1 files changed, 122 insertions, 0 deletions
diff --git a/Library/Homebrew/test/compiler_selector_spec.rb b/Library/Homebrew/test/compiler_selector_spec.rb
new file mode 100644
index 000000000..0f6f6b5f2
--- /dev/null
+++ b/Library/Homebrew/test/compiler_selector_spec.rb
@@ -0,0 +1,122 @@
+require "compilers"
+require "software_spec"
+
+describe CompilerSelector do
+  subject { described_class.new(software_spec, versions, compilers) }
+  let(:compilers) { [:clang, :gcc, :llvm, :gnu] }
+  let(:software_spec) { SoftwareSpec.new }
+  let(:cc) { :clang }
+  let(:versions) do
+    double(
+      gcc_4_0_build_version: Version::NULL,
+      gcc_build_version: Version.create("5666"),
+      llvm_build_version: Version::NULL,
+      clang_build_version: Version.create("425"),
+    )
+  end
+
+  before(:each) do
+    allow(versions).to receive(:non_apple_gcc_version) do |name|
+      case name
+      when "gcc-4.8" then Version.create("4.8.1")
+      when "gcc-4.7" then Version.create("4.7.1")
+      else Version::NULL
+      end
+    end
+  end
+
+  describe "#compiler" do
+    it "raises an error if no matching compiler can be found" do
+      software_spec.fails_with(:clang)
+      software_spec.fails_with(:llvm)
+      software_spec.fails_with(:gcc)
+      software_spec.fails_with(gcc: "4.8")
+      software_spec.fails_with(gcc: "4.7")
+
+      expect { subject.compiler }.to raise_error(CompilerSelectionError)
+    end
+
+    it "defaults to cc" do
+      expect(subject.compiler).to eq(cc)
+    end
+
+    it "returns gcc if it fails with clang" do
+      software_spec.fails_with(:clang)
+      expect(subject.compiler).to eq(:gcc)
+    end
+
+    it "returns clang if it fails with llvm" do
+      software_spec.fails_with(:llvm)
+      expect(subject.compiler).to eq(:clang)
+    end
+
+    it "returns clang if it fails with gcc" do
+      software_spec.fails_with(:gcc)
+      expect(subject.compiler).to eq(:clang)
+    end
+
+    it "returns clang if it fails with non-Apple gcc" do
+      software_spec.fails_with(gcc: "4.8")
+      expect(subject.compiler).to eq(:clang)
+    end
+
+    it "still returns gcc-4.8 if it fails with gcc without a specific version" do
+      software_spec.fails_with(:clang)
+      software_spec.fails_with(:gcc)
+      expect(subject.compiler).to eq("gcc-4.8")
+    end
+
+    it "returns gcc if it fails with clang and llvm" do
+      software_spec.fails_with(:clang)
+      software_spec.fails_with(:llvm)
+      expect(subject.compiler).to eq(:gcc)
+    end
+
+    it "returns clang if it fails with gcc and llvm" do
+      software_spec.fails_with(:gcc)
+      software_spec.fails_with(:llvm)
+      expect(subject.compiler).to eq(:clang)
+    end
+
+    example "returns gcc if it fails with a specific gcc version" do
+      software_spec.fails_with(:clang)
+      software_spec.fails_with(gcc: "4.8")
+      expect(subject.compiler).to eq(:gcc)
+    end
+
+    example "returns a lower version of gcc if it fails with the highest version" do
+      software_spec.fails_with(:clang)
+      software_spec.fails_with(:gcc)
+      software_spec.fails_with(:llvm)
+      software_spec.fails_with(gcc: "4.8")
+      expect(subject.compiler).to eq("gcc-4.7")
+    end
+
+    it "prefers gcc" do
+      software_spec.fails_with(:clang)
+      software_spec.fails_with(:gcc)
+      expect(subject.compiler).to eq("gcc-4.8")
+    end
+
+    it "raises an error when gcc is missing" do
+      allow(versions).to receive(:gcc_build_version).and_return(Version::NULL)
+
+      software_spec.fails_with(:clang)
+      software_spec.fails_with(:llvm)
+      software_spec.fails_with(gcc: "4.8")
+      software_spec.fails_with(gcc: "4.7")
+
+      expect { subject.compiler }.to raise_error(CompilerSelectionError)
+    end
+
+    it "raises an error when llvm and gcc are missing" do
+      allow(versions).to receive(:gcc_build_version).and_return(Version::NULL)
+
+      software_spec.fails_with(:clang)
+      software_spec.fails_with(gcc: "4.8")
+      software_spec.fails_with(gcc: "4.7")
+
+      expect { subject.compiler }.to raise_error(CompilerSelectionError)
+    end
+  end
+end