Struct juniper::executor::FieldError

pub struct FieldError<S = DefaultScalarValue> { /* private fields */ }

Error type for errors that occur during field resolution

Field errors are represented by a human-readable error message and an optional Value structure containing additional information.

They can be converted to from any type that implements std::fmt::Display, which makes error chaining with the ? operator a breeze:

fn get_string(data: Vec<u8>) -> Result<String, FieldError>
{
    let s = String::from_utf8(data)?;
    Ok(s)
}

Implementations

impl<S> FieldError<S>

pub fn new<T: Display>(e: T, extensions: Value<S>) -> FieldError<S>

Construct a new error with additional data

You can use the graphql_value! macro to construct an error:

use juniper::FieldError;
use juniper::graphql_value;

FieldError::new(
    "Could not open connection to the database",
    graphql_value!({ "internal_error": "Connection refused" })
);

The extensions parameter will be added to the "extensions" field of the error object in the JSON response:

{
  "errors": [
    "message": "Could not open connection to the database",
    "locations": [{"line": 2, "column": 4}],
    "extensions": {
      "internal_error": "Connection refused"
    }
  ]
}

If the argument is Value::null(), no extra data will be included.

pub fn map_scalar_value<Into>(self) -> FieldError<Into>where
    S: ScalarValue,
    Into: ScalarValue,

Maps the ScalarValue type of this FieldError into the specified one.

Trait Implementations

impl<S: Debug> Debug for FieldError<S>

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

Formats the value using the given formatter.

impl<T: Display, S> From<T> for FieldError<S>where
    S: ScalarValue,

fn from(e: T) -> FieldError<S>

Converts to this type from the input type.

impl<S: PartialEq> PartialEq<FieldError<S>> for FieldError<S>

fn eq(&self, other: &FieldError<S>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<S1: ScalarValue, S2: ScalarValue> IntoFieldError<S2> for FieldError<S1>

impl<S> StructuralPartialEq for FieldError<S>