feat: slack client to support multiple org

[ekremney]

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[github-actions]

This PR will trigger a minor release when merged.

[solaris007]

i'd propose to split the client-factory part from the actual slack client. this aligns with the principle of single responsibility, ensuring that each client instance is dedicated to a specific target (i.e., a Slack workspace). This redesign would simplify the client interface by removing the need to specify the target for every public method call.

Incomplete example:

class SlackClientFactory {
  constructor(log) {
    this.clients = {};
    this.log = log;
  }

  // createFrom / lambda context handling here...

  getClientForTarget(target) {
    if (!this.clients[target]) {
      const token = this.getTokenForTarget(target);
      if (!token) {
        throw new Error(`No token found for target: ${target}`);
      }
      this.clients[target] = new SlackClient(token, this.log);
    }
    return this.clients[target];
  }

  getTokenForTarget(target) {
    return process.env[`${ENV_PREFIX}${target}`];
  }
}

class SlackClient {
  constructor(token, log) {
    this.client = new WebClient(token);
    this.log = log;
  }

  async postMessage(message, opts = {}) {
    try {
      const result = await this.client.chat.postMessage({
        ...DEFAULT_PARAMS,
        text: message,
        ...opts,
      });

      return {
        channelId: result.channel,
        threadId: result.ts,
      };
    } catch (error) {
      this.log.error('Slack message failed to send');
      throw error;
    }
  }
}

this also benefits security:

• a client only can deal with one workspace and not accidentally others
• it is ground work for later adding roles, i.e. clients backed by different scoped slack tokens, for example a privileged client that can create channels, while regular clients only send messages, etc.

[ekremney]

I incorporated all the reviews and added the file upload method. Please re-review

[solaris007]

LGTM, only minor comments

[adobe-bot]

🎉 This PR is included in version @adobe/spacecat-shared-slack-client-v1.0.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

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