dozzle/internal/docker/event_generator_test.go

package docker

import (
	"bufio"
	"bytes"
	"encoding/binary"
	"reflect"
	"strings"
	"sync"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestEventGenerator_Events_tty(t *testing.T) {
	input := "example input"
	reader := bufio.NewReader(strings.NewReader(input))

	g := NewEventGenerator(reader, true)
	event := <-g.Events

	require.NotNil(t, event, "Expected event to not be nil, but got nil")
	assert.Equal(t, input, event.Message)
}

func TestEventGenerator_Events_non_tty(t *testing.T) {
	input := "example input"
	reader := bytes.NewReader(makeMessage(input, STDOUT))

	g := NewEventGenerator(reader, false)
	event := <-g.Events

	require.NotNil(t, event, "Expected event to not be nil, but got nil")
	assert.Equal(t, input, event.Message)
}

func TestEventGenerator_Events_non_tty_close_channel(t *testing.T) {
	input := "example input"
	reader := bytes.NewReader(makeMessage(input, STDOUT))

	g := NewEventGenerator(reader, false)
	<-g.Events
	_, ok := <-g.Events

	assert.False(t, ok, "Expected channel to be closed")
}

func TestEventGenerator_Events_routines_done(t *testing.T) {
	input := "example input"
	reader := bytes.NewReader(makeMessage(input, STDOUT))

	g := NewEventGenerator(reader, false)
	<-g.Events
	assert.False(t, waitTimeout(&g.wg, 1*time.Second), "Expected routines to be done")
}

func makeMessage(message string, stream StdType) []byte {
	data := make([]byte, 8)
	binary.BigEndian.PutUint32(data[4:], uint32(len(message)))
	data[0] = byte(stream / 2)
	data = append(data, []byte(message)...)

	return data
}

func waitTimeout(wg *sync.WaitGroup, timeout time.Duration) bool {
	c := make(chan struct{})
	go func() {
		defer close(c)
		wg.Wait()
	}()
	select {
	case <-c:
		return false // completed normally
	case <-time.After(timeout):
		return true // timed out
	}
}

func Test_createEvent(t *testing.T) {
	type args struct {
		message string
	}
	tests := []struct {
		name string
		args args
		want *LogEvent
	}{
		{
			name: "empty message",
			args: args{
				message: "",
			},
			want: &LogEvent{
				Message: "",
			},
		}, {
			name: "simple json message",
			args: args{
				message: "2020-05-13T18:55:37.772853839Z {\"key\": \"value\"}",
			},
			want: &LogEvent{
				Message: map[string]interface{}{
					"key": "value",
				},
			},
		},
		{
			name: "invalid json message",
			args: args{
				message: "2020-05-13T18:55:37.772853839Z {\"key\"}",
			},
			want: &LogEvent{
				Message: "{\"key\"}",
			},
		},
		{
			name: "invalid json message",
			args: args{
				message: "2020-05-13T18:55:37.772853839Z 123",
			},
			want: &LogEvent{
				Message: "123",
			},
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if got := createEvent(tt.args.message, STDOUT); !reflect.DeepEqual(got.Message, tt.want.Message) {
				t.Errorf("createEvent() = %v, want %v", got.Message, tt.want.Message)
			}
		})
	}
}

type mockReadCloser struct {
	bytes []byte
}

func (m mockReadCloser) Read(p []byte) (int, error) {
	return copy(p, m.bytes), nil
}

func Benchmark_readEvent(b *testing.B) {
	b.ReportAllocs()

	data := makeMessage("2020-05-13T18:55:37.772853839Z {\"key\": \"value\"}\n", STDOUT)

	reader := bufio.NewReader(mockReadCloser{bytes: data})

	for i := 0; i < b.N; i++ {
		readEvent(reader, true)
	}
}