actionpack: type the routing Mapper DSL by apiology · Pull Request #1106 · ruby/gem_rbs_collection

apiology · 2026-10-19T17:50:37Z

Claude: This PR was written by Claude Code on behalf of @apiology.

Problem:

Route files type-check against untyped, so routing mistakes pass:

Rails.application.routes.draw do
  # no error, though Rails rejects a Symbol `to:` when it loads the routes
  get "recent", to: :recent
  resources :photos do
    # untyped, though Rails returns the block value
    new { 1 }.succ
  end
end

This covers the public ActionDispatch::Routing::Mapper DSL in 7.2 and 8.1.

Solution: Declare the DSL in actiondispatch.rbs from mapper.rb (v7.2.4, v8.1.4), moving each generated declaration's Rails documentation with it:

Aliases and interfaces in Mapper name what Mapping, Resource and Scope accept: paths, via, format, only/except, to (strings, Rack apps, lambdas, controller classes), constraints (hashes, matches? objects, request lambdas) and on.
Overloads cover the "path" => "controller#action" and App => "path" hash forms, and concern with a lambda, callable or block. The verbs, match and mount drop the block, which Rails never calls.
Returns: the mapper for resources, scope and the verbs; the block value for collection, member, new, shallow, controller and defaults; in 8.1, the path array for match and root, which end in path_or_actions.each.

mount keeps an untyped app, since engine classes respond to call only through railties. 6.0 is unchanged, per gems/actionpack/README.md.

In Rails 6.0 through 8.1, Mapper::Resources#new yields through with_scope_level and path_scope, each of which returns the block's value. Replace the generated untyped signature with a generic one in actiondispatch.rbs, and test it in the 7.2 and 8.1 suites. Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]> Claude-Session: https://claude.ai/code/session_01SEntZKsZwQHhzqcwG7MTqn

gems/actionpack/README.md accepts changes only for Rails versions under maintenance, and 6.0 is not one, so restore its RBS. Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]> Claude-Session: https://claude.ai/code/session_01SEntZKsZwQHhzqcwG7MTqn

In Rails 7.2 and 8.1 the Mapper DSL methods either return the mapper (resource, resources, nested, namespace, scope, constraints, the HTTP verb helpers, mount, with_default_scope, and match/root in 7.2) or the value of their block (collection, member, shallow, controller, defaults), because they end in `self` or in `yield` through with_scope_level, path_scope and shallow_scope. The generated signatures returned untyped and required blocks on match (7.2) and concern, which also accepts a callable. In 8.1, Resources#match returns its path_or_actions array (it ends in `path_or_actions.each`), and root returns match's value, so both are typed as Array. Concerns#concerns likewise ends in `each`. Move these declarations out of actionpack-generated.rbs into actiondispatch.rbs, add the missing 7.2 HttpHelpers#options, and cover them in the 7.2 and 8.1 route-drawing tests. Sources: actionpack/lib/action_dispatch/routing/mapper.rb at v7.2.4 and v8.1.4. Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]> Claude-Session: https://claude.ai/code/session_01SEntZKsZwQHhzqcwG7MTqn

The previous commit dropped the Rails doc comments of the declarations it moved out of actionpack-generated.rbs and typed only return values. Move each doc comment onto its hand-written declaration, and type the arguments, options and blocks from mapper.rb at v7.2.4 and v8.1.4: - Type aliases and interfaces in Mapper name the option values that Mapping, Resource and Scope accept: paths, `via`, `format`, `only`/`except`, `to` endpoints (strings, Rack apps and lambdas, controller classes), constraints (hashes, `matches?` objects and request lambdas), and `on`. - `get`..`connect`, `match` and `mount` gain an overload for the `"path" => "controller#action"` and `App => "path"` hash forms, and drop the block Rails never calls. - `concern` gets overloads for a lambda, a callable object, or a block run on the mapper. - 8.1 also moves mount, options and connect out of the generated file. In 7.2 the verbs and match take several paths and match/root return the mapper; in 8.1 they take one path and match/root return the path array. The tests draw routes in the forms the Rails routing guide uses. Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]> Claude-Session: https://claude.ai/code/session_01SEntZKsZwQHhzqcwG7MTqn

concern with a block stores and returns the same mapper lambda shape as concern with a lambda, so type both overloads alike. Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]> Claude-Session: https://claude.ai/code/session_01SEntZKsZwQHhzqcwG7MTqn

github-actions · 2026-10-19T18:31:19Z

@apiology Thanks for your contribution!

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See also: https://github.com/ruby/gem_rbs_collection/blob/main/docs/CONTRIBUTING.md

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You changed RBS files for an existing gem.
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@ksss, @tk0miya, please review this pull request.
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ruby/gem_rbs_collection#1106 may not merge soon, so on Rails 7.2 and later castwide/solargraph master still reports undefined for Mapper::Resources#new. Move its generic annotation out of rails_before_7_2 into the unscoped annotations, with a note to remove it once #1106 is released and the collection revision is bumped. Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]> Claude-Session: https://claude.ai/code/session_01SEntZKsZwQHhzqcwG7MTqn

* Type routing Resources#new as the block value Mapper::Resources#new returns its block's value (path_scope yields it). The routes expectation of self came from the YARD gem mapper, which types every method named new as self; castwide/solargraph#1378 maps gems from source, so master reports undefined. ruby/gem_rbs_collection#1106 types it as [T] () { () -> T } -> T in the actionpack 7.2 and 8.1 RBS. Rails 7.0 and 7.1 resolve the 6.0 RBS, which that repo leaves unchanged, so add the same generic signature to the rails_before_7_2 annotations. Expect generic<T>. Released Solargraph 0.57.0 to 0.61.0 union it with the YARD self, so they are skipped. On master, Rails 7.2 and 8.0 need the collection revision bump that follows #1106 merging. Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]> Claude-Session: https://claude.ai/code/session_01SEntZKsZwQHhzqcwG7MTqn * Annotate Resources#new for every Rails version ruby/gem_rbs_collection#1106 may not merge soon, so on Rails 7.2 and later castwide/solargraph master still reports undefined for Mapper::Resources#new. Move its generic annotation out of rails_before_7_2 into the unscoped annotations, with a note to remove it once #1106 is released and the collection revision is bumped. Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]> Claude-Session: https://claude.ai/code/session_01SEntZKsZwQHhzqcwG7MTqn * Stop skipping Mapper#new on Solargraph 0.60 and 0.61 With the annotation applied for every Rails version, 0.60.4 and 0.61.0 infer generic<T> on Rails 7.2 and 8.0 too, and the spec fails on a skip that no longer holds. Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]> Claude-Session: https://claude.ai/code/session_01SEntZKsZwQHhzqcwG7MTqn --------- Co-authored-by: Claude Opus 5.5 (1M context) <[email protected]>

ksss

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github-actions · 2026-10-22T04:30:33Z

Thanks for your review, @ksss!

@apiology, @ksss This PR is ready to be merged.
Just comment /merge to merge this PR.

apiology and others added 5 commits October 19, 2026 12:48

apiology changed the title ~~actionpack: type the routing Mapper DSL return values~~ actionpack: type the routing Mapper DSL Oct 19, 2026

apiology marked this pull request as ready for review October 19, 2026 18:31

This was referenced Oct 20, 2026

Type routing Resources#new as the block's value iftheshoefritz/solargraph-rails#251

Merged

Expect routing new to return the block value iftheshoefritz/solargraph-rails#248

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ksss reviewed Oct 22, 2026

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actionpack: type the routing Mapper DSL - #1106

actionpack: type the routing Mapper DSL#1106
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