public final class Tracing

Tracing is a singleton to interact with registered Tracer implementations.

Support for actual tracing libraries is done by implementing wrappers following the interface. The actual Tracer implementations must be registered using registerTracer.

The Tracing singleton is also an entry point used to create the root span for any tests by invoking the beginSpan method. The returned Span object must be properly closed by invoking the close method or wrapping them in a try-resource block.

Summary

Public methods
@NonNull Tracer.Span

Returns a new Span as a managed resource in a try{} block. close is automatically called when the resource is released.
static @NonNull Tracing

Static getter for external access to the singleton.
void

Registers a new tracer.
void

Unregisters a tracer.

Public methods

beginSpan

@MustBeClosed
public @NonNull Tracer.Span beginSpan(@NonNull String name)

Returns a new Span as a managed resource in a try{} block. close is automatically called when the resource is released.

Parameters
@NonNull String name

A non-null name describing this span.

getInstance

public static @NonNull Tracing getInstance()

Static getter for external access to the singleton. Preferred method for internal Espresso is getting this singleton via dagger injection.

registerTracer

public void registerTracer(@NonNull Tracer tracer)

Registers a new tracer.

Once a tracer is registered, it starts being invoked for new root beginSpan calls. Existing in-flight spans do not invoke the new tracer.

Parameters
@NonNull Tracer tracer

A non-null Tracer object. A previously registered instance is ignored.

unregisterTracer

public void unregisterTracer(Tracer tracer)

Unregisters a tracer.

Once a tracer is unregistered, it will stop being invoked for any new root beginSpan calls made or any new beginChildSpan. However the tracer is still be called for any in-flight spans being closed.

Parameters
Tracer tracer

A Tracer object. A null reference or non-registered instance is ignored.