apply micro commit 2eb19c2e97d9316438bc66cd2cda896e8c99d026

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

selector/roundrobin/roundrobin.go

@@ -1,6 +1,8 @@
 package roundrobin
 
 import (
+	"math/rand"
+
 	"github.com/unistack-org/micro/v3/selector"
 )
 
@@ -17,7 +19,7 @@ func (r *roundrobin) Select(routes []string, opts ...selector.SelectOption) (sel
 		return nil, selector.ErrNoneAvailable
 	}
 
-	var i int
+	i := rand.Intn(len(routes))
 
 	return func() string {
 		route := routes[i%len(routes)]

selector/roundrobin/roundrobin_test.go

@@ -28,13 +28,22 @@ func TestRoundRobin(t *testing.T) {
 	assert.Nil(t, err, "Error should be nil")
 	assert.Equal(t, r2, r, "Expected route to be r2")
 
-	// Because r1 and r2 have been recently called, r3 should be chosen
-
-	next, err = sel.Select([]string{r1, r2, r3})
-	n1, n2, n3 := next(), next(), next()
+	routes := []string{r1, r2, r3}
+	next, err = sel.Select(routes)
 	assert.Nil(t, err, "Error should be nil")
-	assert.Equal(t, r1, n1, "Expected route to be r3")
-	assert.Equal(t, r2, n2, "Expected route to be r3")
-	assert.Equal(t, r3, n3, "Expected route to be r3")
+	n1, n2, n3, n4 := next(), next(), next(), next()
 
+	// start element is random but then it should loop through in order
+	start := -1
+	for i := 0; i < 3; i++ {
+		if n1 == routes[i] {
+			start = i
+			break
+		}
+	}
+	assert.NotEqual(t, start, -1)
+	assert.Equal(t, routes[start], n1, "Unexpected route")
+	assert.Equal(t, routes[(start+1)%3], n2, "Unexpected route")
+	assert.Equal(t, routes[(start+2)%3], n3, "Unexpected route")
+	assert.Equal(t, routes[(start+3)%3], n4, "Unexpected route")
 }