Describe the state
Use #Preview, @Previewable or PreviewProvider.
SwiftUI previews → snapshot tests
Previews, ready to test.
Prefire reads #Preview and generates snapshot tests plus an iOS Playbook. No second set of UI states.
One source
One preview. Two outputs.
The states already in your project become tests and a visual catalog.
01 — 02
Tests and Playbook.
One set of preview states becomes repeatable checks and a browsable interface catalog.
Snapshot testsiOS · tvOS · macOS
PlaybookiOS
Snapshot tests
Login / loadingpassed
Login / readypassed
Login / errorpassed
Three steps
Keep writing previews.
Prefire handles the path from source code to generated output.
Build the target
The plugin finds previews and generates Swift output.
Test or browse
Run snapshots or open Playbook to inspect the same states.
Install
Choose how Prefire runs.
Use the plugin in Xcode or SwiftPM. Use the CLI for explicit local and CI runs.
Xcode Build Tool Plugin
Add Prefire as a package dependency, then attach the test or Playbook plugin to the matching target.
Tests target → PrefireTestsPlugin App target → PrefirePlaybookPlugin
Swift Package plugins
Add Prefire once, then attach plugins to the targets that should receive generated output.
.package( url: "https://github.com/BarredEwe/Prefire.git", from: "5.8.1" ) .plugin(name: "PrefireTestsPlugin", package: "Prefire")
CLI
Install with Homebrew, then generate tests or Playbook models explicitly.
brew install BarredEwe/formulae/prefire prefire tests prefire playbook
Need custom paths, devices or templates?
Add .prefire.yml when the defaults no longer match your project. Project-specific control stays in the config.
test_configuration: target: PrefireExample simulator_device: "iPhone15,2" required_os: 16 playbook_configuration: preview_default_enabled: true
Open source
Your previews are already the fixture.
Let Prefire turn them into something the whole team can verify.