Enum Tree

pub enum Tree {
    Event(Event),
    Span(Span),
}

A node in the log tree, consisting of either a Span or an Event.

The inner types can be extracted through a match statement. Alternatively, the event and span methods provide a more ergonomic way to access the inner types in unit tests when combined with the capture function.

Variants

Event(Event)

An Event leaf node.

Span(Span)

A Span inner node.

Implementations

impl Tree

pub fn event(&self) -> Result<&Event, ExpectedEventError>

Returns a reference to the inner Event if the tree is an event.

Errors

This function returns an error if the Tree contains the Span variant.

Examples

Inspecting a Tree returned from capture:

use tracing::{info, info_span};
use tracing_forest::tree::{Tree, Event};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let logs: Vec<Tree> = tracing_forest::capture()
        .build()
        .on(async {
            info!("some information");
        })
        .await;

    assert!(logs.len() == 1);

    let event: &Event = logs[0].event()?;
    assert!(event.message() == Some("some information"));

    Ok(())
}

pub fn span(&self) -> Result<&Span, ExpectedSpanError>

Returns a reference to the inner Span if the tree is a span.

Errors

This function returns an error if the Tree contains the Event variant.

Examples

Inspecting a Tree returned from capture:

use tracing::{info, info_span};
use tracing_forest::tree::{Tree, Span};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let logs: Vec<Tree> = tracing_forest::capture()
        .build()
        .on(async {
            info_span!("my_span").in_scope(|| {
                info!("inside the span");
            });
        })
        .await;

    assert!(logs.len() == 1);

    let my_span: &Span = logs[0].span()?;
    assert!(my_span.name() == "my_span");
    Ok(())
}

Trait Implementations

impl Clone for Tree

fn clone(&self) -> Tree

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Tree

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.