add test for static weight random remainder.

Signed-off-by: chaosi-zju <chaosi@zju.edu.cn>

pkg/scheduler/core/generic_scheduler_test.go

@@ -0,0 +1,93 @@
+/*
+Copyright 2023 The Karmada Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package core
+
+import (
+	"testing"
+
+	clusterv1alpha1 "github.com/karmada-io/karmada/pkg/apis/cluster/v1alpha1"
+	policyv1alpha1 "github.com/karmada-io/karmada/pkg/apis/policy/v1alpha1"
+	workv1alpha2 "github.com/karmada-io/karmada/pkg/apis/work/v1alpha2"
+	"github.com/karmada-io/karmada/test/helper"
+)
+
+// Test Case of even distribution of replicas, case 1
+// 1. create deployment (replicas=3), weight=1:1
+// 2. check two member cluster replicas, should be 2:1 or 1:2
+func Test_genericScheduler_AssignReplicas(t *testing.T) {
+	tests := []struct {
+		name      string
+		clusters  []*clusterv1alpha1.Cluster
+		placement *policyv1alpha1.Placement
+		object    *workv1alpha2.ResourceBindingSpec
+		wants     [][]workv1alpha2.TargetCluster
+		wantErr   bool
+	}{
+		{
+			name: "replica 3, static weighted 1:1",
+			clusters: []*clusterv1alpha1.Cluster{
+				helper.NewCluster(ClusterMember1),
+				helper.NewCluster(ClusterMember2),
+			},
+			object: &workv1alpha2.ResourceBindingSpec{
+				Replicas: 3,
+			},
+			placement: &policyv1alpha1.Placement{
+				ReplicaScheduling: &policyv1alpha1.ReplicaSchedulingStrategy{
+					ReplicaSchedulingType:     policyv1alpha1.ReplicaSchedulingTypeDivided,
+					ReplicaDivisionPreference: policyv1alpha1.ReplicaDivisionPreferenceWeighted,
+					WeightPreference: &policyv1alpha1.ClusterPreferences{
+						StaticWeightList: []policyv1alpha1.StaticClusterWeight{
+							{TargetCluster: policyv1alpha1.ClusterAffinity{ClusterNames: []string{ClusterMember1}}, Weight: 1},
+							{TargetCluster: policyv1alpha1.ClusterAffinity{ClusterNames: []string{ClusterMember2}}, Weight: 1},
+						},
+					},
+				},
+			},
+			wants: [][]workv1alpha2.TargetCluster{
+				{
+					{Name: ClusterMember1, Replicas: 1},
+					{Name: ClusterMember2, Replicas: 2},
+				},
+				{
+					{Name: ClusterMember1, Replicas: 2},
+					{Name: ClusterMember2, Replicas: 1},
+				},
+			},
+			wantErr: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			g := &genericScheduler{}
+			got, err := g.assignReplicas(tt.clusters, tt.placement, tt.object)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("AssignReplicas() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if tt.wantErr {
+				return
+			}
+			for _, want := range tt.wants {
+				if helper.IsScheduleResultEqual(got, want) {
+					return
+				}
+			}
+			t.Errorf("AssignReplicas() got = %v, wants %v", got, tt.wants)
+		})
+	}
+}