pre-post-run-workflow-plugin.md

Pre/Post Run Workflow Plugin

The Pre/Post Run Workflow Plugin allows you to execute custom logic before or after running a workflow. This plugin is useful for modifying workflows, validating inputs, saving results, sending notifications, etc.

Usage

To create a Pre/Post Run Workflow Plugin, you need to implement the ExecutablePlugin interface and register your plugin.

Example

Here is an example of a Pre-Run Workflow Plugin:

import { AbstractPlugin, ExecutablePlugin, PRE_RUN_WORKFLOW_PLUGIN } from '@letrun/core';
import { Workflow } from '@letrun/common';

export default class PreRunWorkflowPlugin extends AbstractPlugin implements ExecutablePlugin {
  readonly name = 'validate-workflow';
  readonly type = PRE_RUN_WORKFLOW_PLUGIN;

  async execute(input: { workflow: Workflow }) {
    const { workflow } = input;
    if (!workflow.name.startsWith('coolday-')) {
      throw new Error('Workflow name must start with "coolday-"');
    }
  }
}

Here is an example of a Post-Run Workflow Plugin:

import { AbstractPlugin, ExecutablePlugin, POST_RUN_WORKFLOW_PLUGIN } from '@letrun/core';
import { Workflow } from '@letrun/common';
import fs from 'fs';

export default class PostRunWorkflowPlugin extends AbstractPlugin implements ExecutablePlugin {
  readonly name = 'save-successful-workflow';
  readonly type = POST_RUN_WORKFLOW_PLUGIN;

  async execute(input: { workflow: Workflow; result: any; error: any }) {
    const { workflow, result } = input;
    if (workflow.status === 'completed') {
      await fs.promises.writeFile(`./results/${workflow.name}.json`, JSON.stringify(result));
    }
  }
}

Registering the Plugin

To register the Pre/Post Run Workflow Plugin, place it in the plugins directory (or the directory specified in your configuration) and ensure it is loaded by the CLI tool.

Output

Whenever a workflow is run, it'll be failed if the workflow name does not start with coolday-. If the workflow is successful, the result will be saved to a file in the results directory.

Summary

The Pre/Post Run Workflow Plugin allows you to extend the CLI tool with custom logic before or after running workflows using the ExecutablePlugin interface. Implement the ExecutablePlugin interface, register your plugin, and place it in the appropriate directory to use it.