Modernize reveal-ck for Ruby 3.3

[jedcn]

Context

reveal-ck targets Ruby 2.5–2.7 (last released Feb 2020). The dev container was updated to Ruby 3.3, which makes bundle install fail immediately because listen = 3.2.1 (exact pin) declares ruby < 3.A. Several gem major versions also have breaking API changes requiring application code changes.

Goal: Modernize everything — Ruby version, all gems to latest, application code updated for new APIs, all tests passing — via a series of small PRs against a modernize-ruby base branch that eventually merges to master.

End state: bundle install works, bundle exec rake ci (spec + rubocop + cucumber) all green on Ruby 3.3.

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7 Ordered PRs Against modernize-ruby

PR 1 — Upgrade RuboCop to 1.x and reset config

Why first: RuboCop 1.x refuses to load a 0.60-era .rubocop.yml. Zero runtime impact.

Files:

• reveal-ck.gemspec — rubocop dev dep: ~> 0.60 → ~> 1.60
• .rubocop.yml — rewrite for 1.x: add AllCops: NewCops: disable, add AllCops: TargetRubyVersion: 3.3, remove Gemspec/RequiredRubyVersion block (renamed in 1.x), keep existing metric/style exclusions

Verify: bundle exec rake rubocop passes.

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PR 2 — Bump safe gem dependencies; unblock bundle install

Why second: Unpins versions blocking Ruby 3.3. Excludes gems with breaking API changes (html-pipeline, haml, rack) — those get their own PRs paired with code changes.

Files — reveal-ck.gemspec:

• required_ruby_version: >= 2.5 → >= 3.1
• listen: 3.2.1 → ~> 3.9
• rack-livereload: 0.3.17 → ~> 0.6
• tilt: 2.0.9 → ~> 2.4
• guard: ~> 2.16 → ~> 2.19
• docile: ~> 1.3 → ~> 1.4
• gemoji: ~> 3.0 → ~> 4.1
• slim: ~> 4.0 → ~> 5.0
• kramdown: ~> 2.1 → ~> 2.5
• .ruby-version — 2.7.0 → 3.3.0

Verify: bundle install succeeds.

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PR 3 — Fix Ruby 3.x language-level issues

Why third: Clean language baseline before harder API migrations — so failures in PRs 4/5/6 are unambiguous.

Files:

• lib/reveal-ck/config.rb — replace Config < OpenStruct with a hash-backed @data implementation using method_missing/respond_to_missing?. OpenStruct is deprecated in Ruby 3.2+ and may be removed in 3.4. Preserve public interface: config.attr, config.attr=, config.to_h, config.merge!, config[key], config[key]=. Also fix each_pair → each.
• lib/reveal-ck/builders/slides_builder.rb — YAML.load_file → YAML.safe_load_file(file, permitted_classes: [Symbol]) (raises Psych::DisallowedClass in Ruby 3.1+)
• lib/reveal-ck/presentation_dsl.rb (×2) and lib/reveal-ck/render/contents_of.rb — File.open(path).read → File.read(path)

Verify: bundle exec rake spec — all 37 spec files pass.

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PR 4 — Migrate html-pipeline from 2.x to 3.x

Why fourth: Most invasive change; core generation path. html-pipeline 3.x migrated from Nokogiri to Selma with a completely redesigned filter API. MentionFilter and AutolinkFilter were removed from the gem — those features are dropped.

Files:

• reveal-ck.gemspec: html-pipeline ~> 2.12 → ~> 3.0
• lib/html/pipeline/reveal_ck_emoji_filter.rb — complete rewrite. In 3.x, filters are plain objects implementing call(input_hash) returning modified hash. Context passed at construction via initialize(context = {}). Use regex-based emoji replacement.
• lib/reveal-ck/filtered_html_string.rb — update call from pipeline.call(html, config) → pipeline.call(html); remove config from constructor args.
• lib/reveal-ck/builders/create_slides_html.rb — update filter construction to pass initialized instances with context: filters = filter_classes.map { |k| k.new(config.to_h) }
• lib/reveal-ck/config.rb — remove MentionFilter/AutolinkFilter from default filter list; default becomes ['HTML::Pipeline::RevealCKEmojiFilter'] only

Tests:

• spec/lib/html/pipeline/reveal_ck_emoji_filter_spec.rb — rewrite for call(input_hash) interface
• spec/lib/reveal-ck/config_spec.rb — update default filters assertion
• features/mention.feature — delete (MentionFilter removed from gem)
• features/auto-link.feature — delete (AutolinkFilter removed from gem)

Verify: bundle exec rake spec passes. bundle exec cucumber passes. features/emoji.feature passes.

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PR 5 — Upgrade Haml from 5.x to 6.x

Files:

• reveal-ck.gemspec: haml ~> 5.1 → ~> 6.0
• lib/reveal-ck/tilt/config.rb — ensure require 'tilt/haml' is present (haml 6 + tilt 2.4 need explicit load)
• Audit .haml templates in files/reveal-ck/templates/ for escape_html breakage (haml 6 defaults escape_html: true); bundled templates use no raw HTML interpolation so this should be fine

Verify: bundle exec cucumber features/generate-with-haml.feature passes.

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PR 6 — Upgrade Rack from 2.x to 3.x; add rackup gem

Why sixth: Only affects the serve command; isolated. Rack 3.x extracted Rack::Server into a separate rackup gem.

Files:

• reveal-ck.gemspec: rack ~> 2.2 → ~> 3.0; add s.add_dependency 'rackup', '~> 2.1'
• lib/reveal-ck/commands/start_web_server.rb — add require 'rackup'; Rack::Server.new(...) → Rackup::Server.new(...)
• spec/lib/reveal-ck/commands/start_web_server_spec.rb — add require 'rackup'; update mock from Rack::Server → Rackup::Server

Verify: bundle exec rake spec passes. bundle exec cucumber features/serve.feature passes.

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PR 7 — Update dev dependencies, CI config, and final cleanup

Files:

• reveal-ck.gemspec dev deps: bump aruba (> 2.2), cucumber (> 9.x), add activesupport version constraint (~> 7.1), remove relish (abandoned since 2014)
• .travis.yml — update Ruby test matrix to 3.1, 3.2, 3.3 (or replace with GitHub Actions)
• Update s.date in gemspec

Verify: Full bundle exec rake ci passes green on Ruby 3.3.

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Behavior Change

mention and auto-link features dropped: html-pipeline 3.x removed MentionFilter and AutolinkFilter. The corresponding Cucumber acceptance tests (mention.feature, auto-link.feature) are deleted in PR 4. Users who relied on these filters can implement custom filter classes.

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File → PR Mapping

File	PR
.rubocop.yml	1
reveal-ck.gemspec	1, 2, 4, 5, 6, 7
.ruby-version	2
lib/reveal-ck/config.rb	3, 4
lib/reveal-ck/builders/slides_builder.rb	3
lib/reveal-ck/presentation_dsl.rb	3
lib/reveal-ck/render/contents_of.rb	3
lib/html/pipeline/reveal_ck_emoji_filter.rb	4
lib/reveal-ck/filtered_html_string.rb	4
lib/reveal-ck/builders/create_slides_html.rb	4
lib/reveal-ck/tilt/config.rb	5
lib/reveal-ck/commands/start_web_server.rb	6
spec/lib/html/pipeline/reveal_ck_emoji_filter_spec.rb	4
spec/lib/reveal-ck/config_spec.rb	4
spec/lib/reveal-ck/commands/start_web_server_spec.rb	6
features/mention.feature	4 (delete)
features/auto-link.feature	4 (delete)