Crate playwright_rs_trace

Expand description

Programmatic parser for Playwright trace zip files (trace format v8, verified against traces recorded by the bundled Playwright 1.61 driver).

§When to reach for this crate

Pairs with the producer side, playwright-rs::Tracing (which writes .trace.zip files during a test run). This crate is the consumer side: a streaming, no-Playwright-server-required parser for those files. Typical users:

CI bots that comment on PRs with “test X failed at this Locator”
Dashboards that aggregate flaky-test root causes across runs
AI agent feedback loops that learn from past trace failures
Post-mortem analyzers run from a Rust binary or xtask

No runtime dependency on the main playwright-rs crate — pull in only this crate (typically as a [dev-dependencies] entry) when you want to read traces.

§Quick example

use playwright_rs_trace::open;

let mut reader = open("trace.zip")?;
println!(
    "trace v{} from {}",
    reader.context().version,
    reader.context().browser_name,
);

for action in reader.actions()? {
    let action = action?;
    if action.error.is_some() {
        eprintln!(
            "failed: {}.{} ({:?})",
            action.class, action.method, action.error,
        );
    }
}

The reader is a streaming iterator — events / actions are yielded lazily as the underlying zip stream is read, so a large trace doesn’t need to fit in memory before processing begins.

§Four streaming entry points on `TraceReader`

raw_events — every JSONL line as raw JSON. Forward-compat escape hatch for callers dispatching on event kinds we don’t model.
events — same lines parsed into a typed TraceEvent enum. Unknown / future kinds surface as TraceEvent::Unknown.
actions — before + optional input + zero-or-more log + after chunks reassembled into a logical Action. The common case; use this unless you specifically need the raw event stream.
network — NetworkEntrys from the trace.network HAR-shape stream (request / response pairs). Independent of the action stream — collect-and-sort if you need a merged chronological view.

§Forward compatibility

Every JSONL line is preserved losslessly via TraceReader::raw_events. The typed iterators (TraceReader::events, TraceReader::actions) deserialize what the parser models and route anything else to TraceEvent::Unknown so nothing is silently dropped.

See the crate README.md for the full slice-plan and roadmap.

Structs§

Action: A logical action — class.method call as recorded in the trace.
ActionError: Failure payload attached to an AfterEvent.
ActionStream: Streaming reassembly of Actions from a TraceEvent iterator. Use crate::TraceReader::actions to construct the typical case; public here so callers can wrap their own custom event source.
AfterEvent: Action-completion event.
BeforeEvent: Action-start event. Pairs with a matching AfterEvent sharing call_id.
ConsoleEvent: Browser console output captured during the trace.
ConsoleLocation
ContextOptions: Per-context metadata — appears once per trace as the first event in trace.trace.
FrameSnapshotEvent: Per-frame DOM snapshot. Includes the full HTML payload — these can be sizeable; callers iterating on snapshots for many frames should expect the per-event size to dominate the overall trace memory budget.
HeaderEntry
InputEvent: Optional input-coordinate / input-snapshot reference attached to an in-flight action.
LogEvent: Log line emitted during an in-flight action.
LogLine: One log line attached to an action via the log event.
NetworkEntry: One entry from trace.network — a HAR-like resource snapshot recording a single HTTP request/response pair (or a single redirect step in a chain).
Point: 2D coordinates for input events and click targets. Used in InputEvent::point and AfterEvent::point.
RawEvent: A single event from the trace, preserved as the underlying JSON object. Forward-compat escape hatch for callers who need to dispatch on event kinds the parser doesn’t model yet.
RequestPostData
RequestSnapshot
ResourceOverride: External resource reference used by a snapshot. Either a SHA-1 hash (resolved through the zip’s resources/ directory) or an internal reference identifier the trace viewer reassembles.
ResponseContent
ResponseSnapshot
ScreencastFrameEvent: Single screencast frame stored as a JPEG in resources/<sha1>.
SystemEvent: System events (dialog, download, page open/close). Mirrors the event chunk type in the trace.
TraceReader: Streaming reader over a Playwright trace zip.
Viewport

Enums§

TraceError
TraceEvent: Strongly-typed variants for the event kinds this version of the parser models. Unknown / unmodelled kinds surface as TraceEvent::Unknown to preserve the underlying JSON.

Functions§

open: Convenience wrapper for TraceReader::open over a file on disk.

Type Aliases§

Result