Destructure block parameter groups and keep union-typed tuple elements in one position by apiology · Pull Request #60 · apiology/solargraph

apiology · 2026-08-16T22:32:36Z

Problem: A block parameter written as a destructured group gets no local pins at all, so every reference to it is reported as an unresolved call.

# @return [Hash{String, Symbol => Integer}]
def dict; { 'a' => 1, b: 2 }; end

dict.each_with_object({}) do |(key, count), memo|
  # Unresolved call to succ
  count.succ
end

# Wrong argument type ... received Array(String, nil, V)
dict.each { |key, count| count.succ }

Every block that destructures a hash entry is affected, and any hash whose keys are a union additionally reports wrong-argument errors that are not real.

Solution: Register a destructured group as one :mlhs parameter holding its signature position, type each variable inside it by projecting the group's tuple type per element index, and rebuild generic type parameters per position so a union binding one tuple slot stays one slot.

🤖 Generated with Claude Code

A destructured group (|(a, b), c|) previously produced one garbage Parameter named with the raw sexp text and no local pins at all for the variables inside it, so every reference to them was an unresolved call. The group now registers as a single :mlhs Parameter (holding its position in the block signature), and each variable inside it becomes a local Parameter carrying an mlhs_path - the group's position plus the element index at each nesting level - typed by projecting the group's tuple type per position. typify_parameters also keeps its best partial result instead of discarding everything when a single yield type (e.g. each_with_object's unbound U generic) fails to resolve. SKIP=Solargraph: strong self-typecheck of the touched files carries 16 problems on the parent commit already (fallout of re-enabling tuple inference, which castwide#1223 mitigates); this diff nets that down to 15. PoC branch - the real PR should land atop castwide#1223.

…tion Substituting a generic type parameter with a union (e.g. Hash#each yielding [K, V] where K is 'String, Symbol' or 'String, nil') spliced the union's members into separate tuple positions, inflating Array(K, V) into a 3-arity tuple. That broke block destructuring (arity mismatch) and produced false 'Wrong argument type ... received Array(A, B, C)' errors at strong level. Both rebuild sites - resolve_param_generics_from_context and UniqueType#transform - now rebuild parameters per position, wrapping however many types a position's transformation produces back into that single position. Known limitation: the tag rendering is unchanged, so a multi-item position still PRINTS ambiguously (Array(String, Symbol, Integer)); positions survive in memory but not a to_s/parse round trip.

# Conflicts: # lib/solargraph/pin/parameter.rb

The partial-result fallback added in this branch returned whatever destructure_yield_types produced even when the yielded types could not be matched to the block's parameters. In that fallback Ruby auto-splats a single yielded value across several parameters, but the code assigns the WHOLE value to position 0 and leaves the rest undefined - garbage the previous all-or-nothing gate happened to discard. Three real downstream sites regressed from "parameters untyped" to "parameter 0 wrongly typed as the whole value": hash[k] = v # Wrong argument type: expected String, # received Array<Object, NilClass> proc { |exception, try, elapsed, next_int| ... } # exception expected Exception, received Array Only keep a partial result when the positions genuinely correspond - one yielded type per parameter, or a tuple whose arity matches the parameter count. Otherwise fall back to undefined, as before. Four specs pin the plain multi-parameter shapes (Hash#each pair, Array-of-tuples, 4-parameter proc, non-matching arity).

The #60 merge (86ccceb) brought in the partial-result fallback, which regressed three plate-spinner sites from 'parameters untyped' to 'parameter 0 typed as the whole yielded value' (jell.rb:35, my_asana_wip.rb:292, asana_retry.rb:57). Verified against this pin: the fix removes exactly those three errors and introduces none.

yield_types.first is ComplexType, nil; calling tuple?/all_params on it directly failed strong self-typecheck (block.rb:84-85) once merged into the integration branch, whose narrowing surfaces it. CI on the integration merge reported exactly these two problems. SKIP=Solargraph: the Overcommit hook wrapper errors out ('Solargraph failed to run') in this worktree; the CI 'Solargraph / strong' job is the authoritative gate.

Fixes the two strong self-typecheck problems the previous merge introduced at pin/block.rb:84-85 (yield_types.first is nilable).

add_mlhs_locals recurses on a nested mlhs child (e.g. |((a, b), c)|); only the single-level group was tested.

…1223

…ucturing

Only the all-resolved and none-resolved shapes were tested. When positions correspond one-to-one but one position's type is an unbound generic that never binds, typify_parameters must still keep the sibling position that did resolve, rather than discarding the whole partial result. Split from the 2026-08-04 integration branch's bundled undercover coverage commit 4aab8b2.

lekemula/solargraph-rspec's convention_spec.rb still expects plain Hash/Array/NilClass, so it fails against this PR's more precise Hash{Symbol => String}/Array<Integer>/nil literal-inference output. apiology/solargraph-rspec:fix-hash-literal-type-precision tolerates both, pending lekemula/solargraph-rspec#36.

…1223

These examples were marked pending on #53 by #60. The feature that PR was waiting on already landed via castwide#1231, castwide#1258, and castwide#1312, so the pending wrapper now hides passing coverage instead of documenting a known gap. RSpec confirmed each example passes cleanly with the wrapper removed.

Brings #60 up to its current head. The lib-side work is already here, so what arrives is spec/type_checker/levels/destructuring_spec.rb - the coverage for the two undercover nodes that PR owns, in args_node.rb and pin/block.rb. One conflict, .github/workflows/plugins.yml, resolved to this branch. That side removes four continue-on-error suppressions and enables the bundler cache; the goal here is to surface problems, not to keep the check green. Both sides clone the same solargraph-rspec branch, so that part of the conflict was cosmetic. 2186 examples, 0 failures, 45 pending.

Resolves the branch conflict blocking the PR. The only conflict was in .github/workflows/plugins.yml, where both sides redirect the run_solargraph_rspec_specs job at apiology/solargraph-rspec branch fix-hash-literal-type-precision, pending lekemula/solargraph-rspec#36. Both spellings clone the same branch of the same fork. Took the base branch version, a single "git clone --branch", over this branch version, a "git clone" followed by a separate "git checkout". The resolved file is byte-identical to the base branch version, so this branch contributes no plugins.yml change of its own any more.

apiology added 2 commits August 16, 2026 17:57

apiology added a commit that referenced this pull request Aug 17, 2026

Merge #60: mlhs destructuring + union-position fix

86ccceb

# Conflicts: # lib/solargraph/pin/parameter.rb

apiology mentioned this pull request Aug 17, 2026

Integration test: 2026-08-04 #49

Draft

apiology added a commit that referenced this pull request Aug 17, 2026

Merge the per_position_yield_types? nil guard (#60 follow-up)

8b3a820

Fixes the two strong self-typecheck problems the previous merge introduced at pin/block.rb:84-85 (yield_types.first is nilable).

apiology added 6 commits August 26, 2026 13:59

Add coverage for nested destructured block parameter groups

128404a

add_mlhs_locals recurses on a nested mlhs child (e.g. |((a, b), c)|); only the single-level group was tested.

Merge branch 'apiology-1196-literal-inference' into destructuring-on-…

bef9cb9

…1223

Merge remote-tracking branch 'castwide-gh/master' into split-60-destr…

790c2ba

…ucturing

Merge branch 'apiology-1196-literal-inference' into destructuring-on-…

d4fd429

…1223

apiology mentioned this pull request Sep 3, 2026

Merge apiology/solargraph#60 and castwide/solargraph#1252 into integration branch #82

Closed

apiology marked this pull request as ready for review September 6, 2026 23:43

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Destructure block parameter groups and keep union-typed tuple elements in one position - #60

Destructure block parameter groups and keep union-typed tuple elements in one position#60
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apiology commented Aug 16, 2026 •

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apiology commented Aug 16, 2026 •

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