@basementuniverse/cucumber-tsflow

cucumber-tsflow

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

Fork description

This is a detached fork of https://github.com/timjroberts/cucumber-js-tsflow, including only the ./cucumber-tsflow directory. It has had the https://github.com/wudong/cucumber-js-tsflow/tree/before_after_all_hooks branch merged into it, which adds support for beforeAll and afterAll hooks.

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 beforeEachScenario(): void {
        // This will be called before each scenario
        ...
    }
    ...

    @before("requireTempDir")
    public async beforeEachScenarioRequiringTempDirectory(): Promise<void> {
        // This will be called before each scenario tagged with 'requireTempDir', or before every scenario in features tagged with 'requireTempDir'
        let tempDirInfo = await this.createTempDirectory();

        ...
    }

    @after()
    public afterEachScenario(): void {
        // This will be called after each scenario
        ...
    }

    @after("requireTempDir")
    public afterEachScenarioRequiringTempDirectory(): void {
        // This will be called after each scenario tagged with 'requireTempDir`, or after every scenario in features tagged with 'requireTempDir'
        ...
    }
    
    @beforeAll()
    public static beforeAllScenarios(): void {
        // This will be called before the first scenario
        // It must be a static method
        ...
    }
    
    @afterAll()
    public static afterAllScenarios(): void {
        // This will be called after the last scenario
        // It must be a static method
        ...
    }
}

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;