Declare pp dependency of RBS signatures and validate them in CI

.github/workflows/main.yml

@@ -55,6 +55,8 @@ jobs:
       run: bundle exec rake typecheck:tapioca typecheck:sorbet
     - name: Check Steep
       run: bundle exec rake typecheck:steep
+    - name: Validate RBS
+      run: bundle exec rake typecheck:rbs
     - name: Check field kinds
       run: rm lib/prism/node.rb && CHECK_FIELD_KIND=true bundle exec rake
 

prism.gemspec

@@ -200,6 +200,7 @@ Gem::Specification.new do |spec|
     "sig/generated/prism/parse_result/comments.rbs",
     "sig/generated/prism/parse_result/errors.rbs",
     "sig/generated/prism/parse_result/newlines.rbs",
+    "sig/manifest.yaml",
     "src/arena.c",
     "src/buffer.c",
     "src/char.c",

rakelib/typecheck.rake

@@ -337,6 +337,21 @@ namespace :typecheck do
     end
   end
 
+  desc "Validate the RBS signatures shipped with the gem"
+  task rbs: :templates do
+    with_gemfile do
+      require "yaml"
+
+      # Load only what users of the gem get: sig/generated and the standard
+      # libraries declared in sig/manifest.yaml. sig/_shims is not shipped
+      # with the gem, so it must not be used here.
+      dependencies = YAML.safe_load_file("sig/manifest.yaml").fetch("dependencies", [])
+      libraries = dependencies.flat_map { |dependency| ["-r", dependency.fetch("name")] }
+
+      sh "bundle", "exec", "rbs", "-I", "sig/generated", *libraries, "validate"
+    end
+  end
+
   desc "Generate RBIs with Tapioca"
   task tapioca: :templates do
     Rake::Task["compile:prism"].invoke

sig/manifest.yaml

@@ -0,0 +1,2 @@
+dependencies:
+  - name: pp