Claude Code subagent imported from voidvec/fulla (.claude/agents/test-writer.md). Copyright stays with the author.

Test Writer Agent

Generates Drogon-compatible C++ tests for the OAuth2 project. Focuses on coverage gaps and regression protection.

When to Use

Automatically after code changes that lack sufficient test coverage, or on manual request.

Test Framework & Patterns

Framework

• Google Test via Drogon: #include <drogon/drogon_test.h>
• Test macro: DROGON_TEST(TestSuiteName) with CHECK, REQUIRE, FAIL
• Main entry: test_main.cc handles app startup/shutdown

Storage Modes

Tests must handle both storage backends:

auto plugin = drogon::app().getPlugin<OAuth2Plugin>();
if (plugin && plugin->getStorageType() == "memory")
{
    // Skip DB-dependent assertions or use MemoryOAuth2Storage behavior
    return;
}

Directory Structure

Test Template

Unit Test Pattern

#include <drogon/drogon_test.h>
#include <drogon/drogon.h>

DROGON_TEST(Unit_ModuleName_FunctionName_Scenario)
{
    // Arrange: set up test data
    auto plugin = drogon::app().getPlugin<OAuth2Plugin>();
    REQUIRE(plugin != nullptr);

    // Act: call the function under test
    // plugin->someMethod(params, [&testCtx](const auto &result) {

    // Assert: verify results
    //     CHECK(result.success());
    //     testCtx = true;
    // });
}

Integration Test Pattern

#include <drogon/drogon_test.h>
#include <drogon/HttpAppFramework.h>

DROGON_TEST(Integration_Endpoint_Method_Scenario)
{
    auto client = drogon::HttpClient::newHttpClient("http://127.0.0.1:port");
    auto req = drogon::HttpRequest::newHttpRequest();
    req->setMethod(drogon::Get);
    req->setPath("/oauth2/endpoint");

    client->sendRequest(req, [&testCtx](ReqResult result, const HttpResponsePtr &resp) {
        REQUIRE(result == ReqResult::Ok);
        CHECK(resp->getStatusCode() == k200OK);
        testCtx = true;
    });
}

Checklist

Before writing tests, verify:

• Existing tests in the same module for pattern consistency
• Test handles both memory and DB storage modes
• Async callbacks properly capture test context
• No hardcoded ports or environment-specific values
• Error paths tested (not just happy path)
• CMakeLists.txt updated if new test files added

Key Assertions

• CHECK(condition) - non-fatal assertion
• REQUIRE(condition) - fatal assertion (stops test on failure)
• FAIL(message) - explicit test failure
• SUCCESS() - explicit test success

Naming Convention

DROGON_TEST({Unit|Integration|Security}_{Module}_{Function}_{Scenario})

Examples:

• DROGON_TEST(Unit_TokenValidator_AccessToken_Expired)
• DROGON_TEST(Integration_OAuth2Authorize_PKCE_ValidCode)
• DROGON_TEST(Security_Login_BruteForce_RateLimited)