ledger: %v", err)
+	}
+
+	lines := bytes.Split(bytes.TrimSpace(data), []byte("\n"))
+	if len(lines) == 0 {
+		t.Fatalf("expected ledger entries written")
+	}
+
+	var entry history.Entry
+	if err := json.Unmarshal(lines[len(lines)-1], &entry); err != nil {
+		t.Fatalf("decode ledger entry: %v", err)
+	}
+
+	if entry.Command != "regex" {
+		t.Fatalf("expected regex command recorded, got %q", entry.Command)
+	}
+
+	if entry.Metadata["pattern"] != "^build_(\\d+)_(.*)$" {
+		t.Fatalf("unexpected pattern metadata: %#v", entry.Metadata["pattern"])
+	}
+	if entry.Metadata["template"] != "release-@1-@2" {
+		t.Fatalf("unexpected template metadata: %#v", entry.Metadata["template"])
+	}
+
+	if toFloat(entry.Metadata["matched"]) != 2 || toFloat(entry.Metadata["changed"]) != 2 {
+		t.Fatalf("unexpected match/change counts: %#v", entry.Metadata)
+	}
+
+	if len(entry.Operations) != 2 {
+		t.Fatalf("expected 2 operations, got %d", len(entry.Operations))
+	}
+}