Adding rich text block support

[GetOutOfMyBakery]

What

Adding support for Rich Text Blocks:

• resolves: [Feature Request] Rich Text Block Support #184

Rich Text Blocks are a bit unique compared to other blocks:

It is also the output of the Slack client's WYSIWYG message composer, so all messages sent by end-users will have this format. Use this block to include user-defined formatted text in your Block Kit payload. While it is possible to format text with mrkdwn, rich_text is strongly preferred and allows greater flexibility.

Most of the other blocks have separate "compatible block elements" and tend to be relatively shallow, whereas Rich Text Blocks can be "deeply nested" and it's elements have no reuse outside of a rich_text block.

Also added in this PR:

• ./examples/: scripts to generate example message that can either be:
  • directly posted to to Slack
  • copied and pasted to Slack's Block Builder Kit UI to validate the output

This makes it much easier to build confidence in changes being made to the Gem by semi-automating validation against Slack's schema. Since it looks like there's no future opportunity to validate against the JSON schema automatically:

• Block Kit support slackapi/slack-api-specs#18 (and the repo is now archived)

this strategy might be the best solution going forward.

[codecov]

Codecov Report

Attention: Patch coverage is 86.34361% with 31 lines in your changes are missing coverage. Please review.

Project coverage is 96.71%. Comparing base (6de8517) to head (4bb6448).

❗ Current head 4bb6448 differs from pull request most recent head 9bdada9. Consider uploading reports for the commit 9bdada9 to get more accurate results

Files	Patch %	Lines
...k/block_kit/layout/rich_text/rich_text_elements.rb	64.70%	6 Missing ⚠️
...ck_kit/layout/rich_text/rich_text_elements/link.rb	64.70%	6 Missing ⚠️
...kit/layout/rich_text/rich_text_elements/channel.rb	73.33%	4 Missing ⚠️
...ck_kit/layout/rich_text/rich_text_elements/text.rb	73.33%	4 Missing ⚠️
...ck_kit/layout/rich_text/rich_text_elements/user.rb	73.33%	4 Missing ⚠️
...t/layout/rich_text/rich_text_elements/usergroup.rb	73.33%	4 Missing ⚠️
lib/slack/block_kit/blocks.rb	25.00%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #185      +/-   ##
==========================================
- Coverage   99.16%   96.71%   -2.45%     
==========================================
  Files          46       59      +13     
  Lines         962     1189     +227     
==========================================
+ Hits          954     1150     +196     
- Misses          8       39      +31     

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[CGA1123]

Hey @GetOutOfMyBakery -- thanks for taking this on 🙇‍♂️

Let me know when you're happy for a review and I'll get to it as soon as possible.

\cc @dmorgan-fa -- would be keen to hear your feedback on this from, if you're able to begin integrating agains this branch for your use-case.

[dmorgan-fa]

👋 Hey @CGA1123, that's my personal GitHub account and this is my work one 😄

I started on it last night and got into a flow, so it's in pretty good shape just now, but I've not had a chance to validate against Slack's Block Kit Builder yet, since I didn't have access to a workspace from my personal machine.

On an unrelated note, I really appreciated how easy it was to work with your framework! It's really well architected and made it super easy to work on 🙏

[CGA1123]

Ha, in that case syncing up between the both of you should be a breeeeeze! 😄

Glad to hear it! It is a relatively simple (if not quite repetitive) flow, but it's quite cathartic working in some plain old ruby as a change of pace, with a fast test suite to go with it!

---

Will take a look later this evening and have play around with these new block on a Slack workspace 👍

[GetOutOfMyBakery]

I'm happy to do another pass and tidy up the commit history, etc., later but functionality-wise it's looking good. Let me know if there's anything that jumps out at you that you don't like, or if you want to give some pointers about what you want updated before getting it ready to merge.

---

Slightly off-topic but there's a few places that Slack mention some hard limits:

You can include up to 50 blocks in each message [...]

rich_text

Minimum length for the text in this field is 1 and maximum length is 3000 characters.

section_fields, but it applies to rich_text too

It's a small tripping hazard if you're composing complicated messages with lost of rich text elements, or if you're creating single long messages it can be a bit confusing initially.

Is this something you'd be up for gaurding against in the gem, or would you prefer to let Slack respond with the error messaging when limits are exceeded?

[CGA1123]

Is this something you'd be up for gaurding against in the gem, or would you prefer to let Slack respond with the error messaging when limits are exceeded?

This is very much in tune with what was wanted in #176 -- I think that would be quite useful to have, I wonder what the "right" behaviour is in these circumstances, truncations, erroring, some other way of handling it. I think for the time being (in the scope of this PR) we can leave this functionality out. When implemented it would only be useful if consistent across the library I think.

[CGA1123]

Apologies for the delay in getting back to this -- turned out to be a busier end to the week than anticipated.

---

A couple of minor changes to keep behaviour as similar as the Slack API as possible!

FYI -- have dropped ruby 2.6 from the matrix (as EOL) and added 3.3 which required the addition of racc in the Gemfile which is now on master already. Quick rebase should sort bits out and make the build 🟢

Looking fantastic. Appreciate the time taken to work through adding this feature 🙇‍♂️

There are some minor gaps on the spec coverage, although nothing major. Might be nice to have a shared example for RichText::RichTextElements to include into the container objects if time allows -- non-blocking though from my perspective. 👍

[GetOutOfMyBakery]

@CGA1123, no need to apologise, you've been super responsive, don't sweat it.

I've rebased and taken on board your suggestions, take a look from commit Applying Christian's suggested changes 4949baf onwards.

I've:

• updated the main README.md
• added a new ./examples/README.md and updated ./examples/example_helper.rb
• refactored RichTextElements::StyleHelper to make it a bit easier to work with
• increased spec coverage and used shared_examples where appropriate

I've not:

• tested posting directly to Slack with ./examples scripts
• tidied up the commit history (happy to tidy it up or squash it once you're happy with the PR)

[CGA1123]

Build failures are unrelated (codecov being unhappy for some reason), specs all running fine 👍

I've tested out posting directly to slack and it's working a charm as best I can tell -- really like this addition of the examples/ and related helpers (also TIL [!TIP] and [!NOTE]) 👏

Quick squash of commits + an entry to CHANGELOG would be much appreciated and I'll get this merged and released. Nice one 🚀

[GetOutOfMyBakery]

Thanks @CGA1123, great to have confirmation that the examples scripts are posting to Slack as expected 🙏

There's a few others: [!IMPORTANT], [!WARNING], [!CAUTION], they're still relatively new see here.

I've squashed it all down, updated the CHANGELOG, and applied the $stderr change you'd suggested 👍

Thanks for the fast feedback and turn around on this 🙏

[CGA1123]

Thanks for contributing @GetOutOfMyBakery 🙇‍♂️

This has now shipped out in v0.24.0