1 files changed, 194 insertions, 0 deletions
diff --git a/spec/ruby/core/kernel/open_spec.rb b/spec/ruby/core/kernel/open_spec.rb
new file mode 100644
index 0000000000..b967d5044b
--- /dev/null
+++ b/spec/ruby/core/kernel/open_spec.rb
@@ -0,0 +1,194 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+describe "Kernel#open" do
+  before :each do
+    @name = tmp("kernel_open.txt")
+    @content = "This is a test"
+    touch(@name) { |f| f.write @content }
+    @file = nil
+  end
+
+  after :each do
+    @file.close if @file
+    rm_r @name
+  end
+
+  it "is a private method" do
+    Kernel.should have_private_instance_method(:open)
+  end
+
+  it "opens a file when given a valid filename" do
+    @file = open(@name)
+    @file.should be_kind_of(File)
+  end
+
+  it "opens a file when called with a block" do
+    open(@name, "r") { |f| f.gets }.should == @content
+  end
+
+  ruby_version_is ""..."4.0" do
+    platform_is_not :windows, :wasi do
+      it "opens an io when path starts with a pipe" do
+        suppress_warning do # https://bugs.ruby-lang.org/issues/19630
+          @io = open("|date")
+        end
+        begin
+          @io.should be_kind_of(IO)
+          @io.read
+        ensure
+          @io.close
+        end
+      end
+
+      it "opens an io when called with a block" do
+        suppress_warning do # https://bugs.ruby-lang.org/issues/19630
+          @output = open("|date") { |f| f.read }
+        end
+        @output.should_not == ''
+      end
+
+      it "opens an io for writing" do
+        suppress_warning do # https://bugs.ruby-lang.org/issues/19630
+          -> {
+            bytes = open("|cat", "w") { |io| io.write(".") }
+            bytes.should == 1
+          }.should output_to_fd(".")
+        end
+      end
+    end
+
+    platform_is :windows do
+      it "opens an io when path starts with a pipe" do
+        suppress_warning do # https://bugs.ruby-lang.org/issues/19630
+          @io = open("|date /t")
+        end
+        begin
+          @io.should be_kind_of(IO)
+          @io.read
+        ensure
+          @io.close
+        end
+      end
+
+      it "opens an io when called with a block" do
+        suppress_warning do # https://bugs.ruby-lang.org/issues/19630
+          @output = open("|date /t") { |f| f.read }
+        end
+        @output.should_not == ''
+      end
+    end
+
+    ruby_version_is "3.3" do
+      # https://bugs.ruby-lang.org/issues/19630
+      it "warns about deprecation given a path with a pipe" do
+        cmd = "|echo ok"
+        -> {
+          open(cmd) { |f| f.read }
+        }.should complain(/Kernel#open with a leading '\|'/)
+      end
+    end
+  end
+
+  it "raises an ArgumentError if not passed one argument" do
+    -> { open }.should raise_error(ArgumentError)
+  end
+
+  it "accepts options as keyword arguments" do
+    @file = open(@name, "r", 0666, flags: File::CREAT)
+    @file.should be_kind_of(File)
+
+    -> {
+      open(@name, "r", 0666, {flags: File::CREAT})
+    }.should raise_error(ArgumentError, "wrong number of arguments (given 4, expected 1..3)")
+  end
+
+  describe "when given an object that responds to to_open" do
+    before :each do
+      ScratchPad.clear
+    end
+
+    it "calls #to_path to convert the argument to a String before calling #to_str" do
+      obj = mock("open to_path")
+      obj.should_receive(:to_path).at_least(1).times.and_return(@name)
+      obj.should_not_receive(:to_str)
+
+      open(obj, "r") { |f| f.gets }.should == @content
+    end
+
+    it "calls #to_str to convert the argument to a String" do
+      obj = mock("open to_str")
+      obj.should_receive(:to_str).at_least(1).times.and_return(@name)
+
+      open(obj, "r") { |f| f.gets }.should == @content
+    end
+
+    it "calls #to_open on argument" do
+      obj = mock('fileish')
+      @file = File.open(@name)
+      obj.should_receive(:to_open).and_return(@file)
+      @file = open(obj)
+      @file.should be_kind_of(File)
+    end
+
+    it "returns the value from #to_open" do
+      obj = mock('to_open')
+      obj.should_receive(:to_open).and_return(:value)
+
+      open(obj).should == :value
+    end
+
+    it "passes its arguments onto #to_open" do
+      obj = mock('to_open')
+      obj.should_receive(:to_open).with(1, 2, 3)
+      open(obj, 1, 2, 3)
+    end
+
+    it "passes keyword arguments onto #to_open as keyword arguments if to_open accepts them" do
+      obj = Object.new
+      def obj.to_open(*args, **kw)
+        ScratchPad << {args: args, kw: kw}
+      end
+
+      ScratchPad.record []
+      open(obj, 1, 2, 3, a: "b")
+      ScratchPad.recorded.should == [args: [1, 2, 3], kw: {a: "b"}]
+    end
+
+    it "passes the return value from #to_open to a block" do
+      obj = mock('to_open')
+      obj.should_receive(:to_open).and_return(:value)
+
+      open(obj) do |mock|
+        ScratchPad.record(mock)
+      end
+
+      ScratchPad.recorded.should == :value
+    end
+  end
+
+  it "raises a TypeError if passed a non-String that does not respond to #to_open" do
+    obj = mock('non-fileish')
+    -> { open(obj) }.should raise_error(TypeError)
+    -> { open(nil) }.should raise_error(TypeError)
+    -> { open(7)   }.should raise_error(TypeError)
+  end
+
+  it "accepts nil for mode and permission" do
+    open(@name, nil, nil) { |f| f.gets }.should == @content
+  end
+
+  it "is not redefined by open-uri" do
+    code = <<~RUBY
+      before = Kernel.instance_method(:open)
+      require 'open-uri'
+      after = Kernel.instance_method(:open)
+      p before == after
+    RUBY
+    ruby_exe(code, args: "2>&1").should == "true\n"
+  end
+end
+
+describe "Kernel.open" do
+  it "needs to be reviewed for spec completeness"
+end