pub struct Error {
pub profile: Option<Profile>,
pub metadata: Option<Metadata>,
pub path: Vec<String>,
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
implsFrom<String>
:use figment::Error; Error::from("whoops, something went wrong!".to_string());
-
Via a
Kind
, sinceError
implsFrom<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>
The path to the configuration key that errored, if known.
kind: Kind
The error kind.
Implementations
sourceimpl Error
impl Error
sourcepub fn missing(&self) -> bool
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());
sourcepub fn with_path(self, path: &str) -> Self
pub fn with_path(self, path: &str) -> Self
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");
sourcepub fn count(&self) -> usize
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(())
});
Trait Implementations
sourceimpl Error for Error
impl Error for Error
sourcefn custom<T: Display>(msg: T) -> Self
fn custom<T: Display>(msg: T) -> Self
sourcefn invalid_type(unexp: Unexpected<'_>, exp: &dyn Expected) -> Self
fn invalid_type(unexp: Unexpected<'_>, exp: &dyn Expected) -> Self
Deserialize
receives a type different from what it was
expecting. Read moresourcefn invalid_value(unexp: Unexpected<'_>, exp: &dyn Expected) -> Self
fn invalid_value(unexp: Unexpected<'_>, exp: &dyn Expected) -> Self
Deserialize
receives a value of the right type but that
is wrong for some other reason. Read moresourcefn invalid_length(len: usize, exp: &dyn Expected) -> Self
fn invalid_length(len: usize, exp: &dyn Expected) -> Self
sourcefn unknown_variant(variant: &str, expected: &'static [&'static str]) -> Self
fn unknown_variant(variant: &str, expected: &'static [&'static str]) -> Self
Deserialize
enum type received a variant with an
unrecognized name. Read moresourcefn unknown_field(field: &str, expected: &'static [&'static str]) -> Self
fn unknown_field(field: &str, expected: &'static [&'static str]) -> Self
Deserialize
struct type received a field with an
unrecognized name. Read moresourcefn missing_field(field: &'static str) -> Self
fn missing_field(field: &'static str) -> Self
Deserialize
struct type expected to receive a required
field with a particular name but that field was not present in the
input. Read moresourcefn duplicate_field(field: &'static str) -> Self
fn duplicate_field(field: &'static str) -> Self
Deserialize
struct type received more than one of the
same field. Read more