feat: add Pretty and PrettyToWriter

formatter/formatter_test.go

@@ -1,6 +1,7 @@
 package formatter
 
 import (
+	"bytes"
 	"testing"
 
 	"github.com/duke-git/lancet/v2/internal"
@@ -26,3 +27,54 @@ func TestComma(t *testing.T) {
 	assert.Equal("12,345,678.9", Comma(12345678.9, ""))
 	assert.Equal("123,456,789,000", Comma(123456789000, ""))
 }
+
+func TestPretty(t *testing.T) {
+	assert := internal.NewAssert(t, "TestPretty")
+
+	cases := []any{
+		"",
+		"abc",
+		123,
+		[]string{"a", "b", "c"},
+		map[string]int{"a": 1},
+		struct {
+			Abc int `json:"abc"`
+		}{Abc: 123},
+	}
+
+	expects := []string{
+		"\"\"",
+		`"abc"`,
+		"123",
+		"[\n    \"a\",\n    \"b\",\n    \"c\"\n]",
+		"{\n    \"a\": 1\n}",
+		"{\n    \"abc\": 123\n}",
+	}
+
+	for i, v := range cases {
+		result, err := Pretty(v)
+
+		assert.IsNil(err)
+
+		t.Log("result -> ", result)
+		assert.Equal(expects[i], result)
+	}
+}
+
+func TestPrettyToWriter(t *testing.T) {
+	assert := internal.NewAssert(t, "TestPrettyToWriter")
+
+	type User struct {
+		Name string `json:"name"`
+		Aage uint   `json:"age"`
+	}
+	user := User{Name: "King", Aage: 10000}
+
+	expects := "{\n    \"name\": \"King\",\n    \"age\": 10000\n}\n"
+
+	buf := &bytes.Buffer{}
+	err := PrettyToWriter(user, buf)
+
+	assert.IsNil(err)
+	assert.Equal(expects, buf.String())
+}