🌱 Added unit tests for rpc (ossf#3203)

- Add a mockTokenAccessor and TokenOverRPC wrapper for testing
- Add tests for TokenOverRPC.Next and TokenOverRPC.Release

[clients/githubrepo/roundtripper/tokens/rpc_test.go]
- Add a mockTokenAccessor for testing
- Add a TokenOverRPC wrapper
- Add a Next method to TokenOverRPC
- Add a Release method to TokenOverRPC
- Add a test for TokenOverRPC.Next
- Add a test for TokenOverRPC.Release

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

clients/githubrepo/roundtripper/tokens/rpc_test.go

@@ -0,0 +1,77 @@
+// 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"
+
+// mockTokenAccessor implements TokenAccessor for testing.
+type mockTokenAccessor struct {
+	tokens  []string
+	counter uint64
+}
+
+// Next implements TokenAccessor.Next.
+func (m *mockTokenAccessor) Next() (uint64, string) {
+	if len(m.tokens) == 0 {
+		return 0, ""
+	}
+	token := m.tokens[0]
+	m.tokens = m.tokens[1:]
+	m.counter++
+	return m.counter, token
+}
+
+// Release implements TokenAccessor.Release.
+func (m *mockTokenAccessor) Release(id uint64) {
+	// No-op for mock.
+}
+
+// NewMockTokenAccessor creates a new mockTokenAccessor.
+func newMockTokenAccessor(tokens []string) *mockTokenAccessor {
+	return &mockTokenAccessor{
+		tokens: tokens,
+	}
+}
+
+func TestTokenOverRPC_Next(t *testing.T) {
+	mockClient := newMockTokenAccessor([]string{"token1", "token2", "token3"})
+	rpc := NewTokenOverRPC(mockClient)
+	token := &Token{}
+	x := struct{}{}
+	err := rpc.Next(x, token)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if token.Value != "token1" {
+		t.Fatalf("unexpected token: %s", token.Value)
+	}
+	err = rpc.Next(x, token)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if token.Value != "token2" {
+		t.Fatalf("unexpected token: %s", token.Value)
+	}
+}
+
+func TestTokenOverRPC_Release(t *testing.T) {
+	mockClient := newMockTokenAccessor([]string{"token1", "token2", "token3"})
+	rpc := NewTokenOverRPC(mockClient)
+
+	var reply struct{}
+	err := rpc.Release(2, &reply)
+	if err != nil {
+		t.Errorf("Expected no error, got %v", err)
+	}
+}