From c857b7ae0f1d5b75cffcd4f0cb97d86c28065d0f Mon Sep 17 00:00:00 2001
From: sighphyre <liquidwicked64@gmail.com>
Date: Mon, 3 Apr 2023 16:28:27 +0200
Subject: [PATCH] fix: patch random stickiness calculations for rollout
 strategies

---
 internal/strategies/flexible_rollout_test.go | 32 ++++++++++++++++++++
 internal/strategies/helpers.go               |  5 ++-
 internal/strategies/helpers_test.go          |  2 +-
 3 files changed, 37 insertions(+), 2 deletions(-)
 create mode 100644 internal/strategies/flexible_rollout_test.go

diff --git a/internal/strategies/flexible_rollout_test.go b/internal/strategies/flexible_rollout_test.go
new file mode 100644
index 0000000..566a96d
--- /dev/null
+++ b/internal/strategies/flexible_rollout_test.go
@@ -0,0 +1,32 @@
+package strategies
+
+import (
+	"testing"
+
+	"github.com/Unleash/unleash-client-go/v3/context"
+	"github.com/Unleash/unleash-client-go/v3/strategy"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestFlexibleRolloutStrategy_IsWellDistributed(t *testing.T) {
+	s := NewFlexibleRolloutStrategy()
+
+	enabledCount := 0
+	rounds := 200000
+
+	for i := 0; i < rounds; i++ {
+		params := map[string]interface{}{
+			strategy.ParamStickiness: "random",
+			strategy.ParamRollout:    50,
+			strategy.ParamGroupId:    "test51",
+		}
+		enabled := s.IsEnabled(params, &context.Context{})
+		if enabled {
+			enabledCount++
+		}
+	}
+
+	actualPercentage := round(100.0 * float64(enabledCount) / float64(rounds))
+
+	assert.InDelta(t, 50, actualPercentage, 1.0)
+}
diff --git a/internal/strategies/helpers.go b/internal/strategies/helpers.go
index 1f3ed5c..236281c 100644
--- a/internal/strategies/helpers.go
+++ b/internal/strategies/helpers.go
@@ -84,7 +84,10 @@ func (r *rng) float() float64 {
 }
 
 func (r *rng) string() string {
-	return strconv.Itoa(r.int())
+	r.Lock()
+	n := r.random.Intn(10000) + 1
+	r.Unlock()
+	return strconv.Itoa(n)
 }
 
 // newRng creates a new random number generator for numbers between 1-100
diff --git a/internal/strategies/helpers_test.go b/internal/strategies/helpers_test.go
index 652a6e6..da7e395 100644
--- a/internal/strategies/helpers_test.go
+++ b/internal/strategies/helpers_test.go
@@ -75,7 +75,7 @@ func TestNewRng(t *testing.T) {
 			assert.True(t, randomInt >= 0 && randomInt <= 100)
 
 			randomString := rng.string()
-			assert.True(t, len(randomString) <= 3)
+			assert.True(t, len(randomString) <= 5)
 
 			randomFloat := rng.float()
 			assert.True(t, randomFloat > 0.0 && randomFloat <= 100.0)