add tests for pidfile

pidfile/pidfile.go

@@ -44,11 +44,13 @@ func Create(pidfile string) error {
 }
 
 // Remove pidfile
-func Remove(pidfile string) {
+func Remove(pidfile string) error {
 	if pidfile == "" {
-		return
+		return nil
 	}
-	if err := os.Remove(pidfile); err != nil {
+	err := os.Remove(pidfile)
+	if err != nil {
 		logger.Errorf("Failed to remove the pidfile: %s: %s", pidfile, err)
 	}
+	return err
 }

pidfile/pidfile_test.go

@@ -0,0 +1,61 @@
+// +build !windows
+
+package pidfile
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strconv"
+	"testing"
+)
+
+func TestCreate(t *testing.T) {
+	err := Create("")
+	if err != nil {
+		t.Errorf("err should be nil but: %v", err)
+	}
+
+	dir, err := ioutil.TempDir("", "")
+	if err != nil {
+		t.Fatalf("failed to create tempdir")
+	}
+	defer os.RemoveAll(dir)
+	pidfile := filepath.Join(dir, "pidfile")
+	err = Create(pidfile)
+	if err != nil {
+		t.Errorf("err should be nil but: %v", err)
+	}
+	pidString, _ := ioutil.ReadFile(pidfile)
+	pid, _ := strconv.Atoi(string(pidString))
+	if pid != os.Getpid() {
+		t.Errorf("contents of pidfile does not match pid. content: %d, pid: %d", pid, os.Getpid())
+	}
+
+	err = Create(pidfile)
+	if err == nil {
+		t.Errorf("Successfully overwriting the pidfile unintentionally")
+	}
+}
+
+func TestRemove(t *testing.T) {
+	err := Remove("")
+	if err != nil {
+		t.Errorf("err should be nil but: %v", err)
+	}
+	dir, err := ioutil.TempDir("", "")
+	if err != nil {
+		t.Fatalf("failed to create tempdir")
+	}
+	defer os.RemoveAll(dir)
+	pidfile := filepath.Join(dir, "pidfile")
+	err = Create(pidfile)
+	if err != nil {
+		t.Errorf("err should be nil but: %v", err)
+	}
+
+	err = Remove(pidfile)
+	if err != nil {
+		t.Errorf("err should be nil but: %v", err)
+	}
+}