cucumber-tsflow

Provides 'specflow' like bindings for CucumberJS in TypeScript 1.7+.

Bindings

Bindings provide the automation that connects a specification step in a Gherkin feature file to some code that executes for that step. When using Cucumber with TypeScript you can define this automation using a 'binding' class:

import { binding } from "cucumber-tsflow";
 
@binding()
class MySteps {
    ...
}
 
export = MySteps;

Note: You must use the export = <type>; because Cucumber expects exports in this manner.

Step Definitions

Step definitions can be bound to automation code in a 'binding' class by implementing a public function that is bound with a 'given', 'when' or 'then' binding decorator:

import { binding, given, when then } from "cucumber-tsflow";
 
@binding()
class MySteps {
    ...
    @given(/I perform a search using the value "([^"]*)"/)
    public givenAValueBasedSearch(searchValue: string): void {
        ...
    }
    ...
}
 
export = MySteps;

The function follows the same requirements of functions you would normally supply to Cucumber which means that the functions may be synchronous by returning nothing, use the callback, or return a Promise<T>. Additionally, the function may also be async following the TypeScript async semantics.

Step definitions may also be scoped at a tag level by supplying an optional tag name when using the binding decorators:

@given(/I perform a search using the value "([^"]*)"/)
public givenAValueBasedSearch(searchValue: string): void {
    ...
    // The default step definition
    ...
}
 
@given(/I perform a search using the value "([^"]*)"/, "tagName")
public givenAValueBasedSearch(searchValue: string): void {
    ...
    // The step definition that will execute if the feature or
    // scenario has the @tagName defined on it
    ...
}

Hooks

Hooks can be used to perform additional automation on specific events such as before or after scenario execution. Hooks can be restricted to run for only features or scenarios with a specific tag:

import { binding, before, after } from "cucumber-tsflow";
 
@binding()
class MySteps {
    ...
    @before()
    public beforeAllScenarios(): void {
        ...
    }
    ...
 
    @before("requireTempDir")
    public async beforeAllScenariosRequiringTempDirectory(): Promise<void> {
        let tempDirInfo = await this.createTemporaryDirectory();
 
        ...
    }
 
    @after()
    public afterAllScenarios(): void {
        ...
    }
 
    @after("requireTmpDir")
    public afterAllScenarios(): void {
        ...
    }
}
 
export = MySteps;

Sharing Data between Bindings

Context Injection

Like 'specflow', cucumber-tsflow supports a simple dependency injection framework that will instantitate and inject class instances into 'binding' classes for each execuing scenario.

To use context injection:

• Create simple classes representing the shared data (they must have default constructors)
• Define a constructor on the 'binding' classes that will require the shared data that accepts the context objects as parameters
• Update the @binding() decorator to indicate the types of context objects that are required by the 'binding' class

import { binding, before, after } from "cucumber-tsflow";
import { Workspace } from "./Workspace";
 
@binding([Workspace])
class MySteps {
    constructor(protected workspace: Workspace)
    { }
 
    @before("requireTempDir")
    public async beforeAllScenariosRequiringTempDirectory(): Promise<void> {
        let tempDirInfo = await this.createTemporaryDirectory();
 
        this.workspace.updateFolder(tempDirInfo);
    }
}
 
export = MySteps;