src/dawn/node/test/V8TestEnvironment.h

// Copyright 2026 The Dawn & Tint Authors
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#ifndef SRC_DAWN_NODE_TEST_V8TESTENVIRONMENT_H_
#define SRC_DAWN_NODE_TEST_V8TESTENVIRONMENT_H_

#include <gtest/gtest.h>

#include <memory>
#include <optional>

#include <v8.h>

namespace dawn::node::test {

// The platform the test binary initialized V8 with. Registering a gtest global environment brings
// V8 up once for the whole binary, because InitializePlatform() and Initialize() are process-wide
// and cannot be undone and redone between tests.
//
// A test that drives V8's foreground task queue needs that exact platform - a second platform
// would have its own, permanently empty, queue - and V8 exposes no way to ask for it.
v8::Platform* V8Platform();

// A fixture with an isolate of its own. SetUp() creates and enters one, opens a handle scope that
// outlives the test body, and enters a fresh context; TearDown() undoes all of it in reverse. A
// derived fixture that owns something built on the isolate releases it before delegating here.
class V8IsolateTest : public ::testing::Test {
  protected:
    // Pass kExplicit to keep V8 from draining microtasks on its own, so that a test can pin down
    // when they run.
    explicit V8IsolateTest(v8::MicrotasksPolicy microtasks_policy)
        : microtasks_policy_(microtasks_policy) {}

    void SetUp() override;
    void TearDown() override;

    v8::Local<v8::Context> context() const { return isolate_->GetCurrentContext(); }

    v8::Isolate* isolate_ = nullptr;

  private:
    const v8::MicrotasksPolicy microtasks_policy_;
    std::unique_ptr<v8::ArrayBuffer::Allocator> allocator_;
    v8::Isolate::CreateParams create_params_;
    std::optional<v8::HandleScope> handle_scope_;
};

}  // namespace dawn::node::test

#endif  // SRC_DAWN_NODE_TEST_V8TESTENVIRONMENT_H_