impl(oauth2): make MapCredentials() unit testable (#10426)

Add a variant of `rest_internal::MapCredentials()` that can be unit tested. Use this to test all interesting code paths in the function.
googleapis · Dec 13, 2022 · a65f43f · a65f43f
1 parent 4c59584
commit a65f43f
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Showing 3 changed files with 326 additions and 42 deletions.
diff --git a/google/cloud/internal/unified_rest_credentials.cc b/google/cloud/internal/unified_rest_credentials.cc
@@ -67,6 +67,14 @@ CreateServiceAccountCredentialsFromJsonContents(
 
 std::shared_ptr<oauth2_internal::Credentials> MapCredentials(
     std::shared_ptr<google::cloud::Credentials> const& credentials) {
+  return MapCredentials(std::move(credentials), [](Options const& options) {
+    return MakeDefaultRestClient("", options);
+  });
+}
+
+std::shared_ptr<oauth2_internal::Credentials> MapCredentials(
+    std::shared_ptr<google::cloud::Credentials> const& credentials,
+    oauth2_internal::HttpClientFactory client_factory) {
   class Visitor : public CredentialsVisitor {
    public:
     explicit Visitor(oauth2_internal::HttpClientFactory client_factory)
@@ -126,9 +134,7 @@ std::shared_ptr<oauth2_internal::Credentials> MapCredentials(
     oauth2_internal::HttpClientFactory client_factory_;
   };
 
-  Visitor visitor([](Options options) {
-    return MakeDefaultRestClient(std::string{}, std::move(options));
-  });
+  Visitor visitor(std::move(client_factory));
   CredentialsVisitor::dispatch(*credentials, visitor);
   return std::move(visitor.result);
 }

diff --git a/google/cloud/internal/unified_rest_credentials.h b/google/cloud/internal/unified_rest_credentials.h
@@ -17,6 +17,7 @@
 
 #include "google/cloud/credentials.h"
 #include "google/cloud/internal/oauth2_credentials.h"
+#include "google/cloud/internal/oauth2_http_client_factory.h"
 #include "google/cloud/version.h"
 #include <memory>
 
@@ -32,6 +33,15 @@ GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_BEGIN
 std::shared_ptr<oauth2_internal::Credentials> MapCredentials(
     std::shared_ptr<google::cloud::Credentials> const& credentials);
 
+/**
+ * @copydoc MapCredentials(std::shared_ptr<google::cloud::Credentials> const&)
+ *
+ * This is used in tests, where the HTTP client needs to be mocked.
+ */
+std::shared_ptr<oauth2_internal::Credentials> MapCredentials(
+    std::shared_ptr<google::cloud::Credentials> const& credentials,
+    oauth2_internal::HttpClientFactory client_factory);
+
 GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_END
 }  // namespace rest_internal
 }  // namespace cloud