Set --formula by default on linux

Library/Homebrew/cli/args.rb

@@ -96,6 +96,7 @@ module Homebrew
       end
 
       def only_formula_or_cask
+        return :formula if OS.linux? && !Homebrew::EnvConfig.developer?
         return :formula if formula? && !cask?
         return :cask if cask? && !formula?
       end

Library/Homebrew/test/cli/named_args_spec.rb

@@ -118,6 +118,12 @@ describe Homebrew::CLI::NamedArgs do
       expect { described_class.new("foo").to_formulae_and_casks }.to raise_error(FormulaOrCaskUnavailableError)
     end
 
+    it "raises an error when formula is absent and cask is available on linux", :needs_linux do
+      stub_cask_loader foo_cask
+
+      expect { described_class.new("foo").to_formulae_and_casks }.to raise_error(FormulaOrCaskUnavailableError)
+    end
+
     it "returns formula when formula is present and cask is unreadable" do
       stub_formula_loader foo
       setup_unredable_cask "foo"
@@ -126,7 +132,7 @@ describe Homebrew::CLI::NamedArgs do
       expect { described_class.new("foo").to_formulae_and_casks }.to output(/Failed to load cask: foo/).to_stderr
     end
 
-    it "returns cask when formula is unreadable and cask is present" do
+    it "returns cask when formula is unreadable and cask is present", :dev_on_linux do
       setup_unredable_formula "foo"
       stub_cask_loader foo_cask
 
@@ -156,7 +162,7 @@ describe Homebrew::CLI::NamedArgs do
   end
 
   describe "#to_resolved_formulae_to_casks" do
-    it "returns resolved formulae, as well as casks" do
+    it "returns resolved formulae, as well as casks", :dev_on_linux do
       allow(Formulary).to receive(:resolve).and_call_original
       allow(Formulary).to receive(:resolve).with("foo", any_args).and_return foo
       stub_cask_loader baz, call_original: true
@@ -245,7 +251,7 @@ describe Homebrew::CLI::NamedArgs do
       (HOMEBREW_CELLAR/"foo/1.0").mkpath
     end
 
-    it "returns kegs, as well as casks" do
+    it "returns kegs, as well as casks", :dev_on_linux do
       stub_cask_loader baz, call_original: true
 
       kegs, casks = described_class.new("foo", "baz").to_kegs_to_casks
@@ -279,7 +285,7 @@ describe Homebrew::CLI::NamedArgs do
       allow(Cask::CaskLoader).to receive(:path).and_call_original
     end
 
-    it "returns taps, cask formula and existing paths" do
+    it "returns taps, cask formula and existing paths", :dev_on_linux do
       expect(Formulary).to receive(:path).with("foo").and_return(formula_path)
       expect(Cask::CaskLoader).to receive(:path).with("baz").and_return(cask_path)
 
@@ -287,7 +293,7 @@ describe Homebrew::CLI::NamedArgs do
         .to eq [Tap.fetch("homebrew/core").path, formula_path, cask_path, existing_path]
     end
 
-    it "returns both cask and formula paths if they exist" do
+    it "returns both cask and formula paths if they exist", :dev_on_linux do
       expect(Formulary).to receive(:path).with("foo").and_return(formula_path)
       expect(Cask::CaskLoader).to receive(:path).with("baz").and_return(cask_path)
 
@@ -305,6 +311,12 @@ describe Homebrew::CLI::NamedArgs do
 
       expect(described_class.new("foo", "baz").to_paths(only: :cask)).to eq [cask_path, Cask::CaskLoader.path("baz")]
     end
+
+    it "returns only formulae by default on linux", :needs_linux do
+      expect(Formulary).to receive(:path).with("foo").and_return(formula_path)
+
+      expect(described_class.new("foo", "baz").to_paths).to eq [formula_path, Formulary.path("baz")]
+    end
   end
 
   describe "#to_taps" do

Library/Homebrew/test/cmd/--cache_spec.rb

@@ -28,7 +28,7 @@ describe "brew --cache" do
       .and be_a_success
   end
 
-  it "prints the cache files for a given Formula and Cask", :integration_test do
+  it "prints the cache files for a given Formula and Cask", :integration_test, :dev_on_linux do
     expect { brew "--cache", testball, cask_path("local-caffeine") }
       .to output(
         %r{

Library/Homebrew/test/cmd/home_spec.rb

@@ -45,7 +45,7 @@ describe "brew home" do
       .and be_a_success
   end
 
-  it "opens the homepages for a given formula and Cask", :integration_test do
+  it "opens the homepages for a given formula and Cask", :integration_test, :dev_on_linux do
     setup_test_formula "testballhome"
 
     expect { brew "home", "testballhome", local_caffeine_path, "HOMEBREW_BROWSER" => "echo" }

Library/Homebrew/test/spec_helper.rb

@@ -180,6 +180,10 @@ RSpec.configure do |config|
     skip "Unzip is not installed." unless which("unzip")
   end
 
+  config.before(:each, :dev_on_linux) do
+    Allow(Homebrew::EnvConfig).to receive(:developer?).and_return(true) if OS.linux?
+  end
+
   config.around do |example|
     def find_files
       return [] unless File.exist?(TEST_TMPDIR)