assert

Documentation

Index

• func Fix(v Fixer, name string, allow_nil bool)
• func Must[T comparable](res T, err error) T
• func MustCall[T any](arg T, fn func(arg T) error, format string, args ...any)
• func New[T interface{ ... }](res T, err error) T
• func NewErrAssertFailed(msg string) error
• func NewErrFixFailed(name string, reason error) error
• func NewErrValidateFailed(name string, reason error) error
• func TODO(msg string)
• func Validate(v Validater, name string, allow_nil bool)
• func WARN(msg string)
• type ErrAssertFailed
  • func (e ErrAssertFailed) Error() string
• type ErrFixFailed
  • func (e ErrFixFailed) Error() string
• type ErrValidateFailed
  • func (e ErrValidateFailed) Error() string
• type Fixer
• type Validater

Functions

func Fix

func Fix(v Fixer, name string, allow_nil bool)

Fix fixes the struct to the closest valid state. Panics with an ErrValidationFailed error if the struct could not be fixed.

Parameters:

• v: The struct to fix.
• name: The name of the struct. If empty, the name "struct" is used.
• allow_nil: Whether to allow the struct to be nil.

Example:

type MyStruct struct {
	Name string
}

func (ms *MyStruct) Fix() error {
	if ms == nil {
		return nil
	}

	if ms.Name == "" {
		return errors.New("name cannot be empty")
	}

	return nil
}

ms := &MyStruct{
	Name: "",
}

Fix(ms, "ms", false) // Panics: (Fix Failed) ms = name cannot be empty

func Must

func Must[T comparable](res T, err error) T

Must is a helper function that wraps a call to a function that returns (T, error) and panics if the error is not nil.

This function is intended to be used to handle errors in a way that is easy to read and write.

Parameters:

• res: The result of the function.
• err: The error returned by the function.

Returns:

• T: The result of the function.

func MustCall

func MustCall[T any](arg T, fn func(arg T) error, format string, args ...any)

MustCall asserts whether the function does not return an error for the given argument. If the function returns an error, it panics with an ErrAssertFailed error.

Parameters:

• arg: The argument to pass to the function.
• fn: The function to execute.
• format: The format of the function call that returned the error.
• args: The arguments of the function call.

func New

func New[T interface{ IsNil() bool }](res T, err error) T

New is a syntactic sugar asserting constructors. It asserts whether the constructor does not return an error and the result is non-nil. If not, it panics with an ErrAssertFailed error.

Parameters:

• res: The result of the constructor.
• inner: The error returned by the constructor.

Example:

type MyStruct struct {}

func (my_struct *MyStruct) IsNil() bool {
	return my_struct == nil
}

func NewMyStruct() (*MyStruct, error) {
	return nil, nil
}

res := New(NewMyStruct()) // Panics: *MyStruct = nil

func NewErrAssertFailed

func NewErrAssertFailed(msg string) error

NewErrAssertFailed creates a new ErrAssertFailed.

Parameters:

• msg: The message of the error.

Returns:

• error: The new error. Never returns nil.

Format:

(Assertion Failed) "<msg>"

where <msg> is the message. If empty, "something went wrong" is used.

func NewErrFixFailed

func NewErrFixFailed(name string, reason error) error

NewErrFixFailed creates a new ErrFixFailed.

Parameters:

• name: The name of the variable.
• reason: The message of the error.

Returns:

• error: The new error. Never returns nil.

Format:

(Fix Failed) "<msg>"

where <msg> is the message. If empty, "something went wrong" is used.

func NewErrValidateFailed

func NewErrValidateFailed(name string, reason error) error

NewErrValidateFailed creates a new ErrValidateFailed.

Parameters:

• name: The name of the variable.
• reason: The message of the error.

Returns:

• error: The new error. Never returns nil.

Format:

(Validate Failed) "<name> = <reason>"

where:

• <name> is the name of the variable. If empty, "struct" is used.
• <reason> is the message of the error.

func TODO

func TODO(msg string)

TODO panics with a TODO message. The given message is appended to the string "TODO: ". If the message is empty, the message "TODO: Handle this case" is used instead.

Parameters:

• msg: The message to append to the string "TODO: ".

This function is meant to be used only when the code is being built or refactored.

func Validate

func Validate(v Validater, name string, allow_nil bool)

Validate asserts whether the struct's inner state is valid. If not, it panics with an ErrValidationFailed error.

Parameters:

• v: The struct to validate.
• name: The name of the struct. If empty, the name "struct" is used.
• allow_nil: Whether to allow the struct to be nil.

Example:

type MyStruct struct {
	Name string
}

func (ms MyStruct) Validate() error {
	if ms.Name == "" {
		return errors.New("name cannot be empty")
	}

	return nil
}

ms := &MyStruct{
	Name: "",
}

Validate(ms, "ms", false) // Panics: (Validate Failed) ms = name cannot be empty

func WARN

func WARN(msg string)

WARN prints a warning message to the console. The message is prefixed with "[WARNING]:" to indicate its nature.

Parameters:

• msg: The warning message to be displayed.

Panics if there is an error writing to the standard output.

Types

type ErrAssertFailed

type ErrAssertFailed struct {
	// Msg describes what went wrong.
	Msg string
}

ErrAssertFailed is an error that is returned when an assertion fails.

func (ErrAssertFailed) Error

func (e ErrAssertFailed) Error() string

Error implements the error interface.

type ErrFixFailed

type ErrFixFailed struct {
	// Name is the name of the variable. If empty, "variable" is used.
	Name string

	// Reason describes what went wrong.
	Reason error
}

ErrFixFailed is an error that is returned when a fix fails.

func (ErrFixFailed) Error

func (e ErrFixFailed) Error() string

Error implements the error interface.

type ErrValidateFailed

type ErrValidateFailed struct {
	// Name is the name of the variable. If empty, "variable" is used.
	Name string

	// Reason describes what went wrong.
	Reason error
}

ErrValidateFailed is an error that is returned when a validation fails.

func (ErrValidateFailed) Error

func (e ErrValidateFailed) Error() string

Error implements the error interface.

type Fixer

type Fixer interface {
	// Fix fixes the struct. Each implementation of Fixer should describe in the
	// comments the conditions under which the struct is valid.
	//
	// Returns:
	//   - error: An error if the struct could not be fixed. Nil otherwise.
	Fix() error
}

Fixer is an interface that defines a method that validates and tries to bring the struct into the closest valid state.

type Validater

type Validater interface {
	// Validate validates the struct. Each implementation of Validater should
	// describe in the comments the conditions under which the struct is valid.
	//
	// Returns:
	//   - error: An error if the struct is invalid. Nil otherwise.
	//
	// NOTES: This method should not modify the struct's state. For that, use
	// Fixer instead.
	Validate() error
}

Validater is an interface that defines a method that checks the struct's inner state/integrity.