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
Raised when there is general error when deserializing a type. Read more
sourcefn invalid_type(unexp: Unexpected<'_>, exp: &dyn Expected) -> Self
fn invalid_type(unexp: Unexpected<'_>, exp: &dyn Expected) -> Self
Raised when a Deserialize
receives a type different from what it was
expecting. Read more
sourcefn invalid_value(unexp: Unexpected<'_>, exp: &dyn Expected) -> Self
fn invalid_value(unexp: Unexpected<'_>, exp: &dyn Expected) -> Self
Raised when a Deserialize
receives a value of the right type but that
is wrong for some other reason. Read more
sourcefn invalid_length(len: usize, exp: &dyn Expected) -> Self
fn invalid_length(len: usize, exp: &dyn Expected) -> Self
Raised when deserializing a sequence or map and the input data contains too many or too few elements. Read more
sourcefn unknown_variant(variant: &str, expected: &'static [&'static str]) -> Self
fn unknown_variant(variant: &str, expected: &'static [&'static str]) -> Self
Raised when a Deserialize
enum type received a variant with an
unrecognized name. Read more
sourcefn unknown_field(field: &str, expected: &'static [&'static str]) -> Self
fn unknown_field(field: &str, expected: &'static [&'static str]) -> Self
Raised when a Deserialize
struct type received a field with an
unrecognized name. Read more
sourcefn missing_field(field: &'static str) -> Self
fn missing_field(field: &'static str) -> Self
Raised when a Deserialize
struct type expected to receive a required
field with a particular name but that field was not present in the
input. Read more
sourcefn duplicate_field(field: &'static str) -> Self
fn duplicate_field(field: &'static str) -> Self
Raised when a Deserialize
struct type received more than one of the
same field. Read more
sourceimpl Error for Error
impl Error for Error
1.30.0 · sourcefn source(&self) -> Option<&(dyn Error + 'static)>
fn source(&self) -> Option<&(dyn Error + 'static)>
The lower-level source of this error, if any. Read more
1.0.0 · sourcefn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
sourceimpl IntoIterator for Error
impl IntoIterator for Error
sourceimpl PartialEq<Error> for Error
impl PartialEq<Error> for Error
impl StructuralPartialEq for Error
Auto Trait Implementations
impl !RefUnwindSafe for Error
impl Send for Error
impl Sync for Error
impl Unpin for Error
impl !UnwindSafe for Error
Blanket Implementations
sourceimpl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more