Development

This guide covers setting up a development environment, building from source, and contributing to File Mover Express.

Prerequisites

Tool	Minimum Version	Notes
Go	1.25	CLI daemon and the Wails desktop app
Node.js	22	GUI (Angular) and workspace tooling
Git	Any	Source control
Task	3	Build runner — every build/test/lint target is a Task
Wails CLI (`wails3`)	v3 (alpha)	Builds the desktop app and generates frontend bindings
golangci-lint	Latest	Go linter

The build is driven by Task (Taskfile.yml at the repo root plus a Taskfile.yml in each src/* package). The npm run * scripts are thin wrappers that call Task, so you can use either task <name> or npm run <name>.

Install the Wails v3 CLI with:

go install github.com/wailsapp/wails/v3/cmd/wails3@latest

macOS

brew install go node git go-task golangci-lint

Linux (Ubuntu/Debian)

sudo apt update
sudo apt install -y nodejs npm git

Install Go from go.dev/dl (the golang-go apt package is often behind), Task by following the Task install guide, and golangci-lint by following the official guide — the apt versions are frequently outdated. Building the desktop app on Linux also requires the Wails system dependencies (GTK/WebKit); see the Wails Linux prerequisites.

Windows

winget install GoLang.Go OpenJS.NodeJS Git.Git Task.Task

Install golangci-lint by following the official guide.

Architecture

filemoverexpress/
├── src/
│   ├── cli/                    # Go CLI daemon and backend services
│   ├── gui/                    # Angular GUI application (Wails frontend)
│   ├── wails/                  # Wails 3 desktop app (Go); embeds the GUI and the daemon
│   ├── protobuf/               # Protocol buffer definitions (buf)
│   └── windows-daemon-launcher/ # Windows daemon launcher helper
├── Taskfile.yml                # Root build orchestration (Task)
├── docs/                       # Documentation
├── CONTRIBUTING.md             # Contribution guidelines
├── SECURITY.md                 # Security policy
└── README.md                   # Project overview

The desktop application is built with Wails 3: src/wails/ is a Go app that embeds the Angular GUI from src/gui/ as its frontend and compiles the transfer daemon into the same binary. The standalone filemoverexpress CLI in src/cli/ is still built and used for scripting and headless operation.

Building from Source

Quick build (recommended)

task build runs the build in the correct order — CLI, GUI, and the Wails desktop app.

git clone https://github.com/awslabs/filemoverexpress.git
cd filemoverexpress
npm install
task generate           # generate protobuf + Wails bindings (first build only, or after proto/Go changes)
task build

Build outputs land in dist/ (CLI binaries) and src/wails/build/bin/ (the desktop app). The npm run * scripts (e.g. npm run build) are thin wrappers around these tasks if you prefer npm.

Tip: Task caches by input checksums, so re-running task build only rebuilds what changed. On a corporate/VPN network where proxy.golang.org is blocked, prefix Go builds with GOPROXY=direct (see Troubleshooting below).

Individual build steps

If you need to run steps individually:

# Generate all code (protobuf + Wails bindings)
task generate

# Generate protobuf code only (Go + TypeScript)
task proto:generate

# Build the CLI only (auto-detects your OS and architecture)
task cli:build

# Build the GUI only
task gui:build

# Build the Wails desktop app
task wails:build

Running tests

task test                   # Run all tests (CLI, Wails, GUI)
task cli:test               # Go CLI unit tests
task test:wails             # Wails (Go) tests
task gui:test               # GUI unit tests (Vitest, via ng test)

The GUI test suite runs on Vitest (it replaced Karma). task gui:test invokes ng test --watch=false --coverage.

Linting

task lint                   # Lint all code (CLI + GUI)
task cli:lint               # golangci-lint on Go code
task gui:lint               # ESLint on TypeScript/Angular code

Cleaning build artifacts

task clean                  # Remove build artifacts and generated code

Available Commands

Task is the primary interface; most targets have a matching npm run wrapper.

Task	npm wrapper	Description
`task build`	`npm run build`	Build CLI, GUI, and the Wails desktop app
`task generate`	—	Generate all code (protobuf + Wails bindings)
`task proto:generate`	`npm run build:proto`	Generate protobuf code only (Go + TypeScript)
`task cli:build`	`npm run build:cli`	Build CLI for current platform
`task gui:build`	`npm run build:gui`	Build GUI production bundle
`task wails:build`	`npm run build:wails`	Build the Wails desktop app
`task test`	`npm run test`	Run all tests
`task cli:test`	`npm run test:cli`	Run CLI unit and integration tests
`task test:wails`	`npm run test:wails`*	Run Wails (Go) tests
`task gui:test`	`npm run test:gui`	Run GUI unit tests via Vitest
`task lint`	`npm run lint`	Lint all code
`task dev`	—	Run the desktop app in hot-reload dev mode (`wails3 dev`)
`task clean`	—	Remove all build artifacts and generated code

_{* npm run test:wails currently maps to a non-existent task wails:test in package.json;
use task test:wails until that wrapper is fixed.}

Run task --list to see every available target.

Environment Variables

Variable	Description	Default
`BUILD_VERSION`	Version stamped into the built binaries	`0.0.0-local-dev`
`GOPROXY`	Set to `direct` if `proxy.golang.org` is blocked on your network	Go default

Desktop Development

To run the full desktop app with hot reload (frontend + Go backend):

task dev

This runs wails3 dev, which rebuilds and reloads the app as you edit the Go or Angular code.

GUI-only in a browser

If you're working on the Angular GUI and want to iterate in a browser instead:

npm run --prefix src/gui start

This runs ng serve and serves the GUI at http://localhost:4200. You'll need the CLI daemon running separately (filemoverexpress daemon) for the GUI to connect to.

Note: When serving in a browser, you may need to add http://localhost:4200 to the allowed_origins list in your configuration file for CORS to work during development. The packaged Wails app uses its own webview origin and does not need this. See Configuration for details.

Development Workflow

Fork the repository
Create a feature branch: feat/my-feature or fix/my-fix
Make changes and ensure all tests pass
Follow the guidelines in CONTRIBUTING.md
Submit a pull request with a clear description of changes

Troubleshooting

task generate / task proto:generate fails with "no such host" or DNS error On corporate or VPN networks, proxy.golang.org may be blocked:

export GOPROXY=direct
task generate          # or: task proto:generate for protobuf only

protoc-gen-go or wails3 not found The proto step installs the protobuf plugins automatically. If it still fails, ensure go is on your PATH and your Go version is 1.25 or higher (go version), and that $(go env GOPATH)/bin is on your PATH so the generated-code plugins and the wails3 CLI are found.

Go version too old (Linux) The golang-go apt package is often behind. Install Go directly from go.dev/dl instead.

Permission denied on Linux/macOS binary

chmod +x ./dist/filemoverexpress-*

For more help, see the Troubleshooting guide or open an issue on GitHub.

Prerequisites​

macOS​

Linux (Ubuntu/Debian)​

Windows​

Architecture​

Building from Source​

Quick build (recommended)​

Individual build steps​

Running tests​

Linting​

Cleaning build artifacts​

Available Commands​

Environment Variables​

Desktop Development​

GUI-only in a browser​

Development Workflow​

Troubleshooting​