1 files changed, 29 insertions, 14 deletions
diff --git a/spec/ruby/core/kernel/system_spec.rb b/spec/ruby/core/kernel/system_spec.rb
index 696e6ae3d7..b24956104a 100644
--- a/spec/ruby/core/kernel/system_spec.rb
+++ b/spec/ruby/core/kernel/system_spec.rb
@@ -5,14 +5,14 @@ describe :kernel_system, shared: true do
   it "executes the specified command in a subprocess" do
     -> { @object.system("echo a") }.should output_to_fd("a\n")
 
-    $?.should be_an_instance_of Process::Status
+    $?.should.instance_of? Process::Status
     $?.should.success?
   end
 
   it "returns true when the command exits with a zero exit status" do
     @object.system(ruby_cmd('exit 0')).should == true
 
-    $?.should be_an_instance_of Process::Status
+    $?.should.instance_of? Process::Status
     $?.should.success?
     $?.exitstatus.should == 0
   end
@@ -20,26 +20,24 @@ describe :kernel_system, shared: true do
   it "returns false when the command exits with a non-zero exit status" do
     @object.system(ruby_cmd('exit 1')).should == false
 
-    $?.should be_an_instance_of Process::Status
+    $?.should.instance_of? Process::Status
     $?.should_not.success?
     $?.exitstatus.should == 1
   end
 
-  ruby_version_is "2.6" do
-    it "raises RuntimeError when `exception: true` is given and the command exits with a non-zero exit status" do
-      -> { @object.system(ruby_cmd('exit 1'), exception: true) }.should raise_error(RuntimeError)
-    end
+  it "raises RuntimeError when `exception: true` is given and the command exits with a non-zero exit status" do
+    -> { @object.system(ruby_cmd('exit 1'), exception: true) }.should.raise(RuntimeError)
+  end
 
-    it "raises Errno::ENOENT when `exception: true` is given and the specified command does not exist" do
-      -> { @object.system('feature_14386', exception: true) }.should raise_error(Errno::ENOENT)
-    end
+  it "raises Errno::ENOENT when `exception: true` is given and the specified command does not exist" do
+    -> { @object.system('feature_14386', exception: true) }.should.raise(Errno::ENOENT)
   end
 
   it "returns nil when command execution fails" do
-    @object.system("sad").should be_nil
+    @object.system("sad").should == nil
 
-    $?.should be_an_instance_of Process::Status
-    $?.pid.should be_kind_of(Integer)
+    $?.should.instance_of? Process::Status
+    $?.pid.should.is_a?(Integer)
     $?.should_not.success?
   end
 
@@ -66,6 +64,23 @@ describe :kernel_system, shared: true do
     end
   end
 
+  platform_is_not :windows do
+    before :each do
+      require 'tmpdir'
+      @shell_command = File.join(Dir.mktmpdir, "noshebang.cmd")
+      File.write(@shell_command, %[echo "$PATH"\n], perm: 0o700)
+    end
+
+    after :each do
+      File.unlink(@shell_command)
+      Dir.rmdir(File.dirname(@shell_command))
+    end
+
+    it "executes with `sh` if the command is executable but not binary and there is no shebang" do
+      -> { @object.system(@shell_command) }.should output_to_fd(ENV['PATH'] + "\n")
+    end
+  end
+
   before :each do
     ENV['TEST_SH_EXPANSION'] = 'foo'
     @shell_var = '$TEST_SH_EXPANSION'
@@ -106,7 +121,7 @@ end
 
 describe "Kernel#system" do
   it "is a private method" do
-    Kernel.should have_private_instance_method(:system)
+    Kernel.private_instance_methods(false).should.include?(:system)
   end
 
   it_behaves_like :kernel_system, :system, KernelSpecs::Method.new