Add tests for array difference function

ec/ecresource/organizationresource/list_difference.go

@@ -0,0 +1,43 @@
+// Licensed to Elasticsearch B.V. under one or more contributor
+// license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright
+// ownership. Elasticsearch B.V. licenses this file to you 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 organizationresource
+
+// Returns all the elements from array a that are not in array b
+func difference[T interface{}](a, b []*T, getKey func(T) string) []*T {
+	var diff []*T
+	m := make(map[string]T)
+	for _, item := range b {
+		if item == nil {
+			continue
+		}
+		key := getKey(*item)
+		m[key] = *item
+	}
+
+	for _, item := range a {
+		if item == nil {
+			continue
+		}
+		key := getKey(*item)
+		if _, ok := m[key]; !ok {
+			diff = append(diff, item)
+		}
+	}
+
+	return diff
+}

ec/ecresource/organizationresource/list_difference_test.go

@@ -0,0 +1,88 @@
+// Licensed to Elasticsearch B.V. under one or more contributor
+// license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright
+// ownership. Elasticsearch B.V. licenses this file to you 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 organizationresource
+
+import (
+	"github.com/elastic/cloud-sdk-go/pkg/util/ec"
+	"reflect"
+	"testing"
+)
+
+func Test_difference(t *testing.T) {
+	type args struct {
+		a []*string
+		b []*string
+	}
+	type testCase struct {
+		name string
+		args args
+		want []*string
+	}
+	tests := []testCase{
+		{
+			name: "returns elements that are only in a",
+			args: args{
+				a: []*string{ec.String("a"), ec.String("b")},
+				b: []*string{ec.String("b"), ec.String("c")},
+			},
+			want: []*string{ec.String("a")},
+		},
+		{
+			name: "both lists empty, returns empty list",
+			args: args{
+				a: nil,
+				b: nil,
+			},
+			want: nil,
+		},
+		{
+			name: "if b empty, returns a",
+			args: args{
+				a: []*string{ec.String("a")},
+				b: nil,
+			},
+			want: []*string{ec.String("a")},
+		},
+		{
+			name: "if b has no elements in a, return a",
+			args: args{
+				a: []*string{ec.String("a")},
+				b: []*string{ec.String("b")},
+			},
+			want: []*string{ec.String("a")},
+		},
+		{
+			name: "if b has all elements of a, return empty list",
+			args: args{
+				a: []*string{ec.String("a")},
+				b: []*string{ec.String("a"), ec.String("b")},
+			},
+			want: nil,
+		},
+	}
+	for _, tt := range tests {
+		getKey := func(a string) string {
+			return a
+		}
+		t.Run(tt.name, func(t *testing.T) {
+			if got := difference(tt.args.a, tt.args.b, getKey); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("difference() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

ec/ecresource/organizationresource/update.go

@@ -266,27 +266,3 @@ func diffProjectRoleAssignments(old, new models.ProjectRoleAssignments) (*models
 	}
 	return &add, &remove
 }
-
-func difference[T interface{}](a, b []*T, getKey func(T) string) []*T {
-	var diff []*T
-	m := make(map[string]T)
-	for _, item := range b {
-		if item == nil {
-			continue
-		}
-		key := getKey(*item)
-		m[key] = *item
-	}
-
-	for _, item := range a {
-		if item == nil {
-			continue
-		}
-		key := getKey(*item)
-		if _, ok := m[key]; !ok {
-			diff = append(diff, item)
-		}
-	}
-
-	return diff
-}