unreal-linter (Docker image)

Small Docker-based linter that performs:

• C/C++ formatting checks with clang-format (uses local .clang-format)
• C# formatting checks with dotnet format (requires compatible SDK/runtime)
• Unreal Engine asset file name checks using unreal-asset-name.csv rules

Currently .clang-format and .editorconfig must be present in the project root. (the files in the repo are examples)

This repository contains a multi-stage Dockerfile (Fedora-based) and helper scripts under scripts/.

Build the image (from the repo root):

docker build -t unreal-linter:latest .

Run the linter against a local Unreal project (mount project to /workspace):

Basic (defaults):

docker run --rm -v "$(pwd):/workspace" unreal-linter:latest

Including/excluding specific asset directories / source directories (recommended via env vars):

docker run --rm -v "$(pwd):/workspace" \
  -e INCLUDE_SOURCE_DIRS="Source" \
  -e EXCLUDE_SOURCE_DIRS="" \
  -e INCLUDE_UNREAL_ASSETS_DIRS="Content" \
  -e EXCLUDE_UNREAL_ASSETS_DIRS="Content/_DevImport,Content/__ExternalObjects__,Content/__ExternalActors__" \
  unreal-linter:latest

Output example (with some intentional failures):

Running checks against project at: /workspace

Checking C/C++ formatting...
----------------
Using INCLUDE_DIRS='Source' EXCLUDE_DIRS=''
C/C++ files formatted correctly.
--- [PASSED] ---

Checking C# formatting...
----------------
Using INCLUDE_DIRS='Source' EXCLUDE_DIRS=''
C# files formatted correctly.
--- [PASSED] ---

Checking Unreal asset names...
----------------
Using INCLUDE_DIRS='Content' EXCLUDE_DIRS='Content/_DevImport,Content/__ExternalObjects__,Content/__ExternalActors__'
Asset naming issues found:
 - Content/Levels/Example.uasset ("Example") does not match any naming rule
 - Content/Inputs/NULL_Character.uasset ("NULL_Character") does not match any naming rule
--- [FAILED] ---

CHECKS COMPLETE

--- RESULTS ---
One or more checks failed. Exiting with non-zero status.

Notes & behavior

• The asset name checker scans for asset extensions defined in scripts/check_asset_names.js (default includes .uasset, .umap, etc.). You can adjust that list in the script.
• C/C++ formatting: compares files with clang-format -style=file and reports differences; does not auto-fix unless you modify the script to run clang-format -i.
• C#: dotnet is installed in the image but the project's SDK version must be compatible with .NET SDK 7 installed in the container.

Limitations

• This tool checks filenames (.uasset/.umap etc.) — it does not parse asset internals inside Unreal packages.

Sources

• Unreal asset naming rules are based on Epic's guidelines, Unreal Directives and personal experience.