## Contributing

### Developing

#### Development environment

Developing evcc requires [Go][1] 1.22 and [Node][2] 18. We recommend VSCode with the [Go](https://marketplace.visualstudio.com/items?itemName=golang.Go), [Prettier](https://marketplace.visualstudio.com/items?itemName=esbenp.prettier-vscode) and [Vetur](https://marketplace.visualstudio.com/items?itemName=octref.vetur) extensions.

We use linters (golangci-lint, Prettier) to keep a coherent source code formatting. It's recommended to use the format-on-save feature of your editor. You can manually reformat your code by running:

```sh
make lint
make lint-ui
```

#### Changing device templates

evcc supports a massive amount of different devices. To keep our documentation and website in sync with the latest software the core project (this repo) generates meta-data that's pushed to the `docs` and `evcc.io` repository. Make sure to update this meta-data every time you make changes to a templates.

```sh
make docs
```

If you miss one of the above steps Gitub Actions will likely trigger a **Porcelain** error.

### Building from source

Install prerequisites (once):

```sh
make install-ui
make install
```

Build and run:

```sh
make
./evcc
```

Open UI at http://127.0.0.1:7070

To run without creating the `evcc` binary use:

    go run ./...

#### Cross Compiling

To compile a version for an ARM device like a Raspberry Pi set GO command variables as needed, eg:

```sh
GOOS=linux GOARCH=arm GOARM=6 make
```

#### Publishing docker images

```sh
make docker DOCKER_IMAGE=my/docker DOCKER_TAG=0815
```

### Debugging in VS Code

#### evcc Core

To debug a local evcc build in VS Code, add the following entry to your `launch.json`.
You can adjust the referred configuration as needed to e.g. use your live configuration.

```json
{
    "name": "Launch evcc local build with demo config",
    "type": "go",
    "request": "launch",
    "mode": "auto",
    "program": "${workspaceFolder}",
    "args": ["-c", "${workspaceFolder}/cmd/demo.yaml"],
    "cwd": "${workspaceFolder}",
},
```

#### UI

For frontend development start the Vue toolchain in dev-mode. Open http://127.0.0.1:7071/ to get to the live reloading development server. It pulls its data from port 7070 (see above).

```sh
npm install
npm run dev
```

#### Integration testing

We use Playwright for end-to-end integration tests. They start a local evcc instance with different configuration yamls and prefilled databases. To run them, you have to do a local build first.

```sh
make ui build
npm run playwright
```

#### Simulating device state

Since we don't want to run tests against real devices or cloud services, we've build a simple simulator that lets you emulated meters, vehicles and loadpoints. The simulators web interface runs on http://localhost:7072.

```
npm run simulator
```

Run an evcc instance that uses simulator data. This configuration runs with a very high refresh interval to speed up testing.

```
make ui build
./evcc --config tests/simulator.evcc.yaml
```

### Adding or modifying translations

evcc already includes many translations for the UI. We're using [Weblate](https://hosted.weblate.org/projects/evcc/evcc/) to maintain translations. Feel free to add more languages or verify and edit existing translations. Weblate will automatically push all modifications to the evcc repository where they get reviewed and merged.

[![Languages](https://hosted.weblate.org/widgets/evcc/-/evcc/multi-auto.svg)](https://hosted.weblate.org/engage/evcc/)

[1]: https://go.dev
[2]: https://nodejs.org/