ログの他メッセージへのリンク

Slack の発言への permalink があった場合に、ログの該当発言へのリンクにしたい。

attachment には以下のような感じの JSON が入っているが、現状 struct に対応するキーがなくて JSON 変換時に欠落しているので、これを足してその後 html に反映させると良さそう。

{
    "from_url": "https://vim-jp.slack.com/archives/CXXXXXXXX/p1584589830473300",
    "fallback": "[March 18th, 2020 8:50 PM] user_name: hi",
    "ts": "1584589830.473300",
    "author_id": "UXXXXXXXX",
    "author_subname": "user_name",
    "channel_id": "CXXXXXXXX",
    "channel_name": "ch_name",
    "is_msg_unfurl": true,
    "text": "hi",
    "author_name": "user_name",
    "author_link": "https://vim-jp.slack.com/team/UXXXXXXXX",
    "author_icon": "https://avatars.slack-edge.com/2019-11-03/xxx.png",
    "mrkdwn_in": [
        "text"
    ],
    "id": 1,
    "original_url": "https://vim-jp.slack.com/archives/CXXXXXXXX/p1584589830473300",
    "footer": "Posted in #ch_name"
}

Locate the attachment struct and the HTML rendering path for Slack log messages. Start by tracing how attachment JSON is decoded, then verify that the permalink is retained and rendered as a link to the referenced message in the generated HTML.