---
name: "heckle"
section: "1"
platform: "linux"
package: "ruby-heckle"
version: "1.4.3-4"
release: "Debian 7 (Wheezy)"
platforms: ["linux"]
url: "https://new.carta.tech/heckle"
---

# heckle(1)

mutate Ruby code and run test

## NAME

heckle - mutate Ruby code and run test

## SYNOPSIS

**heckle** *class\_name* \[*method\_name*\]

## DESCRIPTION

\`heckle' is a mutation tester. It modifies your code and runs your tests to make sure they fail. The idea is that if code can be changed and your tests don't notice, either that code isn't being covered or it doesn't do anything.

- **-v**, **--verbose**

  Loudly explain heckle run

- **-V**, **--version**

  Prints Heckle's version number

- **-t**, **--tests** TEST\_PATTERN

  Location of tests (glob)

- **-F**, **--force**

  Ignore initial test failures

  Best used with **--focus**

- **--assignments**

  Only mutate assignments

- **-b**, **--branches**

  Only mutate branches

- **-f**, **--focus**

  Apply the eye of sauron

- **-T**, **--timeout** SECONDS

  The maximum time for a test run in seconds

  Used to catch infinite loops

- **-n**, **--nodes** NODES

  Nodes to mutate

  Possible values: call, cvasgn ,dasgn, dasgn\_curr, false, gasgn, iasgn, if, iter, lasgn, lit, str, true, until, while

- **-x**, **--exclude-nodes** NODES

  Nodes to exclude

- **-h**, **--help**

  Show this message