Add strip_punctuation modifier (#35)

Author: nchelluri

README.md

@@ -49,6 +49,7 @@ These functions modify the data in-place.
 | strip_num | Strips all ascii numeric characters from the data. |
 | strip_alpha_unicode | Strips all unicode characters from the data. |
 | strip_num_unicode | Strips all unicode numeric characters from the data. |
+| strip_punctuation | Strips all ascii punctuation from the data. |
 
 
 

modifiers/modifiers.go

@@ -23,6 +23,7 @@ func New() *mold.Transformer {
 	mod.Register("strip_num", stripNumCase)
 	mod.Register("strip_num_unicode", stripNumUnicodeCase)
 	mod.Register("strip_alpha_unicode", stripAlphaUnicodeCase)
+	mod.Register("strip_punctuation", stripPunctuation)
 	mod.Register("camel", camelCase)
 	mod.Register("default", defaultValue)
 	return mod

modifiers/string.go

@@ -191,6 +191,17 @@ func stripAlphaUnicodeCase(ctx context.Context, fl mold.FieldLevel) error {
 	return nil
 }
 
+var stripPunctuationRegex = regexp.MustCompile(`[[:punct:]]`)
+
+// stripPunctuation removes punctuation. Example: "# M5W-1E6!!!" -> " M5W1E6"
+func stripPunctuation(ctx context.Context, fl mold.FieldLevel) error {
+	switch fl.Field().Kind() {
+	case reflect.String:
+		fl.Field().SetString(stripPunctuationRegex.ReplaceAllLiteralString(fl.Field().String(), ""))
+	}
+	return nil
+}
+
 // camelCase converts string to camel case
 func camelCase(ctx context.Context, fl mold.FieldLevel) error {
 	switch fl.Field().Kind() {

modifiers/string_test.go

@@ -765,6 +765,52 @@ func TestNotAlphaCase(t *testing.T) {
 	}
 }
 
+func TestPunctuation(t *testing.T) {
+	conform := New()
+
+	s := "# M5W-1E6!!!"
+	expected := " M5W1E6"
+
+	type Test struct {
+		String string `mod:"strip_punctuation"`
+	}
+
+	tt := Test{String: s}
+	err := conform.Struct(context.Background(), &tt)
+	if err != nil {
+		log.Fatal(err)
+	}
+	if tt.String != expected {
+		t.Fatalf("Unexpected value '%s'\n", tt.String)
+	}
+
+	err = conform.Field(context.Background(), &s, "strip_punctuation")
+	if err != nil {
+		log.Fatal(err)
+	}
+	if s != expected {
+		t.Fatalf("Unexpected value '%s'\n", s)
+	}
+
+	var iface interface{}
+	err = conform.Field(context.Background(), &iface, "strip_punctuation")
+	if err != nil {
+		log.Fatal(err)
+	}
+	if iface != nil {
+		t.Fatalf("Unexpected value '%v'\n", nil)
+	}
+
+	iface = s
+	err = conform.Field(context.Background(), &iface, "strip_punctuation")
+	if err != nil {
+		log.Fatal(err)
+	}
+	if iface != expected {
+		t.Fatalf("Unexpected value '%v'\n", iface)
+	}
+}
+
 func TestCamelCase(t *testing.T) {
 	conform := New()