command module
Version: v0.0.0-...-fc21f61 Latest Latest

This package is not in the latest version of its module.

Go to latest
Published: Nov 25, 2022 License: Apache-2.0 Imports: 9 Imported by: 0



Build Status

An implementation of failpoints for golang. Please read design.md for a deeper understanding.

Add a failpoint

Failpoints are special comments that include a failpoint variable declaration and some trigger code,

func someFunc() string {
	// gofail: var SomeFuncString string
	// // this is called when the failpoint is triggered
	// return SomeFuncString
	return "default"

Build with failpoints

Building with failpoints will translate gofail comments in place to code that accesses the gofail runtime.

Call gofail in the directory with failpoints to generate gofail runtime bindings, then build as usual,

gofail enable
go build cmd/

The translated code looks something like,

func someFunc() string {
        if vSomeFuncString, __fpErr := __fp_SomeFuncString.Acquire(); __fpErr == nil { defer __fp_SomeFuncString.Release(); SomeFuncString, __fpTypeOK := vSomeFuncString.(string); if !__fpTypeOK { goto __badTypeSomeFuncString}
		// this is called when the failpoint is triggered
		return SomeFuncString; __badTypeSomeFuncString: __fp_SomeFuncString.BadType(vSomeFuncString, "string"); };
        return "default"

To disable failpoints and revert to the original code,

gofail disable

Triggering a failpoint

After building with failpoints enabled, the program's failpoints can be activated so they may trigger when evaluated.

Command line

From the command line, trigger the failpoint to set SomeFuncString to hello,

GOFAIL_FAILPOINTS='my/package/path/SomeFuncString=return("hello")' ./cmd

Multiple failpoints are set by using ';' for a delimiter,

GOFAIL_FAILPOINTS='failpoint1=return("hello");failpoint2=sleep(10)' ./cmd
HTTP endpoint

First, enable the HTTP server from the command line,

GOFAIL_HTTP="" ./cmd

Activate a failpoint with curl,

$ curl -XPUT -d'return("hello")'

List the failpoints,

$ curl

Deactivate a failpoint,

$ curl -XDELETE
Unit tests

From a unit test,

import (

	gofail "go.etcd.io/gofail/runtime"

func TestWhatever(t *testing.T) {
	gofail.Enable("my/package/path/SomeFuncString", `return("hello")`)
	defer gofail.Disable("my/package/path/SomeFuncString")



gofail is a tool for enabling/disabling failpoints in go code.

Source Files


Path Synopsis

Jump to

Keyboard shortcuts

? : This menu
/ : Search site
f or F : Jump to
y or Y : Canonical URL