tpl/strings: strings.RuneCount

tpl/strings/init.go

@@ -41,6 +41,11 @@ func init() {
 			[][2]string{},
 		)
 
+		ns.AddMethodMapping(ctx.RuneCount,
+			nil,
+			[][2]string{},
+		)
+
 		ns.AddMethodMapping(ctx.CountWords,
 			[]string{"countwords"},
 			[][2]string{},

tpl/strings/strings.go

@@ -57,6 +57,15 @@ func (ns *Namespace) CountRunes(s interface{}) (int, error) {
 	return counter, nil
 }
 
+// RuneCount returns the number of runes in s.
+func (ns *Namespace) RuneCount(s interface{}) (int, error) {
+	ss, err := cast.ToStringE(s)
+	if err != nil {
+		return 0, fmt.Errorf("Failed to convert content to string: %s", err)
+	}
+	return utf8.RuneCountInString(ss), nil
+}
+
 // CountWords returns the approximate word count in s.
 func (ns *Namespace) CountWords(s interface{}) (int, error) {
 	ss, err := cast.ToStringE(s)

tpl/strings/strings_test.go

@@ -173,6 +173,33 @@ func TestCountRunes(t *testing.T) {
 	}
 }
 
+func TestRuneCount(t *testing.T) {
+	t.Parallel()
+
+	for i, test := range []struct {
+		s      interface{}
+		expect interface{}
+	}{
+		{"foo bar", 7},
+		{"旁边", 2},
+		{`<div class="test">旁边</div>`, 26},
+		// errors
+		{tstNoStringer{}, false},
+	} {
+		errMsg := fmt.Sprintf("[%d] %v", i, test.s)
+
+		result, err := ns.RuneCount(test.s)
+
+		if b, ok := test.expect.(bool); ok && !b {
+			require.Error(t, err, errMsg)
+			continue
+		}
+
+		require.NoError(t, err, errMsg)
+		assert.Equal(t, test.expect, result, errMsg)
+	}
+}
+
 func TestCountWords(t *testing.T) {
 	t.Parallel()