// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package errcapture

import (
	"errors"
	"io"
	"testing"
)

type testCloser struct {
	err error
}

func (c testCloser) Close() error {
	return c.err
}

func TestDo(t *testing.T) {
	for _, tcase := range []struct {
		err    error
		closer io.Closer

		expectedErrStr string
	}{
		{
			err:            nil,
			closer:         testCloser{err: nil},
			expectedErrStr: "",
		},
		{
			err:            errors.New("test"),
			closer:         testCloser{err: nil},
			expectedErrStr: "test",
		},
		{
			err:            nil,
			closer:         testCloser{err: errors.New("test")},
			expectedErrStr: "1 error(s) occurred:\n* close: test",
		},
		{
			err:            errors.New("test"),
			closer:         testCloser{err: errors.New("test")},
			expectedErrStr: "2 error(s) occurred:\n* test\n* close: test",
		},
	} {
		if ok := t.Run("", func(t *testing.T) {
			ret := tcase.err
			Do(&ret, tcase.closer.Close, "close")

			if tcase.expectedErrStr == "" {
				if ret != nil {
					t.Error("Expected error to be nil")
					t.Fail()
				}
			} else {
				if ret == nil {
					t.Error("Expected error to be not nil")
					t.Fail()
				}

				if tcase.expectedErrStr != ret.Error() {
					t.Errorf("%s != %s", tcase.expectedErrStr, ret.Error())
					t.Fail()
				}
			}
		}); !ok {
			return
		}
	}
}