🌱 Add unit tests for roundrobin (#3202)

- Add tests for the round-robin token accessor

Signed-off-by: naveensrinivasan <[email protected]>

clients/githubrepo/roundtripper/tokens/round_robin_test.go

@@ -0,0 +1,48 @@
+// Copyright 2023 OpenSSF Scorecard 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 tokens
+
+import (
+	"testing"
+)
+
+//golint:paralleltest
+func TestNext(t *testing.T) {
+	tokens := []string{"token1", "token2", "token3", "token4", "token5"}
+	rr := makeRoundRobinAccessor(tokens)
+
+	tests := []struct {
+		name      string
+		releaseID *uint64 // nil if no token is released
+		want      string
+	}{
+		{"First call", nil, "token2"},
+		{"Second call", nil, "token3"},
+		{"Third call", nil, "token4"},
+		{"Fourth call", nil, "token5"},
+		{"After release", func() *uint64 { v := uint64(0); return &v }(), "token1"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if tt.releaseID != nil {
+				rr.Release(*tt.releaseID)
+			}
+			_, got := rr.Next()
+			if got != tt.want {
+				t.Errorf("Next() = %s, want %s", got, tt.want)
+			}
+		})
+	}
+}