logger_test.go

package main

import (
	"bytes"
	"errors"
	"io"
	"net/http"
	"testing"

	"github.com/stretchr/testify/suite"
	"go.uber.org/fx"
	"go.uber.org/fx/fxtest"
)

type testLogger struct {
	t *testing.T

	suiteName string
	testName  string
}

func (tl testLogger) Printf(format string, args ...interface{}) {
	tl.t.Logf(
		"[%s] [%s] "+format+"\n",
		append(
			[]interface{}{tl.suiteName, tl.testName},
			args...,
		)...,
	)
}

type LoggerSuite struct {
	suite.Suite

	capture *bytes.Buffer
}

var _ suite.SetupTestSuite = (*LoggerSuite)(nil)

func (suite *LoggerSuite) SetupTest() {
	suite.capture = new(bytes.Buffer)
}

func (suite *LoggerSuite) TestWriterLogger() {
	wl := WriterLogger{Writer: suite.capture}
	wl.Printf("test: %d", 123)
	suite.Equal("test: 123\n", suite.capture.String())
}

func (suite *LoggerSuite) TestWriterLoggerError() {
	r, w := io.Pipe()
	r.Close()
	w.Close()

	wl := WriterLogger{Writer: w}
	suite.Panics(func() {
		wl.Printf("test: %d", 123)
	})
}

func (suite *LoggerSuite) TestDiscardLogger() {
	DiscardLogger{}.Printf("test: %d", 123)
}

func (suite *LoggerSuite) TestProvideLogger() {
	var l Logger
	app := fxtest.New(
		suite.T(),
		fx.Logger(DiscardLogger{}),
		provideLogger(suite.capture),
		fx.Populate(&l),
	)

	app.RequireStart()
	app.RequireStop()

	suite.Require().NotNil(l)
	l.Printf("test: %d", 123)
	suite.Equal("test: 123\n", suite.capture.String())
}

func (suite *LoggerSuite) TestLogServerError() {
	suite.Run("ErrServerClosed", func() {
		suite.capture.Reset()
		l := WriterLogger{Writer: suite.capture}
		logServerError(l, http.ErrServerClosed)
		suite.Empty(suite.capture.String())
	})

	suite.Run("UnexpectedError", func() {
		suite.capture.Reset()
		l := WriterLogger{Writer: suite.capture}
		logServerError(l, errors.New("unexpected error"))
		suite.NotEmpty(suite.capture.String())
	})
}

func TestLogger(t *testing.T) {
	suite.Run(t, new(LoggerSuite))
}