Improved message

test.go

@@ -12,6 +12,8 @@ import (
 // ErrPlain is the default error that is returned for functions in this package.
 var ErrPlain = errors.New("error")
 
+////////////////////////////////////////////////////////////////
+
 func fileline(i int) string {
 	_, file, line, ok := runtime.Caller(i)
 	if !ok {
@@ -28,42 +30,52 @@ func trace() string {
 	return "\r\t" + strings.Repeat(" ", len(fmt.Sprintf("%s:", trace2))) + "\r\t" + trace3
 }
 
+func message(empty string, msgs ...interface{}) string {
+	msg := fmt.Sprintln(msgs...)
+	if len(msg) == 0 {
+		msg = empty + "\n"
+	}
+	return msg
+}
+
 func printable(s string) string {
 	s = strings.Replace(s, "\n", `\n`, -1)
 	s = strings.Replace(s, "\r", `\r`, -1)
 	s = strings.Replace(s, "\t", `\t`, -1)
 	return s
 }
 
-func That(t *testing.T, condition bool, msg ...interface{}) {
+////////////////////////////////////////////////////////////////
+
+func That(t *testing.T, condition bool, msgs ...interface{}) {
 	if !condition {
-		t.Errorf("%s: %s\n", trace(), fmt.Sprint(msg...))
+		t.Errorf("%s: %s", trace(), message("bad assertion", msgs...))
 	}
 }
 
-func Error(t *testing.T, err, expected error, msg ...interface{}) {
+func Error(t *testing.T, err, expected error, msgs ...interface{}) {
 	if err != expected {
-		t.Errorf("%s: %s\n   error: %v\nexpected: %v\n", trace(), fmt.Sprint(msg...), err, expected)
+		t.Errorf("%s: %s   error: %v\nexpected: %v\n", trace(), message("", msgs...), err, expected)
 	}
 }
 
-func String(t *testing.T, output, expected string, msg ...interface{}) {
+func String(t *testing.T, output, expected string, msgs ...interface{}) {
 	if output != expected {
-		t.Errorf("%s: %s\n  output: %s\nexpected: %s\n", trace(), fmt.Sprint(msg...), printable(output), printable(expected))
+		t.Errorf("%s: %s  output: %s\nexpected: %s\n", trace(), message("", msgs...), printable(output), printable(expected))
 	}
 }
 
-func Bytes(t *testing.T, output, expected []byte, msg ...interface{}) {
+func Bytes(t *testing.T, output, expected []byte, msgs ...interface{}) {
 	if !bytes.Equal(output, expected) {
-		t.Errorf("%s: %s\n  output: %s\nexpected: %s\n", trace(), fmt.Sprint(msg...), printable(string(output)), printable(string(expected)))
+		t.Errorf("%s: %s  output: %s\nexpected: %s\n", trace(), message("", msgs...), printable(string(output)), printable(string(expected)))
 	}
 }
 
-func Minify(t *testing.T, input string, err error, output, expected string, msg ...interface{}) {
+func Minify(t *testing.T, input string, err error, output, expected string, msgs ...interface{}) {
 	if err != nil {
-		t.Errorf("%s: %s\n   given: %s\n   error: %v\n", trace(), fmt.Sprint(msg...), printable(input), err)
+		t.Errorf("%s: %s   given: %s\n   error: %v\n", trace(), message("", msgs...), printable(input), err)
 	}
 	if output != expected {
-		t.Errorf("%s: %s\n   given: %s\nminified: %s\nexpected: %s\n", trace(), fmt.Sprint(msg...), printable(input), printable(output), printable(expected))
+		t.Errorf("%s: %s   given: %s\nminified: %s\nexpected: %s\n", trace(), message("", msgs...), printable(input), printable(output), printable(expected))
 	}
 }