File: retry_test.go

package info (click to toggle)
golang-google-api 0.0~git20161128.3cc2e59-2
  • links: PTS, VCS
  • area: main
  • in suites: stretch, stretch-backports
  • size: 64,468 kB
  • ctags: 71,262
  • sloc: makefile: 16
file content (162 lines) | stat: -rw-r--r-- 4,054 bytes parent folder | download | duplicates (3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
package gensupport

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

	"golang.org/x/net/context"
)

func TestRetry(t *testing.T) {
	testCases := []struct {
		desc       string
		respStatus []int // HTTP status codes returned (length indicates number of calls we expect).
		maxRetry   int   // Max number of calls allowed by the BackoffStrategy.
		wantStatus int   // StatusCode of returned response.
	}{
		{
			desc:       "First call successful",
			respStatus: []int{200},
			maxRetry:   3,
			wantStatus: 200,
		},
		{
			desc:       "Retry before success",
			respStatus: []int{500, 500, 500, 200},
			maxRetry:   3,
			wantStatus: 200,
		},
		{
			desc:       "Backoff strategy abandons after 3 retries",
			respStatus: []int{500, 500, 500, 500},
			maxRetry:   3,
			wantStatus: 500,
		},
		{
			desc:       "Backoff strategy abandons after 2 retries",
			respStatus: []int{500, 500, 500},
			maxRetry:   2,
			wantStatus: 500,
		},
	}
	for _, tt := range testCases {
		// Function consumes tt.respStatus
		f := func() (*http.Response, error) {
			if len(tt.respStatus) == 0 {
				return nil, errors.New("too many requests to function")
			}
			resp := &http.Response{StatusCode: tt.respStatus[0]}
			tt.respStatus = tt.respStatus[1:]
			return resp, nil
		}

		backoff := &LimitRetryStrategy{
			Max:      tt.maxRetry,
			Strategy: NoPauseStrategy,
		}

		resp, err := Retry(nil, f, backoff)
		if err != nil {
			t.Errorf("%s: Retry returned err %v", tt.desc, err)
		}
		if got := resp.StatusCode; got != tt.wantStatus {
			t.Errorf("%s: Retry returned response with StatusCode=%d; want %d", got, tt.wantStatus)
		}
		if len(tt.respStatus) != 0 {
			t.Errorf("%s: f was not called enough; status codes remaining: %v", tt.desc, tt.respStatus)
		}
	}
}

type checkCloseReader struct {
	closed bool
}

func (c *checkCloseReader) Read(p []byte) (n int, err error) { return 0, io.EOF }
func (c *checkCloseReader) Close() error {
	c.closed = true
	return nil
}

func TestRetryClosesBody(t *testing.T) {
	var i int
	responses := []*http.Response{
		{StatusCode: 500, Body: &checkCloseReader{}},
		{StatusCode: 500, Body: &checkCloseReader{}},
		{StatusCode: 200, Body: &checkCloseReader{}},
	}
	f := func() (*http.Response, error) {
		resp := responses[i]
		i++
		return resp, nil
	}

	resp, err := Retry(nil, f, NoPauseStrategy)
	if err != nil {
		t.Fatalf("Retry returned error: %v", err)
	}
	if resp != responses[2] {
		t.Errorf("Retry returned %v; want %v", resp, responses[2])
	}
	for i, resp := range responses {
		want := i != 2 // Only the last response should not be closed.
		got := resp.Body.(*checkCloseReader).closed
		if got != want {
			t.Errorf("response[%d].Body closed = %t, want %t", got, want)
		}
	}
}

func RetryReturnsOnContextCancel(t *testing.T) {
	f := func() (*http.Response, error) {
		return nil, io.ErrUnexpectedEOF
	}
	backoff := UniformPauseStrategy(time.Hour)
	ctx, cancel := context.WithCancel(context.Background())

	errc := make(chan error, 1)
	go func() {
		_, err := Retry(ctx, f, backoff)
		errc <- err
	}()

	cancel()
	select {
	case err := <-errc:
		if err != ctx.Err() {
			t.Errorf("Retry returned err: %v, want %v", err, ctx.Err())
		}
	case <-time.After(5 * time.Second):
		t.Errorf("Timed out waiting for Retry to return")
	}
}

func TestShouldRetry(t *testing.T) {
	testCases := []struct {
		status int
		err    error
		want   bool
	}{
		{status: 200, want: false},
		{status: 308, want: false},
		{status: 403, want: false},
		{status: 429, want: true},
		{status: 500, want: true},
		{status: 503, want: true},
		{status: 600, want: false},
		{err: io.EOF, want: false},
		{err: errors.New("random badness"), want: false},
		{err: io.ErrUnexpectedEOF, want: true},
		{err: &net.AddrError{}, want: false},              // Not temporary.
		{err: &net.DNSError{IsTimeout: true}, want: true}, // Temporary.
	}
	for _, tt := range testCases {
		if got := shouldRetry(tt.status, tt.err); got != tt.want {
			t.Errorf("shouldRetry(%d, %v) = %t; want %t", tt.status, tt.err, got, tt.want)
		}
	}
}