Hardware: add helper to determine if an executable can be run

1 files changed, 47 insertions, 0 deletions

diff --git a/Library/Homebrew/test/hardware_spec.rb b/Library/Homebrew/test/hardware_spec.rb
index c5f8daf4e..de8d77e68 100644
--- a/Library/Homebrew/test/hardware_spec.rb
+++ b/Library/Homebrew/test/hardware_spec.rb
@@ -36,5 +36,52 @@ module Hardware
         ).to include(described_class.family)
       end
     end
+
+    describe "::can_run?" do
+      it "reports that Intel machines can run Intel executables" do
+        allow(Hardware::CPU).to receive(:type).and_return :intel
+        allow(Hardware::CPU).to receive(:bits).and_return 64
+        expect(Hardware::CPU.can_run?(:i386)).to be true
+        expect(Hardware::CPU.can_run?(:x86_64)).to be true
+      end
+
+      it "reports that PowerPC machines can run PowerPC executables" do
+        allow(Hardware::CPU).to receive(:type).and_return :ppc
+        allow(Hardware::CPU).to receive(:bits).and_return 64
+        expect(Hardware::CPU.can_run?(:ppc)).to be true
+        expect(Hardware::CPU.can_run?(:ppc64)).to be true
+      end
+
+      it "reports that 32-bit Intel machines can't run x86_64 executables" do
+        allow(Hardware::CPU).to receive(:type).and_return :intel
+        allow(Hardware::CPU).to receive(:bits).and_return 32
+        expect(Hardware::CPU.can_run?(:x86_64)).to be false
+      end
+
+      it "reports that 32-bit PowerPC machines can't run ppc64 executables" do
+        allow(Hardware::CPU).to receive(:type).and_return :ppc
+        allow(Hardware::CPU).to receive(:bits).and_return 32
+        expect(Hardware::CPU.can_run?(:ppc64)).to be false
+      end
+
+      it "identifies that Intel and PowerPC machines can't run each others' executables" do
+        allow(Hardware::CPU).to receive(:type).and_return :ppc
+        expect(Hardware::CPU.can_run?(:i386)).to be false
+        expect(Hardware::CPU.can_run?(:x86_64)).to be false
+
+        allow(Hardware::CPU).to receive(:type).and_return :intel
+        expect(Hardware::CPU.can_run?(:ppc)).to be false
+        expect(Hardware::CPU.can_run?(:ppc64)).to be false
+      end
+
+      it "returns false for unknown CPU types" do
+        allow(Hardware::CPU).to receive(:type).and_return :dunno
+        expect(Hardware::CPU.can_run?(:i386)).to be false
+      end
+
+      it "returns false for unknown arches" do
+        expect(Hardware::CPU.can_run?(:blah)).to be false
+      end
+    end
   end
 end