Struct rocket_db_pools::figment::error::Error

pub struct Error {
    pub profile: Option<Profile>,
    pub metadata: Option<Metadata>,
    pub path: Vec<String, Global>,
    pub kind: Kind,
    /* private fields */
}

Expand description

An error that occured while producing data or extracting a configuration.

Constructing Errors

An Error will generally be constructed indirectly via its implementations of serde’s de::Error and ser::Error, that is, as a result of serialization or deserialization errors. When implementing Provider, however, it may be necessary to construct an Error directly.

Broadly, there are two ways to construct an Error:

Via an error message, since Error impls From<String>:

use figment::Error;

Error::from("whoops, something went wrong!".to_string());

Via a Kind, since Error impls From<Kind>:

use figment::{error::{Error, Kind}, value::Value};

let value = Value::serialize(&100).unwrap();
if !value.as_str().is_some() {
    let kind = Kind::InvalidType(value.to_actual(), "string".into());
    let error = Error::from(kind);
}

As always, ? can be used to automatically convert into an Error using the available From implementations:

use std::fs::File;

fn try_read() -> Result<(), figment::Error> {
    let x = File::open("/tmp/foo.boo").map_err(|e| e.to_string())?;
    Ok(())
}

Display

By default, Error uses all of the available information about the error, including the Metadata, path, and profile to display a message that resembles the following, where $ is error. for some error: Error:

$kind: `$metadata.interpolate($path)` in $($metadata.sources())*

Concretely, such an error may look like:

invalid type: found sequence, expected u16: `staging.port` in TOML file Config.toml

Iterator

An Error may contain more than one error. To process all errors, iterate over an Error:

fn with_error(error: figment::Error) {
    for error in error {
        println!("error: {}", error);
    }
}

Fields§

§profile: Option<Profile>

The profile that was selected when the error occured, if any.

§metadata: Option<Metadata>

The metadata for the provider of the value that errored, if known.

§path: Vec<String, Global>

The path to the configuration key that errored, if known.

§kind: Kind

The error kind.

Implementations§

§

impl Error

pub fn missing(&self) -> bool

Returns true if the error’s kind is MissingField.

Example

use figment::error::{Error, Kind};

let error = Error::from(Kind::MissingField("path".into()));
assert!(error.missing());

pub fn with_path(self, path: &str) -> Error

Append the string path to the error’s path.

Example

use figment::Error;

let error = Error::from("an error message".to_string())
    .with_path("some_path");

pub fn count(&self) -> usize

Returns the number of errors represented by self.

Example

use figment::{Figment, providers::{Format, Toml}};

figment::Jail::expect_with(|jail| {
    jail.create_file("Base.toml", r#"
        cat = [1
    "#)?;

    jail.create_file("Release.toml", r#"
        cat = "
    "#)?;

    let figment = Figment::from(Toml::file("Base.toml"))
        .merge(Toml::file("Release.toml"));

    let error = figment.extract_inner::<String>("cat").unwrap_err();
    assert_eq!(error.count(), 2);

    Ok(())
});