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API Reference

Each method can be destructed from the object returned by require('@cucumber/cucumber').

defineParameterType({name, preferForRegexpMatch, regexp, transformer, useForSnippets})

Define a new parameter type and optionally convert an output parameter into something else.

  • name: String used to refer to this type in cucumber expressions.
  • regexp: A regular expression (or array of regular expressions) that match the parameter.
  • transformer: An optional function which transforms the captured argument from a string into what is passed to the step definition. If no transform function is specified, the captured argument is left as a string. The function can be synchronous or return a Promise of the transformed value. The value of this is the current world, so the function can delegate to world functions. Note that your transformer functions cannot reference the world as this if you use arrow functions. See FAQ for details.
  • useForSnippets: Defaults to true. That means this parameter type will be used to generate snippets for undefined steps. If the regexp frequently matches text you don't intend to be used as arguments, disable its use for snippets with false.
  • preferForRegexpMatch: Defaults to false. Set to true if you use regular expressions and you want this parameter type's regexp to take precedence over others during a match.

The built in parameter types are:

  • int
  • float
  • string
    • contained in single or double quotes
    • the transformer removes the quotes
  • word

After([options,] fn)

Defines a hook which is run after each scenario.

  • options: An object with the following keys:
    • tags: String tag expression used to apply this hook to only specific scenarios. See cucumber-tag-expressions for more information.
    • timeout: A hook-specific timeout, to override the default timeout.
  • fn: A function, defined as follows:
    • The first argument will be an object of the form {pickle, gherkinDocument, result, willBeRetried, testCaseStartedId}
      • The pickle object comes from the gherkin library. See testdata/good/*.pickles.ndjson for examples of its structure.
    • When using the asynchronous callback interface, have one final argument for the callback function.

options can also be a string as a shorthand for specifying tags.

Multiple After hooks are executed in the reverse order that they are defined.

AfterAll([options,] fn)

Defines a hook which is run after all scenarios have completed.

  • options: An object with the following keys:
    • timeout: A hook-specific timeout, to override the default timeout.
  • fn: A function, defined as follows:
    • When using the asynchronous callback interface, have one argument for the callback function.

Multiple AfterAll hooks are executed in the reverse order that they are defined.

AfterStep([options,] fn)

Defines a hook which is run after each step.

  • options: An object with the following keys:
    • tags: String tag expression used to apply this hook to only specific scenarios. See cucumber-tag-expressions for more information.
    • timeout: A hook-specific timeout, to override the default timeout.
  • fn: A function, defined as follows:
    • The first argument will be an object of the form {pickle, pickleStep, gherkinDocument, result, testCaseStartedId, testStepId}
      • The pickle object comes from the gherkin library. See testdata/good/*.pickles.ndjson for examples of its structure.
      • The pickleStep is the step in the pickle that this hook has been invoked for
    • When using the asynchronous callback interface, have one final argument for the callback function.

options can also be a string as a shorthand for specifying tags.

Multiple AfterStep hooks are executed in the reverse order that they are defined.

Before([options,] fn)

Defines a hook which is run before each scenario. Same interface as After except the first argument passed to fn will not have the result property.

Multiple Before hooks are executed in the order that they are defined.

BeforeAll([options,] fn)

Defines a hook which is run before all scenarios. Same interface as AfterAll.

Multiple BeforeAll hooks are executed in the order that they are defined.

BeforeStep([options,] fn)

Defines a hook which is run before each step. Same interface as AfterStep except the first argument passed to fn will not have the result property.

Multiple BeforeStep hooks are executed in the order that they are defined.

Given(pattern[, options], fn)

Define a "Given" step.

Aliases: defineStep (deprecated and will be removed in a future release; use the appropriate Given/When/Then keyword to define your step).

  • pattern: A regex or string pattern to match against a gherkin step.
  • options: An object with the following keys:
    • timeout: A step-specific timeout, to override the default timeout.
    • wrapperOptions: Step-specific options that are passed to the definition function wrapper.
  • fn: A function, which should be defined as follows:
    • Should have one argument for each capture in the regular expression.
    • May have an additional argument if the gherkin step has a docstring or data table.
    • When using the asynchronous callback interface, have one final argument for the callback function.

setDefaultTimeout(milliseconds)

Set the default timeout for asynchronous steps. Defaults to 5000 milliseconds.

setDefinitionFunctionWrapper(wrapper)

Note: the usage of setDefinitionFunctionWrapper is discouraged in favor of BeforeStep and AfterStep hooks.

Set a function used to wrap step / hook definitions.

The wrapper function is expected to take 2 arguments:

  • fn is the original function defined for the step - needs to be called in order for the step to be run.
  • options is the step specific wrapperOptions and may be undefined.

Example:

setDefinitionFunctionWrapper(function(fn, options) {
  return function(...args) {
    // call original function with correct `this` and arguments
    // ensure return value of function is returned
    return fn.apply(this, args)
      .catch(error => {
        // rethrow error to avoid swallowing failure
        throw error;
      });
  }
})

When used, the result is wrapped again to ensure it has the same length of the original step / hook definition.

setParallelCanAssign(canAssignFn)

Set the function used to determine if a pickle can be executed based on currently executing pickles.

The canAssignFn function is expected to take 2 arguments:

  • pickleInQuestion is the a pickle we are checking if its okay to run
  • picklesInProgress is an array of pickles currently being executed

And returns true if the pickle can be executed, false otherwise.

See examples in our parallel documentation.

setWorldConstructor(constructor)

Set a custom world constructor, to override the default world constructor:

function World({attach, parameters}) {
  this.attach = attach;
  this.parameters = parameters;
}
  • attach - a function hooks / steps can use to add attachments
  • parameters - world parameters passed in through the cli

Note: The World constructor was made strictly synchronous in v0.8.0.

Then(pattern[, options], fn)

Define a "Then" step. Same interface as Given

When(pattern[, options], fn)

Define a "When" step. Same interface as Given