Documentation
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Overview ¶
Package errors implements custom error interfaces for cosmos-sdk.
Error declarations should be generic and cover broad range of cases. Each returned error instance can wrap a generic error declaration to provide more details.
This package provides a broad range of errors declared that fits all common cases. If an error is very specific for an extension it can be registered outside of the errors package. If it will be needed my many extensions, please consider registering it in the errors package. To create a new error instance use Register function. You must provide a unique, non zero error code and a short description, for example:
var ErrZeroDivision = errors.Register(9241, "zero division")
When returning an error, you can attach to it an additional context information by using Wrap function, for example:
func safeDiv(val, div int) (int, err) {
if div == 0 {
return 0, errors.Wrapf(ErrZeroDivision, "cannot divide %d", val)
}
return val / div, nil
}
The first time an error instance is wrapped a stacktrace is attached as well. Stacktrace information can be printed using %+v and %v formats.
%s is just the error message %+v is the full stack trace %v appends a compressed [filename:line] where the error was created
Index ¶
- Constants
- Variables
- func ABCIError(codespace string, code uint32, log string) error
- func ABCIInfo(err error, debug bool) (codespace string, code uint32, log string)
- func AssertNil(err error)
- func IsOf(received error, targets ...error) bool
- func Recover(err *error)
- func Redact(err error) error
- func WithType(err error, obj interface{}) error
- func Wrap(err error, description string) error
- func Wrapf(err error, format string, args ...interface{}) error
- type Error
Examples ¶
Constants ¶
const ( // SuccessABCICode declares an ABCI response use 0 to signal that the // processing was successful and no error is returned. SuccessABCICode uint32 = 0 )
const UndefinedCodespace = "undefined"
UndefinedCodespace when we explicitly declare no codespace
Variables ¶
var ( // ErrPanic is only set when we recover from a panic, so we know to // redact potentially sensitive system info ErrPanic = Register(UndefinedCodespace, 111222, "panic") )
Functions ¶
func ABCIError ¶
ABCIError will resolve an error code/log from an abci result into an error message. If the code is registered, it will map it back to the canonical error, so we can do eg. ErrNotFound.Is(err) on something we get back from an external API.
This should *only* be used in clients, not in the server side. The server (abci app / blockchain) should only refer to registered errors
func ABCIInfo ¶
ABCIInfo returns the ABCI error information as consumed by the tendermint client. Returned codespace, code, and log message should be used as a ABCI response. Any error that does not provide ABCICode information is categorized as error with code 1, codespace UndefinedCodespace When not running in a debug mode all messages of errors that do not provide ABCICode information are replaced with generic "internal error". Errors without an ABCICode information as considered internal.
func AssertNil ¶
func AssertNil(err error)
AssertNil panics on error Should be only used with interface methods, which require return error, but the error is always nil
func IsOf ¶
IsOf checks if a received error is caused by one of the target errors. It extends the errors.Is functionality to a list of errors.
func Recover ¶
func Recover(err *error)
Recover captures a panic and stop its propagation. If panic happens it is transformed into a ErrPanic instance and assigned to given error. Call this function using defer in order to work as expected.
func Redact ¶
Redact replaces an error that is not initialized as an ABCI Error with a generic internal error instance. If the error is an ABCI Error, that error is simply returned.
func Wrap ¶
Wrap extends given error with an additional information.
If the wrapped error does not provide ABCICode method (ie. stdlib errors), it will be labeled as internal error.
If err is nil, this returns nil, avoiding the need for an if statement when wrapping a error returned at the end of a function
Example ¶
err1 := Wrap(ErrInsufficientFunds, "90 is smaller than 100") err2 := errors.Wrap(ErrInsufficientFunds, "90 is smaller than 100") fmt.Println(err1.Error()) fmt.Println(err2.Error())
Output: 90 is smaller than 100: insufficient funds 90 is smaller than 100: insufficient funds
func Wrapf ¶
Wrapf extends given error with an additional information.
This function works like Wrap function with additional functionality of formatting the input as specified.
Example ¶
err1 := Wrap(ErrInsufficientFunds, "90 is smaller than 100") err2 := errors.Wrap(ErrInsufficientFunds, "90 is smaller than 100") fmt.Println(err1.Error()) fmt.Println(err2.Error())
Output: 90 is smaller than 100: insufficient funds 90 is smaller than 100: insufficient funds
Types ¶
type Error ¶
type Error struct {
// contains filtered or unexported fields
}
Error represents a root error.
Weave framework is using root error to categorize issues. Each instance created during the runtime should wrap one of the declared root errors. This allows error tests and returning all errors to the client in a safe manner.
All popular root errors are declared in this package. If an extension has to declare a custom root error, always use Register function to ensure error code uniqueness.
func Register ¶
Register returns an error instance that should be used as the base for creating error instances during runtime.
Popular root errors are declared in this package, but extensions may want to declare custom codes. This function ensures that no error code is used twice. Attempt to reuse an error code results in panic.
Use this function only during a program startup phase.
func RegisterWithGRPCCode ¶
func RegisterWithGRPCCode(codespace string, code uint32, grpcCode grpccodes.Code, description string) *Error
RegisterWithGRPCCode is a version of Register that associates a gRPC error code with a registered error.
func (*Error) GRPCStatus ¶
func (e *Error) GRPCStatus() *grpcstatus.Status
func (*Error) Is ¶
Is check if given error instance is of a given kind/type. This involves unwrapping given error using the Cause method if available.
Source Files