Building an Automated Icon Generation Workflow

In modern mobile development, efficiency is key.Manually resizing and exporting dozens of icon assets for iOS and Android is tedious and error - prone.By automating this workflow, you can save time and ensure perfect consistency across every build.

Why Automate ?

- Consistency : Eliminate human error.Ensure every icon size is generated from the same source file every time.
- Speed: Generate hundreds of assets in seconds instead of hours.
- Version Control: Track a single source file(e.g., `icon.svg`) instead of committing hundreds of binary images to your repo.

The Workflow

A typical automated icon workflow involves three main steps:

1. Source Management: Keeping a high - resolution master file.
2. Generation Script: A tool to process the master file into platform - specific assets.
3. Integration: Hooking this process into your build system.

1. Source Management

Keep your master icon as a vector file(SVG) or a high - resolution PNG(1024x1024px).Store this in a dedicated `assets/source` directory.

2. Using Tools like Expo CLI

If you are using Expo, automation is built-in.

```json
// app.json
{
"expo": {
"icon": "./assets/icon.png",
"splash": {
"image": "./assets/splash.png"
}
}
}
```

With this configuration, Expo(specifically EAS Build or `npx expo prebuild`) automatically generates the native android and ios folders with all the correct icon densities.

3. CI/CD Integration

For teams using Continuous Integration (CI), you can ensure icons are fresh on every build.

Example GitHub Actions Step:

```yaml
- name: Install dependencies
run: npm install

- name: Generate Native Assets
run: npx expo prebuild--platform all--no - install
```

This command ensures that whatever is in your `app.json` is faithfully reproduced in the native projects before compilation.

Advanced: ImageMagick & Custom Scripts

For non-Expo projects or custom needs, you might use ImageMagick. A simple shell script can generate all sizes:

```bash
#!/bin/bash

Generate iOS Icons
convert icon.png - resize 20x20 ios / AppIcon.appiconset / Icon - 20.png
convert icon.png - resize 40x40 ios / AppIcon.appiconset / Icon - 40.png

...and so on
```

Maintaining Consistency

- Lock Source Files: Only the lead designer or designated developer should update the source `icon.png`.
- Review Changes: Treat icon updates like code changes. Review them in Pull Requests.
- Automated Validation: Use tools to verify that your `app.json` points to valid existing files before building.

Conclusion

Automating your icon generation workflow allows you to focus on building features rather than resizing images. Whether using Expo's built-in tools or custom scripts, the investment in setup pays off in long-term stability and speed.