pre-post-run-task-plugin.md

Pre/Post Run Task Plugin

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

Usage

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

Example

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

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

export default class PreRunTaskPlugin extends AbstractPlugin implements ExecutablePlugin {
  readonly name = 'validate-task';
  readonly type = PRE_RUN_TASK_PLUGIN;

  async execute(input: { workflow: Workflow; task: Task }) {
    const { task } = input;
    if (!task.name.startsWith('collday-')) {
      throw new Error(`Task name must start with 'collday-'. Task name: ${task.name}`);
    }
  }
}

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

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

export default class PostRunTaskPlugin extends AbstractPlugin implements ExecutablePlugin {
  readonly name = 'save-successful-task';
  readonly type = POST_RUN_TASK_PLUGIN;

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

Registering the Plugin

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

Output

If any task is executed that does not start with collday-, the Pre-Run Task Plugin will throw an error. And after the task is executed successfully, the Post-Run Task Plugin will save the result to a file in the results directory.

Summary

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