Serverless Workflow Specification - Typescript SDK

Provides the Typescript API/SPI for the Serverless Workflow Specification

With the SDK you can:

Parse workflow JSON and YAML definitions
Programmatically build workflow definitions
Validate workflow definitions

Status

Latest Releases	Conformance to spec version
v1.0.0	v0.6
v2.0.0	v0.7
v3.0.0	v0.8

Getting Started

Building locally

To build the project and run tests locally:

git clone https://github.com/serverlessworkflow/sdk-typescript.git
cd sdk-typescript
npm install && npm run build && npm run test

How to use

Install

Version >= 4.0.0

Note: Version 4.0.0 has not been released yet.

npm i @serverlessworkflow/sdk-typescript

Version < 4.0.0

npm i @severlessworkflow/sdk-typescript

Create Workflow using builder API

import { workflowBuilder, injectstateBuilder, Specification } from '@serverlessworkflow/sdk-typescript';

const workflow: Specification.Workflow = workflowBuilder()
  .id("helloworld")
  .specVersion("0.8")
  .version("1.0")
  .name("Hello World Workflow")
  .description("Inject Hello World")
  .start("Hello State")
  .states([
    injectstateBuilder()
      .name("Hello State")
      .data({
          "result": "Hello World!"
      })
      .build()
  ])
  .build();

Create Workflow from JSON/YAML source

import { Specification, Workflow } from '@serverlessworkflow/sdk-typescript';

const source = `id: helloworld
version: '1.0'
specVerion: '0.8'
name: Hello World Workflow
description: Inject Hello World
start: Hello State
states:
  - type: inject
    name: Hello State
    data:
      result: Hello World!
    end: true`

const workflow: Specification.Workflow = Workflow.fromSource(source);

Where source can be in both JSON or YAML format.

Parse a Workflow instance to JSON/YAML

Having the following workflow instance:

import { workflowBuilder, injectstateBuilder, Specification } from '@serverlessworkflow/sdk-typescript';

const workflow: Specification.Workflow = workflowBuilder()
  .id("helloworld")
  .version("1.0")
  .specVersion("0.8")
  .name("Hello World Workflow")
  .description("Inject Hello World")
  .start("Hello State")
  .states([
    injectstateBuilder()
      .name("Hello State")
      .data({
        "result": "Hello World!"
      })
      .end(true)
      .build()
  ])
  .build();

You can convert it to its string representation in JSON or YAML format by using the static methods Workflow.toJson or Workflow.toYaml respectively:

import {Specification, workflowBuilder} from "@severlessworkflow/sdk-typescript";

const workflow: Specification.Workflow = workflowBuilder()
    //...
    .build()

const workflowAsJson: string = Specification.Workflow.toJson(workflow);

import {Specification, workflowBuilder} from "@severlessworkflow/sdk-typescript";

const workflow: Specification.Workflow = workflowBuilder()
    //...
    .build()

const workflowAsYaml: string = Specification.Workflow.toYaml(workflow);

Validate workflow definitions

The sdk provides a way to validate if a workflow object is compliant with the serverlessworkflow specification.

WorkflowValidator class provides a validation method:

validate(): boolean

import {WorkflowValidator, Specification} from '@serverlessworkflow/sdk-typescript';
import {Workflow} from "./workflow";

const workflow = {
    id: 'helloworld',
    version: '1.0',
    specVersion: '0.3',
    name: 'Hello World Workflow',
    description: 'Inject Hello World',
    start: 'Hello State',
    states: [
        {
            type: 'inject',
            name: 'Hello State',
            end: true,
            data: {
                result: "Hello World!"
            }
        }
    ]
};

const workflowValidator: WorkflowValidator = new WorkflowValidator(Workflow.fromSource(JSON.stringify(workflow)));
if (!workflowValidator.isValid) {
    workflowValidator.errors.forEach(error => console.error((error as ValidationError).message));
}

You can also validate parts of a workflow using validators:

import { ValidateFunction } from 'ajv';
import { validators, Specification } from '@serverlessworkflow/sdk-typescript';

const injectionState: Specification.Injectstate = workflow.states[0];
const injectionStateValidator: ValidateFunction<Specification.Injectstate> = validators.get('Injectstate');
if (!injectionStateValidator(injectionState)) {
  injectionStateValidator.errors.forEach(error => console.error(error.message));
}

Generate workflow diagram

It is possible to generate the workflow diagram with Mermaid

const workflow = workflowBuilder()
    .id("helloworld")
    ....
    .build();

const mermaidSourceCode = new MermaidDiagram(workflow).sourceCode();

Here you can see a full example that uses mermaid in the browser to generate the workflow diagram.

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