Remove API placeholders in FormulaStruct and CaskStruct

[Rylan12]

When generating the API, we replace HOMEBREW_PREFIX and Dir.home with placeholder values, but we don't actually replace the placeholders with the real values when loading from FormulaStruct (or CaskStruct). This PR adds the replacement logic to the APIHashable module so it's included by default anywhere the module is used.

[Copilot]

Pull request overview

This PR aims to ensure API path placeholders (e.g., $HOMEBREW_PREFIX, /$HOME) are replaced with real local values when API data is loaded into FormulaStruct/CaskStruct, by centralizing placeholder-removal logic in APIHashable.

Changes:

• Add APIHashable#deep_remove_placeholders to recursively replace API placeholders in hashes/arrays/strings.
• Call placeholder removal during Homebrew::API::FormulaStruct.from_hash and Homebrew::API::CaskStruct.from_hash.
• Add a temporary-looking filter in generate-formula-api.rb that limits generation to redis.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 4 comments.

File	Description
Library/Homebrew/dev-cmd/generate-formula-api.rb	Adds a per-formula filter (currently hardcoded to only generate redis).
Library/Homebrew/api_hashable.rb	Introduces recursive placeholder removal helper in APIHashable.
Library/Homebrew/api/formula_struct.rb	Applies placeholder removal when constructing FormulaStruct from a hash.
Library/Homebrew/api/cask_struct.rb	Applies placeholder removal when constructing CaskStruct from a hash.

Comments suppressed due to low confidence (2)

Library/Homebrew/api/formula_struct.rb:16

• This change adds new behavior (placeholder replacement) to FormulaStruct.from_hash, but there are no tests covering placeholder removal when constructing/deserialize-ing a Homebrew::API::FormulaStruct. Adding a spec that passes a hash containing $HOMEBREW_PREFIX//$HOME/$HOMEBREW_CELLAR and asserts the resulting struct contains real paths would help prevent regressions.

      def self.from_hash(formula_hash)
        formula_hash = ::Formula.deep_remove_placeholders(formula_hash)
        formula_hash = formula_hash.transform_keys(&:to_sym)
                                   .slice(*decorator.all_props)
                                   .compact_blank
        new(**formula_hash)

Library/Homebrew/api/cask_struct.rb:15

• This change adds new behavior (placeholder replacement) to CaskStruct.from_hash, but the existing api/cask_struct_spec.rb coverage for ::from_hash doesn’t assert placeholder removal. Add a test case that includes $HOMEBREW_PREFIX//$HOME/$HOMEBREW_CELLAR in raw_caveats or raw_artifacts and verifies the struct (or #caveats/#artifacts) resolves them correctly.

      def self.from_hash(cask_hash, ignore_types: false)
        return super(cask_hash) if ignore_types

        cask_hash = ::Cask::Cask.deep_remove_placeholders(cask_hash)
        cask_hash = cask_hash.transform_keys(&:to_sym)
                             .slice(*decorator.all_props)
                             .compact_blank
        new(**cask_hash)

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[MikeMcQuaid]

Thanks!