1 files changed, 96 insertions, 0 deletions
diff --git a/spec/ruby/core/io/foreach_spec.rb b/spec/ruby/core/io/foreach_spec.rb
new file mode 100644
index 0000000000..015988f9fb
--- /dev/null
+++ b/spec/ruby/core/io/foreach_spec.rb
@@ -0,0 +1,96 @@
+# -*- encoding: utf-8 -*-
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+require_relative 'shared/readlines'
+
+describe "IO.foreach" do
+  before :each do
+    @name = fixture __FILE__, "lines.txt"
+    @count = 0
+    ScratchPad.record []
+  end
+
+  it "updates $. with each yield" do
+    IO.foreach(@name) { $..should == @count += 1 }
+  end
+
+  ruby_version_is ""..."4.0" do
+    describe "when the filename starts with |" do
+      it "gets data from the standard out of the subprocess" do
+        cmd = "|sh -c 'echo hello;echo line2'"
+        platform_is :windows do
+          cmd = "|cmd.exe /C echo hello&echo line2"
+        end
+
+        suppress_warning do # https://bugs.ruby-lang.org/issues/19630
+          IO.foreach(cmd) { |l| ScratchPad << l }
+        end
+        ScratchPad.recorded.should == ["hello\n", "line2\n"]
+      end
+
+      platform_is_not :windows do
+        it "gets data from a fork when passed -" do
+          parent_pid = $$
+
+          suppress_warning do # https://bugs.ruby-lang.org/issues/19630
+            IO.foreach("|-") { |l| ScratchPad << l }
+          end
+
+          if $$ == parent_pid
+            ScratchPad.recorded.should == ["hello\n", "from a fork\n"]
+          else # child
+            puts "hello"
+            puts "from a fork"
+            exit!
+          end
+        end
+      end
+    end
+
+    # https://bugs.ruby-lang.org/issues/19630
+    it "warns about deprecation given a path with a pipe" do
+      cmd = "|echo ok"
+      -> {
+        IO.foreach(cmd).to_a
+      }.should complain(/IO process creation with a leading '\|'/)
+    end
+  end
+end
+
+describe "IO.foreach" do
+  before :each do
+    @external = Encoding.default_external
+    Encoding.default_external = Encoding::UTF_8
+
+    @name = fixture __FILE__, "lines.txt"
+    ScratchPad.record []
+  end
+
+  after :each do
+    Encoding.default_external = @external
+  end
+
+  it "sets $_ to nil" do
+    $_ = "test"
+    IO.foreach(@name) { }
+    $_.should == nil
+  end
+
+  describe "when no block is given" do
+    it "returns an Enumerator" do
+      IO.foreach(@name).should.instance_of?(Enumerator)
+      IO.foreach(@name).to_a.should == IOSpecs.lines
+    end
+
+    describe "returned Enumerator" do
+      describe "size" do
+        it "should return nil" do
+          IO.foreach(@name).size.should == nil
+        end
+      end
+    end
+  end
+
+  it_behaves_like :io_readlines, :foreach, IOSpecs.collector
+  it_behaves_like :io_readlines_options_19, :foreach, IOSpecs.collector
+end