initial commits

copyline.go

@@ -22,9 +22,9 @@ import (
 // Note that ‘n64’ represents how many bytes were written, not read.
 func CopyLine(writer io.Writer, reader io.Reader) (n64 int64, err error) {
 
-	for {
-		var eof bool
+	var eof bool
 
+	for {
 		var r0 rune
 		var size0 int
 		{
@@ -113,5 +113,9 @@ func CopyLine(writer io.Writer, reader io.Reader) (n64 int64, err error) {
 		break
 	}
 
+	if eof && n64 <= 0 {
+		return n64, io.EOF
+	}
+
 	return n64, nil
 }

copyline_test.go

@@ -191,3 +191,41 @@ func TestCopyLine(t *testing.T) {
 		}
 	}
 }
+
+func TestCopyLine_empty(t *testing.T) {
+
+	var reader io.Reader = strings.NewReader("")
+
+	var actualStorage strings.Builder
+
+	actualN, err := netln.CopyLine(&actualStorage, reader)
+	if nil == err {
+		t.Error("Expected an error but did not actually get one.")
+		t.Logf("ERROR: (%T) %q", err, err)
+		return
+	}
+
+	{
+		var expected error = io.EOF
+		var actual   error = err
+
+		if expected != actual {
+			t.Errorf("The actual error was not what was expeceted.")
+			t.Logf("EXPECTED-ERROR: (%T) %q", expected, expected)
+			t.Logf("ACTUAL-ERROR:   (%T) %q", actual,   actual)
+			return
+		}
+	}
+
+	{
+		var expected int64 = 0
+		var actual   int64 = actualN
+
+		if expected != actual {
+			t.Error("The actual number of bytes written is not what was expected.")
+			t.Logf("EXPECTED: %d bytes", expected)
+			t.Logf("ACTUAL:   %d bytes", actual)
+			return
+		}
+	}
+}