Only allow mapping with environment variable

Co-authored-by: Mike McQuaid <mike@mikemcquaid.com>

Library/Homebrew/formulary.rb

@@ -395,7 +395,11 @@ module Formulary
   )
     raise ArgumentError, "Formulae must have a ref!" unless ref
 
-    ref = @name_mappings[ref] if @name_mappings.present? && @name_mappings.key?(ref)
+    if ENV["HOMEBREW_BOTTLE_JSON"].present? &&
+       @formula_name_local_bottle_path_map.present? &&
+       @formula_name_local_bottle_path_map.key?(ref)
+      ref = @formula_name_local_bottle_path_map[ref]
+    end
 
     cache_key = "#{ref}-#{spec}-#{alias_path}-#{from}"
     if factory_cached? && cache[:formulary_factory] &&
@@ -413,18 +417,22 @@ module Formulary
     formula
   end
 
-  # Map a formula name to a bottle archive. This mapping will be used by {Formulary::factory}
-  # to allow formulae to be loaded automatically from their bottle archive without
-  # needing to exist in a tap or be passed as a complete filepath. For example,
-  # to map `foo` to the `hello` formula from its bottle archive:
-  # <pre>Formulary.map_name_to_bottle "foo", HOMEBREW_CACHE/"hello--2.10"
-  # Formulary.factory "foo" # returns the hello formula from the bottle archive
+  # Map a formula name to a local/fetched bottle archive. This mapping will be used by {Formulary::factory}
+  # to allow formulae to be loaded automatically from their local bottle archive without
+  # needing to exist in a tap or be passed as a complete path. For example,
+  # to map `hello` from its bottle archive:
+  # <pre>Formulary.map_formula_name_to_local_bottle_path "hello", HOMEBREW_CACHE/"hello--2.10"
+  # Formulary.factory "hello" # returns the hello formula from the local bottle archive
   # </pre>
-  # @param name the string to map.
-  # @param bottle a path pointing to the target bottle archive.
-  def self.map_name_to_bottle(name, bottle)
-    @name_mappings ||= {}
-    @name_mappings[name] = Pathname(bottle).realpath
+  # @param formula_name the formula name string to map.
+  # @param local_bottle_path a path pointing to the target bottle archive.
+  def self.map_formula_name_to_local_bottle_path(formula_name, local_bottle_path)
+    if ENV["HOMEBREW_BOTTLE_JSON"].blank?
+      raise UsageError, "HOMEBREW_BOTTLE_JSON not set but required for #{__method__}!"
+    end
+
+    @formula_name_local_bottle_path_map ||= {}
+    @formula_name_local_bottle_path_map[formula_name] = Pathname(local_bottle_path).realpath
   end
 
   # Return a {Formula} instance for the given rack.

Library/Homebrew/test/formulary_spec.rb

@@ -205,7 +205,7 @@ describe Formulary do
     end
   end
 
-  describe "::map_name_to_bottle" do
+  describe "::map_formula_name_to_local_bottle_path" do
     before do
       formula_path.dirname.mkpath
       formula_path.write formula_content
@@ -216,7 +216,13 @@ describe Formulary do
         described_class.factory("formula-to-map")
       }.to raise_error(FormulaUnavailableError)
 
-      described_class.map_name_to_bottle "formula-to-map", formula_path
+      ENV["HOMEBREW_BOTTLE_JSON"] = nil
+      expect {
+        described_class.map_formula_name_to_local_bottle_path "formula-to-map", formula_path
+      }.to raise_error(UsageError, /HOMEBREW_BOTTLE_JSON not set/)
+
+      ENV["HOMEBREW_BOTTLE_JSON"] = "1"
+      described_class.map_formula_name_to_local_bottle_path "formula-to-map", formula_path
 
       expect(described_class.factory("formula-to-map")).to be_kind_of(Formula)
     end