# Extract a Shared Helper from Duplicated Code in Unreal Engine with Atlas in 2026

> Atlas enables Unreal Engine developers to find and refactor duplicated C++ logic into shared helpers, ensuring consistency and testability across their projects.

Atlas helps Unreal Engine developers in 2026 extract shared helpers from duplicated C++ code by semantically searching for near-identical logic, creating new modules via `Unreal Build Tool (Build.cs)`, and replacing copies with calls, all while ensuring code quality with `clang-format` and `Unreal Automation Framework`. This process ensures that even complex refactoring tasks in large Unreal Engine projects are manageable and verifiable.

## Key takeaways

- Atlas uses semantic search to find duplicated Unreal Engine C++ logic, even with variable name differences.
- New Unreal Engine modules and `Build.cs` dependencies are automatically managed by Atlas for proper integration.
- Refactoring changes are applied as independently reviewable `git` patches in Unreal Engine projects.
- `Unreal Automation Framework` tests are run via `bash` after each change to validate refactored Unreal Engine code.
- Atlas ensures Unreal Engine code adheres to the Epic style guide by applying `.clang-format`.
- Atlas provides full diff approval and `git` integration for safe Unreal Engine refactoring.

## How to find duplicated C++ code in Unreal Engine projects?

Atlas helps Unreal Engine developers in 2026 identify duplicated C++ logic across multiple files by using semantic search, which goes beyond simple text matching to find near-identical behaviors that `grep` would miss, even with different variable names. This capability is crucial for maintaining large codebases.

Finding duplicated code in Unreal Engine projects often involves more than just searching for identical text strings, as variable names or minor structural differences can obscure true semantic duplication. Atlas addresses this challenge by leveraging `codebase_search` with hybrid semantic and keyword retrieval, fused by reciprocal rank fusion. It indexes your Unreal Engine C++ codebase by AST declarations using tree-sitter, allowing it to understand the structure and meaning of your `UCLASS`, `UPROPERTY`, and `UFUNCTION` macros. This means Atlas can identify near-duplicate implementations of a specific behavior, even if the exact lines of code or variable names differ across `Source/` module folders. For instance, if the same complex calculation is copy-pasted into three different `Actor` classes, Atlas can surface all instances, enabling a targeted refactoring effort that traditional `grep` commands would likely miss due to minor variations.

## How to create a new shared helper module in Unreal Engine with Atlas?

Creating a new shared helper module in Unreal Engine with Atlas involves using the `write` tool to generate the C++ files and updating the `Build.cs` file to declare the new module, a critical step that many C++ agents miss, ensuring proper project structure for 2026. This ensures the module is correctly integrated.

Once duplicated logic is identified, the next step is to consolidate it into a new, shared helper. Atlas facilitates this by using its `write` tool to create new C++ header and source files for your helper module. For example, you might instruct Atlas to create `Source/SharedHelpers/Public/MyMathHelper.h` and `Source/SharedHelpers/Private/MyMathHelper.cpp`. Crucially, Atlas understands the Unreal Engine build system. Before adding the include for your new helper, Atlas will ask to add a module dependency in the relevant `Build.cs` file, such as `MyProject.Build.cs` or `MyModule.Build.cs`. This ensures that `Unreal Build Tool (Build.cs)` correctly compiles and links your new module, preventing common compilation errors. Atlas can also draft `UCLASS` or `UFUNCTION` macros within these new files, adhering to Unreal Engine's reflection system, making the helper accessible and discoverable within the engine.

## How to replace duplicated code with a shared helper call in Unreal Engine?

Replacing duplicated code with a call to a new shared helper in Unreal Engine is managed by Atlas's `apply_patch` tool, which generates one reviewable patch per file, allowing developers to approve each change independently and ensuring a controlled refactoring process in 2026. This granular approach enhances safety.

After the shared helper module is created, Atlas uses `apply_patch` to replace each instance of the duplicated logic with a call to the new helper function or class. This process is designed for safety and reviewability. Atlas computes a unified diff for every file edit and surfaces it for approval before writing, ensuring you have full control over every change. Each replacement is handled as an independent patch, meaning if you have five files with duplicated code, Atlas will propose five separate patches. This allows you to review and approve each swap individually, making it easy to revert a specific change if needed without affecting others. Atlas also reads `git` branches, status, and diffs, and can stage and create commits on your behalf, integrating direct into your existing Unreal Engine development workflow and version control practices.

## How to test and verify refactored Unreal Engine code with Atlas?

After each replacement of duplicated code with a shared helper call, Atlas recommends running the full test suite using the `Unreal Automation Framework` via the `bash` tool, ensuring that the refactoring maintains 100% functionality and prevents regressions in 2026. This iterative testing is vital.

Maintaining code integrity during refactoring is paramount, especially in complex Unreal Engine projects. Atlas integrates directly with your existing testing infrastructure. After each `apply_patch` operation that replaces duplicated code with a shared helper call, Atlas prompts you to run your test suite. You can execute these tests using the `bash` tool, specifically by invoking `UnrealEditor-Cmd.exe -run=AutomationTest -test=YourModuleName.YourTestName` or similar commands to run tests managed by the `Unreal Automation Framework`. This immediate feedback loop ensures that each change is validated, catching any regressions early. Furthermore, Atlas can write new Automation Spec tests if needed, and run them through `UnrealEditor-Cmd` behind a permission prompt. Finally, after all duplicates are replaced and tests pass, Atlas can help you `grep` for any surviving copies of the original duplicated logic, providing a final verification step and ensuring a clean refactor. Atlas also applies the engine `.clang-format` to ensure the code matches the Epic style guide.

## Steps

1. Run Atlas in your Unreal Engine project directory containing a `.uproject` file and `Source/` module folders.
2. Ask Atlas to `codebase_search` for the behavior of the duplicated logic, for example: `atlas codebase_search "calculate player damage based on weapon type"`.
3. Use `atlas read` to examine each identified file and confirm the copies are genuinely equivalent and suitable for extraction.
4. Instruct Atlas to `write` the new shared helper C++ files (e.g., `Source/MySharedModule/Public/DamageCalculator.h`) and approve the `Build.cs` dependency update for `Unreal Build Tool (Build.cs)`.
5. For each duplicated instance, use `atlas apply_patch` to replace the logic with a call to the new helper, reviewing the unified diff for each file.
6. After each `apply_patch`, run your Unreal Engine tests using `atlas bash "UnrealEditor-Cmd.exe -run=AutomationTest -test=MyProject.DamageTests"` to verify functionality with `Unreal Automation Framework`.
7. Approve the diff for `clang-format` application to ensure the new code adheres to the Epic style guide.
8. Perform a final check by using `atlas grep "old_duplicated_logic_pattern"` to ensure no copies remain.

## FAQ

### How does Atlas find duplicated C++ code in Unreal Engine projects?

Atlas uses `codebase_search` with hybrid semantic and keyword retrieval, indexing Unreal Engine C++ code by AST declarations using tree-sitter. This allows it to identify near-duplicate logic across `UCLASS` macros and `Source/` folders, even when variable names or minor structures differ, which traditional `grep` tools would miss.

### Can Atlas update my Unreal Engine Build.cs files for new modules?

Yes, Atlas is specifically designed to understand Unreal Engine's build system. When creating a new shared helper module, Atlas will ask to add the necessary module dependency in the relevant `Build.cs` file, ensuring `Unreal Build Tool (Build.cs)` correctly compiles and links your new code without manual intervention.

### How does Atlas ensure code style with Unreal Engine's guidelines?

Atlas integrates with `clang-format`, the standard formatter for Unreal Engine. After making code changes, Atlas can apply the engine's `.clang-format` configuration, ensuring that all new or modified code adheres to the Epic style guide, maintaining consistency across your project.

### What Unreal Engine testing tools does Atlas integrate with?

Atlas integrates directly with the `Unreal Automation Framework`. You can use the `bash` tool within Atlas to run `UnrealEditor-Cmd.exe` commands, executing your existing automation tests to verify that refactoring changes have not introduced any regressions.

### Is it safe to refactor Unreal Engine code with Atlas?

Yes, Atlas prioritizes safety. Every Atlas tool call is permission-gated, and it drafts a plan in a read-only agent before execution. It computes a unified diff for every file edit, surfacing it for your approval before writing. Each replacement is applied as an independent, reviewable patch, and Atlas integrates with `git` for easy rollback.

### Does Atlas support Unreal Engine's reflection system macros like UCLASS?

Absolutely. Atlas builds its code index using AST declarations, which means it understands and can process Unreal Engine's `UCLASS`, `UPROPERTY`, and `UFUNCTION` macros. This allows Atlas to generate and modify C++ code that correctly integrates with the engine's reflection system.

### How does Atlas handle large Unreal Engine codebases?

Atlas is built for scale. It indexes code efficiently using tree-sitter and can build its code index with local Ollama embeddings, keeping code off third-party servers. It also fans out work to subagents that can run in parallel background sessions, making it effective for large Unreal Engine projects with many `Source/` modules.

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Canonical HTML: https://runatlas.sh/resources/stacks/extract-a-shared-helper-from-duplicated-code-in-unreal
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Licence: Atlas is proprietary with a free core. It is not open source and there is no public source repository.