1 files changed, 103 insertions, 0 deletions
diff --git a/spec/ruby/library/stringio/putc_spec.rb b/spec/ruby/library/stringio/putc_spec.rb
new file mode 100644
index 0000000000..742f8623eb
--- /dev/null
+++ b/spec/ruby/library/stringio/putc_spec.rb
@@ -0,0 +1,103 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+describe "StringIO#putc when passed [String]" do
+  before :each do
+    @io = StringIO.new(+'example')
+  end
+
+  it "overwrites the character at the current position" do
+    @io.putc("t")
+    @io.string.should == "txample"
+
+    @io.pos = 3
+    @io.putc("t")
+    @io.string.should == "txatple"
+  end
+
+  it "only writes the first character from the passed String" do
+    @io.putc("test")
+    @io.string.should == "txample"
+  end
+
+  it "returns the passed String" do
+    str = "test"
+    @io.putc(str).should.equal?(str)
+  end
+
+  it "correctly updates the current position" do
+    @io.putc("t")
+    @io.pos.should == 1
+
+    @io.putc("test")
+    @io.pos.should == 2
+
+    @io.putc("t")
+    @io.pos.should == 3
+  end
+
+  it "handles concurrent writes correctly" do
+    @io = StringIO.new
+    n = 8
+    go = false
+    threads = n.times.map { |i|
+      Thread.new {
+        Thread.pass until go
+        @io.putc i.to_s
+      }
+    }
+    go = true
+    threads.each(&:join)
+    @io.string.size.should == n
+  end
+end
+
+describe "StringIO#putc when passed [Object]" do
+  before :each do
+    @io = StringIO.new(+'example')
+  end
+
+  it "it writes the passed Integer % 256 to self" do
+    @io.putc(333) # 333 % 256 == ?M
+    @io.string.should == "Mxample"
+
+    @io.putc(-450) # -450 % 256 == ?>
+    @io.string.should == "M>ample"
+  end
+
+  it "pads self with \\000 when the current position is after the end" do
+    @io.pos = 10
+    @io.putc(?A)
+    @io.string.should == "example\000\000\000A"
+  end
+
+  it "tries to convert the passed argument to an Integer using #to_int" do
+    obj = mock('to_int')
+    obj.should_receive(:to_int).and_return(116)
+    @io.putc(obj)
+    @io.string.should == "txample"
+  end
+
+  it "raises a TypeError when the passed argument can't be coerced to Integer" do
+    -> { @io.putc(Object.new) }.should.raise(TypeError)
+  end
+end
+
+describe "StringIO#putc when in append mode" do
+  it "appends to the end of self" do
+    io = StringIO.new(+"test", "a")
+    io.putc(?t)
+    io.string.should == "testt"
+  end
+end
+
+describe "StringIO#putc when self is not writable" do
+  it "raises an IOError" do
+    io = StringIO.new(+"test", "r")
+    -> { io.putc(?a) }.should.raise(IOError)
+
+    io = StringIO.new(+"test")
+    io.close_write
+    -> { io.putc("t") }.should.raise(IOError)
+  end
+end