metrics: unit tests for callback Gauges
Peter Bourgon
8 years ago
| 0 | 0 | package expvar_test |
| 1 | 1 | |
| 2 | 2 | import ( |
| 3 | stdexpvar "expvar" | |
| 4 | "fmt" | |
| 3 | 5 | "testing" |
| 4 | 6 | |
| 5 | 7 | "github.com/peterbourgon/gokit/metrics/expvar" |
| 15 | 17 | teststat.PopulateNormalHistogram(t, h, seed, mean, stdev) |
| 16 | 18 | teststat.AssertExpvarNormalHistogram(t, metricName, mean, stdev, quantiles) |
| 17 | 19 | } |
| 20 | ||
| 21 | func TestCallbackGauge(t *testing.T) { | |
| 22 | value := 42.43 | |
| 23 | metricName := "foo" | |
| 24 | expvar.PublishCallbackGauge(metricName, func() float64 { return value }) | |
| 25 | if want, have := fmt.Sprint(value), stdexpvar.Get(metricName).String(); want != have { | |
| 26 | t.Errorf("want %q, have %q", want, have) | |
| 27 | } | |
| 28 | } | |
| 65 | 65 | } |
| 66 | 66 | } |
| 67 | 67 | |
| 68 | func TestPrometheusCallbackGauge(t *testing.T) { | |
| 69 | value := 123.456 | |
| 70 | cb := func() float64 { return value } | |
| 71 | prometheus.RegisterCallbackGauge("test", "prometheus_gauge", "bazbaz", "Help string.", cb) | |
| 72 | if want, have := strings.Join([]string{ | |
| 73 | `# HELP test_prometheus_gauge_bazbaz Help string.`, | |
| 74 | `# TYPE test_prometheus_gauge_bazbaz gauge`, | |
| 75 | `test_prometheus_gauge_bazbaz 123.456`, | |
| 76 | }, "\n"), teststat.ScrapePrometheus(t); !strings.Contains(have, want) { | |
| 77 | t.Errorf("metric stanza not found or incorrect\n%s", have) | |
| 78 | } | |
| 79 | } | |
| 80 | ||
| 68 | 81 | func TestPrometheusHistogram(t *testing.T) { |
| 69 | 82 | h := prometheus.NewHistogram("test", "prometheus_histogram", "foobar", "Qwerty asdf.", []string{}) |
| 70 | 83 |
| 77 | 77 | // It collects values every scrape interval from the callback. Values are |
| 78 | 78 | // buffered for the report interval or until the buffer exceeds a max packet |
| 79 | 79 | // size, whichever comes first. The report and scrape intervals may be the |
| 80 | // same. Fields are ignored. | |
| 80 | // same. The callback determines the value, and fields are ignored, so | |
| 81 | // NewCallbackGauge returns nothing. | |
| 81 | 82 | func NewCallbackGauge(w io.Writer, key string, reportInterval, scrapeInterval time.Duration, callback func() float64) { |
| 82 | 83 | go fwd(w, key, reportInterval, emitEvery(scrapeInterval, callback)) |
| 83 | 84 | } |
| 84 | 85 | |
| 85 | func emitEvery(d time.Duration, f func() float64) <-chan string { | |
| 86 | func emitEvery(d time.Duration, callback func() float64) <-chan string { | |
| 86 | 87 | c := make(chan string) |
| 87 | 88 | go func() { |
| 88 | for range time.Tick(d) { | |
| 89 | c <- fmt.Sprintf("%f|g", f()) | |
| 89 | for range tick(d) { | |
| 90 | c <- fmt.Sprintf("%f|g", callback()) | |
| 90 | 91 | } |
| 91 | 92 | }() |
| 92 | 93 | return c |
| 3 | 3 | |
| 4 | 4 | import ( |
| 5 | 5 | "bytes" |
| 6 | "fmt" | |
| 6 | 7 | "runtime" |
| 7 | 8 | "testing" |
| 8 | 9 | "time" |
| 37 | 38 | buf := &bytes.Buffer{} |
| 38 | 39 | g := NewGauge(buf, "test_statsd_gauge", time.Second) |
| 39 | 40 | |
| 40 | g.Add(1) // send command | |
| 41 | delta := 1.0 | |
| 42 | g.Add(delta) // send command | |
| 41 | 43 | runtime.Gosched() // yield to buffer write |
| 42 | 44 | ch <- time.Now() // signal flush |
| 43 | 45 | runtime.Gosched() // yield to flush |
| 44 | if want, have := "test_statsd_gauge:+1.000000|g\n", buf.String(); want != have { | |
| 46 | if want, have := fmt.Sprintf("test_statsd_gauge:+%f|g\n", delta), buf.String(); want != have { | |
| 45 | 47 | t.Errorf("want %q, have %q", want, have) |
| 46 | 48 | } |
| 47 | 49 | |
| 48 | 50 | buf.Reset() |
| 49 | 51 | |
| 50 | g.Add(-2) | |
| 52 | delta = -2.0 | |
| 53 | g.Add(delta) | |
| 51 | 54 | runtime.Gosched() |
| 52 | 55 | ch <- time.Now() |
| 53 | 56 | runtime.Gosched() |
| 54 | if want, have := "test_statsd_gauge:-2.000000|g\n", buf.String(); want != have { | |
| 57 | if want, have := fmt.Sprintf("test_statsd_gauge:%f|g\n", delta), buf.String(); want != have { | |
| 55 | 58 | t.Errorf("want %q, have %q", want, have) |
| 56 | 59 | } |
| 57 | 60 | |
| 58 | 61 | buf.Reset() |
| 59 | 62 | |
| 60 | g.Set(3) | |
| 63 | value := 3.0 | |
| 64 | g.Set(value) | |
| 61 | 65 | runtime.Gosched() |
| 62 | 66 | ch <- time.Now() |
| 63 | 67 | runtime.Gosched() |
| 64 | if want, have := "test_statsd_gauge:3.000000|g\n", buf.String(); want != have { | |
| 68 | if want, have := fmt.Sprintf("test_statsd_gauge:%f|g\n", value), buf.String(); want != have { | |
| 69 | t.Errorf("want %q, have %q", want, have) | |
| 70 | } | |
| 71 | } | |
| 72 | ||
| 73 | func TestCallbackGauge(t *testing.T) { | |
| 74 | ch := make(chan time.Time) | |
| 75 | tick = func(time.Duration) <-chan time.Time { return ch } | |
| 76 | defer func() { tick = time.Tick }() | |
| 77 | ||
| 78 | buf := &bytes.Buffer{} | |
| 79 | value := 55.55 | |
| 80 | cb := func() float64 { return value } | |
| 81 | NewCallbackGauge(buf, "test_statsd_callback_gauge", time.Second, time.Nanosecond, cb) | |
| 82 | ||
| 83 | ch <- time.Now() // signal emitter | |
| 84 | runtime.Gosched() // yield to emitter | |
| 85 | ch <- time.Now() // signal flush | |
| 86 | runtime.Gosched() // yield to flush | |
| 87 | ||
| 88 | if want, have := fmt.Sprintf("test_statsd_callback_gauge:%f|g\n", value), buf.String(); want != have { | |
| 65 | 89 | t.Errorf("want %q, have %q", want, have) |
| 66 | 90 | } |
| 67 | 91 | } |