durations are now optionally spans for jitter

config/duration_test.go

@@ -0,0 +1,105 @@
+package config
+
+import (
+	"encoding/json"
+	"testing"
+	"time"
+)
+
+func TestDurationMarshal(t *testing.T) {
+	cases := map[string]struct {
+		in     string
+		want   Duration
+		wantJS string
+	}{
+		"empty string": {
+			wantJS: `"0s..0s"`,
+		},
+		"random in": {
+			in:     "abc",
+			want:   Duration{},
+			wantJS: `"0s..0s"`,
+		},
+		"1 dur": {
+			in: "1m",
+			want: Duration{
+				least: time.Minute,
+				most:  time.Minute,
+			},
+			wantJS: `"1m0s..1m0s"`,
+		},
+		"descending": {
+			in: "2m..1m",
+			want: Duration{
+				least: time.Minute,
+				most:  2 * time.Minute,
+			},
+			wantJS: `"1m0s..2m0s"`,
+		},
+		"happy span": {
+			in: "1m..2m",
+			want: Duration{
+				least: time.Minute,
+				most:  2 * time.Minute,
+			},
+			wantJS: `"1m0s..2m0s"`,
+		},
+		"multi unit descending": {
+			in: "1h1m..2m3ms",
+			want: Duration{
+				least: 2*time.Minute + 3*time.Millisecond,
+				most:  time.Hour + time.Minute,
+			},
+			wantJS: `"2m0.003s..1h1m0s"`,
+		},
+	}
+
+	for name, d := range cases {
+		c := d
+		t.Run(name, func(t *testing.T) {
+			var got Duration
+			err := json.Unmarshal([]byte(`"`+c.in+`"`), &got)
+			if got != c.want {
+				t.Fatalf("err %v: want %+v, got %+v", err, c.want, got)
+			}
+			js, _ := json.Marshal(got)
+			if string(js) != c.wantJS {
+				t.Fatalf("want marshalled %s, got %s", c.wantJS, js)
+			}
+			var got2 Duration
+			json.Unmarshal(js, &got2)
+			if got != got2 {
+				t.Fatalf("want unmarshal-marshal-unmarshal %+v, got %+v", got, got2)
+			}
+		})
+	}
+}
+
+func TestDurationGet(t *testing.T) {
+	t.Run("same", func(t *testing.T) {
+		d := Duration{least: time.Second, most: time.Second}
+		for i := 0; i < 50; i++ {
+			if got := d.Get(); got != time.Second {
+				t.Error(got)
+			}
+		}
+	})
+
+	t.Run("1ms span", func(t *testing.T) {
+		d := Duration{least: time.Second, most: time.Second + time.Millisecond}
+		for i := 0; i < 50; i++ {
+			if got := d.Get(); got != time.Second {
+				t.Error(got)
+			}
+		}
+	})
+
+	t.Run("5s span", func(t *testing.T) {
+		d := Duration{least: time.Second, most: 6 * time.Second}
+		for i := 0; i < 50; i++ {
+			if got := d.Get(); got > time.Second*6 || got < time.Second {
+				t.Error(got)
+			}
+		}
+	})
+}