errhelp

Documentation

Overview

Package errhelp contains error helper functions.

Index

• func FirstError(errs ...error) error
• func TimeoutOrFirstError(ctx context.Context, errs ...error) error

Examples

• FirstError
• TimeoutOrFirstError

Functions

func FirstError

func FirstError(errs ...error) error

FirstError gets the first error in errs that is non-nil, or nil if none exist.

Example

ExampleFirstError is a testable example for FirstError.

package main

import (
	"errors"
	"fmt"

	"github.com/c4-project/c4t/internal/helper/errhelp"
)

func main() {
	fmt.Println("FirstError() == nil:", errhelp.FirstError() == nil)

	fmt.Println("FirstError(x, y) ==", errhelp.FirstError(errors.New("x"), errors.New("y")))

}

Output:

FirstError() == nil: true
FirstError(x, y) == x

func TimeoutOrFirstError

func TimeoutOrFirstError(ctx context.Context, errs ...error) error

TimeoutOrFirstError returns ctx.Err() if it is a deadline-exceeded error, or the first error in errs that is non-nil, if any exist.

Example

ExampleTimeoutFirstError is a testable example for FirstError.

package main

import (
	"context"
	"errors"
	"fmt"

	"github.com/c4-project/c4t/internal/helper/errhelp"
)

func main() {
	ctx := context.Background()
	fmt.Println("TimeoutOrFirstError(ok ctx) ==", errhelp.TimeoutOrFirstError(ctx))
	fmt.Println("TimeoutOrFirstError(ok ctx, x, y) ==", errhelp.TimeoutOrFirstError(ctx, errors.New("x"), errors.New("y")))

	tctx, cf := context.WithTimeout(ctx, 0)
	defer cf()
	fmt.Println("TimeoutOrFirstError(t/o ctx) ==", errhelp.TimeoutOrFirstError(tctx))
	fmt.Println("TimeoutOrFirstError(t/o ctx, x, y) ==", errhelp.TimeoutOrFirstError(tctx, errors.New("x"), errors.New("y")))

}

Output:

TimeoutOrFirstError(ok ctx) == <nil>
TimeoutOrFirstError(ok ctx, x, y) == x
TimeoutOrFirstError(t/o ctx) == context deadline exceeded
TimeoutOrFirstError(t/o ctx, x, y) == context deadline exceeded