teasr-core

Orchestration and capture library for teasr. Handles config loading, server lifecycle, web/terminal/screen capture, and GIF conversion.

This crate is the engine behind the teasr CLI. Use it directly to embed teasr capture into your own Rust programs.

Usage

[dependencies]
teasr-core = "0.11"
tokio = { version = "1", features = ["full"] }

use teasr_core::{config, orchestrator};

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    // Discover teasr.toml walking up from cwd
    let cwd = std::env::current_dir()?;
    let config_path = config::discover_config(&cwd)
        .expect("no teasr.toml found");

    let config = config::load_config(&config_path)?;
    let results = orchestrator::run(&config).await?;

    for result in &results {
        println!("{}: {:?}", result.scene_name, result.files);
    }

    Ok(())
}

Config Loading

// Auto-discover: walks up from a directory to filesystem root
let path: Option<PathBuf> = config::discover_config(&start_dir);

// Load and resolve (applies defaults, validates scenes non-empty)
let config: ResolvedConfig = config::load_config(&path)?;

ResolvedConfig is the fully-defaulted version of the TOML config with all Option fields resolved.

Types

ResolvedConfig

pub struct ResolvedConfig {
    pub scenes: Vec<SceneConfig>,
    pub server: Option<ServerConfig>,
    pub viewport: ViewportConfig,     // default: 1280x720
    pub output: OutputConfig,         // default dir: ./teasr-output, formats: [Png]
    pub frame_duration_ms: u64,       // derived from fps (default: 24fps → 41ms)
    pub seconds: f64,                 // target output duration (default: 2.5s)
    pub scene_timeout: f64,           // per-scene wall-clock timeout (default: 60s)
}

SceneConfig

A tagged enum with variants Web, Screen, Terminal, and File. Mirrors the [[scenes]] TOML entries.

ServerConfig

pub struct ServerConfig {
    pub command: String,
    pub url: String,
    pub timeout: u64,   // ms, default: 10000
}

OutputConfig

pub struct OutputConfig {
    pub dir: String,                 // default: "./teasr-output"
    pub formats: Vec<OutputFormat>,  // default: [Png]
}

OutputFormat

pub enum OutputFormat {
    Png(PngConfig),
    Gif(GifConfig),     // quality: u8, fast: bool, repeat: Option<u16>
    Mp4(Mp4Config),     // fps: u32
}

CaptureResult

pub struct CaptureResult {
    pub scene_name: String,
    pub files: Vec<String>,  // absolute or relative paths of written files
}

Orchestrator

pub async fn orchestrator::run(config: &ResolvedConfig) -> Result<Vec<CaptureResult>>

Runs all scenes in declaration order:

1. Creates the output directory.
2. Starts the server (if server is set) and health-polls it until ready.
3. Iterates scenes, dispatching to the appropriate capture backend.
4. On drop, kills the server process group (Unix: SIGTERM then SIGKILL; Windows: TerminateProcess).

Capture Backends

Web (capture::web)

Uses chromiumoxide (Chrome DevTools Protocol) to navigate, execute actions (click, scroll, hover, wait), and take screenshots. Requires Chrome or Chromium on PATH or at a standard install location.

Terminal (capture::terminal)

Runs the command in a PTY via portable-pty, collects ANSI output, and delegates to teasr-term-render to produce a styled PNG.

Screen (capture::screen)

Captures a display or region using xcap. Supports display index selection and pixel-precise region cropping.

File (capture::file)

Renders a local file (HTML, SVG, PDF, etc.) in headless Chrome and captures a screenshot. No dev server required.

GIF Conversion (convert::gif)

pub fn frames_to_gif(frames: &[CapturedFrame], gif_path: &Path, config: &GifConfig) -> Result<()>

Assembles multiple captured frames into an animated GIF using gifski (pure Rust, no FFmpeg).

Server Lifecycle

ManagedServer is an RAII guard that starts a shell command in its own process group and tears it down on drop.

let server = ManagedServer::start(&server_config).await?;
// server is health-polled until config.url returns 2xx/3xx
// ...captures run...
// server killed when `server` is dropped

On Unix the entire process group receives SIGTERM, then SIGKILL 200 ms later, preventing orphaned child processes.

License

Apache-2.0