1 files changed, 76 insertions, 0 deletions
diff --git a/src/pkg/io/io_test.go b/src/pkg/io/io_test.go
index 4ad1e5951..4fcd85e69 100644
--- a/src/pkg/io/io_test.go
+++ b/src/pkg/io/io_test.go
@@ -7,6 +7,8 @@ package io_test
 import (
 	"bytes"
 	. "io"
+	"os"
+	"strings"
 	"testing"
 )
 
@@ -78,3 +80,77 @@ func TestCopynWriteTo(t *testing.T) {
 		t.Errorf("Copyn did not work properly")
 	}
 }
+
+type noReadFrom struct {
+	w Writer
+}
+
+func (w *noReadFrom) Write(p []byte) (n int, err os.Error) {
+	return w.w.Write(p)
+}
+
+func TestCopynEOF(t *testing.T) {
+	// Test that EOF behavior is the same regardless of whether
+	// argument to Copyn has ReadFrom.
+
+	b := new(bytes.Buffer)
+
+	n, err := Copyn(&noReadFrom{b}, strings.NewReader("foo"), 3)
+	if n != 3 || err != nil {
+		t.Errorf("Copyn(noReadFrom, foo, 3) = %d, %v; want 3, nil", n, err)
+	}
+
+	n, err = Copyn(&noReadFrom{b}, strings.NewReader("foo"), 4)
+	if n != 3 || err != os.EOF {
+		t.Errorf("Copyn(noReadFrom, foo, 4) = %d, %v; want 3, EOF", n, err)
+	}
+
+	n, err = Copyn(b, strings.NewReader("foo"), 3) // b has read from
+	if n != 3 || err != nil {
+		t.Errorf("Copyn(bytes.Buffer, foo, 3) = %d, %v; want 3, nil", n, err)
+	}
+
+	n, err = Copyn(b, strings.NewReader("foo"), 4) // b has read from
+	if n != 3 || err != os.EOF {
+		t.Errorf("Copyn(bytes.Buffer, foo, 4) = %d, %v; want 3, EOF", n, err)
+	}
+}
+
+func TestReadAtLeast(t *testing.T) {
+	var rb bytes.Buffer
+	rb.Write([]byte("0123"))
+	buf := make([]byte, 2)
+	n, err := ReadAtLeast(&rb, buf, 2)
+	if err != nil {
+		t.Error(err)
+	}
+	n, err = ReadAtLeast(&rb, buf, 4)
+	if err != ErrShortBuffer {
+		t.Errorf("expected ErrShortBuffer got %v", err)
+	}
+	if n != 0 {
+		t.Errorf("expected to have read 0 bytes, got %v", n)
+	}
+	n, err = ReadAtLeast(&rb, buf, 1)
+	if err != nil {
+		t.Error(err)
+	}
+	if n != 2 {
+		t.Errorf("expected to have read 2 bytes, got %v", n)
+	}
+	n, err = ReadAtLeast(&rb, buf, 2)
+	if err != os.EOF {
+		t.Errorf("expected EOF, got %v", err)
+	}
+	if n != 0 {
+		t.Errorf("expected to have read 0 bytes, got %v", n)
+	}
+	rb.Write([]byte("4"))
+	n, err = ReadAtLeast(&rb, buf, 2)
+	if err != ErrUnexpectedEOF {
+		t.Errorf("expected ErrUnexpectedEOF, got %v", err)
+	}
+	if n != 1 {
+		t.Errorf("expected to have read 1 bytes, got %v", n)
+	}
+}