writer_test.go

// Copyright (c) 2016 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

package zap

import (
	"bytes"
	"errors"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"github.com/uber-go/zap/spywrite"
)

type testBuffer struct {
	*bytes.Buffer
}

func newTestBuffer() testBuffer {
	return testBuffer{&bytes.Buffer{}}
}

func (t testBuffer) Sync() error {
	return nil
}

func requireWriteWorks(t testing.TB, ws WriteSyncer) {
	n, err := ws.Write([]byte("foo"))
	require.NoError(t, err, "Unexpected error writing to WriteSyncer.")
	require.Equal(t, 3, n, "Wrote an unexpected number of bytes.")
}

func TestAddSyncWriteSyncer(t *testing.T) {
	buf := &bytes.Buffer{}
	concrete := &spywrite.WriteSyncer{Writer: buf}
	ws := AddSync(concrete)
	requireWriteWorks(t, ws)

	require.NoError(t, ws.Sync(), "Unexpected error syncing a WriteSyncer.")
	require.True(t, concrete.Called(), "Expected to dispatch to concrete type's Sync method.")

	concrete.SetError(errors.New("fail"))
	assert.Error(t, ws.Sync(), "Expected to propagate errors from concrete type's Sync method.")
}

func TestAddSyncWriteFlusher(t *testing.T) {
	buf := &bytes.Buffer{}
	concrete := &spywrite.WriteFlusher{Writer: buf}
	ws := AddSync(concrete)
	requireWriteWorks(t, ws)

	require.NoError(t, ws.Sync(), "Unexpected error syncing a WriteSyncer.")
	require.True(t, concrete.Called(), "Expected to dispatch to concrete type's Flush method.")

	concrete.SetError(errors.New("fail"))
	assert.Error(t, ws.Sync(), "Expected to propagate errors from concrete type's Flush method.")
}

func TestAddSyncWriteFlushSyncer(t *testing.T) {
	buf := &bytes.Buffer{}
	concrete := &spywrite.WriteFlushSyncer{Writer: buf}
	ws := AddSync(concrete)
	requireWriteWorks(t, ws)

	require.NoError(t, ws.Sync(), "Unexpected error syncing a WriteSyncer.")
	require.True(t, concrete.Syncer.Called(), "Expected to delegate to concrete type's Sync method.")
	require.False(t, concrete.Flusher.Called(), "Unexpected use of concrete type's Flush method.")

	concrete.Syncer.SetError(errors.New("fail sync"))
	concrete.Flusher.SetError(nil)
	assert.Error(t, ws.Sync(), "Expected to propagate errors from concrete type's Sync method.")

	concrete.Syncer.SetError(nil)
	concrete.Flusher.SetError(errors.New("flush sync"))
	assert.NoError(t, ws.Sync(), "Errors in concrete type's Flush method shouldn't affect wrapper's Sync.")
}

func TestAddSyncWriter(t *testing.T) {
	// If we pass a plain io.Writer, make sure that we still get a WriteSyncer
	// with a no-op Sync.
	buf := &bytes.Buffer{}
	ws := AddSync(buf)
	requireWriteWorks(t, ws)
	assert.NoError(t, ws.Sync(), "Unexpected error calling a no-op Sync method.")
}