logrotate_test.go

//go:build windows || darwin

package logrotate

import (
	"os"
	"path/filepath"
	"strconv"
	"testing"
)

func TestRotate(t *testing.T) {
	logDir := t.TempDir()
	logFile := filepath.Join(logDir, "testlog.log")

	// No log exists
	Rotate(logFile)

	if err := os.WriteFile(logFile, []byte("1"), 0o644); err != nil {
		t.Fatal(err)
	}
	if _, err := os.Stat(logFile); os.IsNotExist(err) {
		t.Fatal("expected log file to exist")
	}

	// First rotation
	Rotate(logFile)
	if _, err := os.Stat(filepath.Join(logDir, "testlog-1.log")); os.IsNotExist(err) {
		t.Fatal("expected rotated log file to exist")
	}
	if _, err := os.Stat(filepath.Join(logDir, "testlog-2.log")); !os.IsNotExist(err) {
		t.Fatal("expected no second rotated log file")
	}
	if _, err := os.Stat(logFile); !os.IsNotExist(err) {
		t.Fatal("expected original log file to be moved")
	}

	// Should be a no-op without a new log
	Rotate(logFile)
	if _, err := os.Stat(filepath.Join(logDir, "testlog-1.log")); os.IsNotExist(err) {
		t.Fatal("expected rotated log file to still exist")
	}
	if _, err := os.Stat(filepath.Join(logDir, "testlog-2.log")); !os.IsNotExist(err) {
		t.Fatal("expected no second rotated log file")
	}
	if _, err := os.Stat(logFile); !os.IsNotExist(err) {
		t.Fatal("expected no original log file")
	}

	for i := 2; i <= MaxLogFiles+1; i++ {
		if err := os.WriteFile(logFile, []byte(strconv.Itoa(i)), 0o644); err != nil {
			t.Fatal(err)
		}
		if _, err := os.Stat(logFile); os.IsNotExist(err) {
			t.Fatal("expected log file to exist")
		}
		Rotate(logFile)
		if _, err := os.Stat(logFile); !os.IsNotExist(err) {
			t.Fatal("expected log file to be moved")
		}
		for j := 1; j < i; j++ {
			if _, err := os.Stat(filepath.Join(logDir, "testlog-"+strconv.Itoa(j)+".log")); os.IsNotExist(err) {
				t.Fatalf("expected rotated log file %d to exist", j)
			}
		}
		if _, err := os.Stat(filepath.Join(logDir, "testlog-"+strconv.Itoa(i+1)+".log")); !os.IsNotExist(err) {
			t.Fatalf("expected no rotated log file %d", i+1)
		}
	}
}