code review 5234041: utf8: add Valid and ValidString

src/pkg/utf8/utf8_test.go

 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 package utf8_test
 
 import (
         "bytes"
         "testing"
         . "utf8"
@@ skipping 256 matching lines @@
                 tt := runecounttests[i]
                 if out := RuneCountInString(tt.in); out != tt.out {
                         t.Errorf("RuneCountInString(%q) = %d, want %d", tt.in, out, tt.out)
                 }
                 if out := RuneCount([]byte(tt.in)); out != tt.out {
                         t.Errorf("RuneCount(%q) = %d, want %d", tt.in, out, tt.out)
                 }
         }
 }
 
+type ValidTest struct {
+        in  string
+        out bool
+}
+
+var validTests = []ValidTest{
+        {"", true},
+        {"a", true},
+        {"abc", true},
+        {"Ж", true},
+        {"ЖЖ", true},
+        {"брэд-ЛГТМ", true},
+        {"☺☻☹", true},
+        {string([]byte{66, 250}), false},
+        {string([]byte{66, 250, 67}), false},
+        {"a\uFFFDb", true},
+}
+
+func TestValid(t *testing.T) {
+        for i, tt := range validTests {
+                if Valid([]byte(tt.in)) != tt.out {
+                        t.Errorf("%d. Valid(%q) = %v; want %v", i, tt.in, !tt.out, tt.out)
+                }
+                if ValidString(tt.in) != tt.out {
+                        t.Errorf("%d. ValidString(%q) = %v; want %v", i, tt.in, !tt.out, tt.out)
+                }
+        }
+}
+
 func BenchmarkRuneCountTenASCIIChars(b *testing.B) {
         for i := 0; i < b.N; i++ {
                 RuneCountInString("0123456789")
         }
 }
 
 func BenchmarkRuneCountTenJapaneseChars(b *testing.B) {
         for i := 0; i < b.N; i++ {
                 RuneCountInString("日本語日本語日本語日")
         }
@@ skipping 19 matching lines @@
                 DecodeRune(a)
         }
 }
 
 func BenchmarkDecodeJapaneseRune(b *testing.B) {
         nihon := []byte("本")
         for i := 0; i < b.N; i++ {
                 DecodeRune(nihon)
         }
 }