feat: add Pretty and PrettyToWriter

docs/formatter.md

@@ -23,6 +23,8 @@ import (
 ## Index
 
 -   [Comma](#Comma)
+-   [Pretty](#Pretty)
+-   [PrettyToWriter](#PrettyToWriter)
 
 <div STYLE="page-break-after: always;"></div>
 
@@ -63,3 +65,85 @@ func main() {
     // ￥1,234,567
 }
 ```
+
+### <span id="Pretty">Pretty</span>
+
+<p>Pretty data to JSON string.</p>
+
+<b>Signature:</b>
+
+```go
+func Pretty(v any) (string, error)
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/formatter"
+)
+
+func main() {
+    result1, _ := formatter.Pretty([]string{"a", "b", "c"})
+    result2, _ := formatter.Pretty(map[string]int{"a": 1})
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+
+    // Output:
+    // [
+    //     "a",
+    //     "b",
+    //     "c"
+    // ]
+    // {
+    //     "a": 1
+    // }
+}
+```
+
+### <span id="PrettyToWriter">PrettyToWriter</span>
+
+<p>Pretty encode data to writer.</p>
+
+<b>Signature:</b>
+
+```go
+func PrettyToWriter(v any, out io.Writer) error
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/formatter"
+)
+
+func main() {
+    type User struct {
+        Name string `json:"name"`
+        Aage uint   `json:"age"`
+    }
+    user := User{Name: "King", Aage: 10000}
+
+    buf := &bytes.Buffer{}
+    err := formatter.PrettyToWriter(user, buf)
+
+    fmt.Println(buf)
+    fmt.Println(err)
+
+    // Output:
+    // {
+    //     "name": "King",
+    //     "age": 10000
+    // }
+    //
+    // <nil>
+}
+```

docs/formatter_zh-CN.md

@@ -23,6 +23,8 @@ import (
 ## 目录
 
 -   [Comma](#Comma)
+-   [Pretty](#Pretty)
+-   [PrettyToWriter](#PrettyToWriter)
 
 <div STYLE="page-break-after: always;"></div>
 
@@ -63,3 +65,85 @@ func main() {
     // ￥1,234,567
 }
 ```
+
+### <span id="Pretty">Pretty</span>
+
+<p>返回pretty JSON字符串.</p>
+
+<b>函数签名:</b>
+
+```go
+func Pretty(v any) (string, error)
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/formatter"
+)
+
+func main() {
+    result1, _ := formatter.Pretty([]string{"a", "b", "c"})
+    result2, _ := formatter.Pretty(map[string]int{"a": 1})
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+
+    // Output:
+    // [
+    //     "a",
+    //     "b",
+    //     "c"
+    // ]
+    // {
+    //     "a": 1
+    // }
+}
+```
+
+### <span id="PrettyToWriter">PrettyToWriter</span>
+
+<p>Pretty encode数据到writer。</p>
+
+<b>函数签名:</b>
+
+```go
+func PrettyToWriter(v any, out io.Writer) error
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/formatter"
+)
+
+func main() {
+    type User struct {
+        Name string `json:"name"`
+        Aage uint   `json:"age"`
+    }
+    user := User{Name: "King", Aage: 10000}
+
+    buf := &bytes.Buffer{}
+    err := formatter.PrettyToWriter(user, buf)
+
+    fmt.Println(buf)
+    fmt.Println(err)
+
+    // Output:
+    // {
+    //     "name": "King",
+    //     "age": 10000
+    // }
+    //
+    // <nil>
+}
+```

formatter/formatter.go

@@ -5,7 +5,9 @@
 package formatter
 
 import (
+	"encoding/json"
 	"fmt"
+	"io"
 
 	"github.com/duke-git/lancet/v2/convertor"
 	"github.com/duke-git/lancet/v2/strutil"
@@ -44,3 +46,23 @@ func Comma[T constraints.Float | constraints.Integer | string](value T, symbol s
 
 	return ""
 }
+
+// Pretty data to JSON string.
+// Play: todo
+func Pretty(v any) (string, error) {
+	out, err := json.MarshalIndent(v, "", "    ")
+	return string(out), err
+}
+
+// PrettyToWriter pretty encode data to writer.
+// Play: todo
+func PrettyToWriter(v any, out io.Writer) error {
+	enc := json.NewEncoder(out)
+	enc.SetIndent("", "    ")
+
+	if err := enc.Encode(v); err != nil {
+		return err
+	}
+
+	return nil
+}

formatter/formatter_example_test.go

@@ -1,6 +1,9 @@
 package formatter
 
-import "fmt"
+import (
+	"bytes"
+	"fmt"
+)
 
 func ExampleComma() {
 	result1 := Comma("123", "")
@@ -16,3 +19,43 @@ func ExampleComma() {
 	// $12,345
 	// ￥1,234,567
 }
+
+func ExamplePretty() {
+	result1, _ := Pretty([]string{"a", "b", "c"})
+	result2, _ := Pretty(map[string]int{"a": 1})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+
+	// Output:
+	// [
+	//     "a",
+	//     "b",
+	//     "c"
+	// ]
+	// {
+	//     "a": 1
+	// }
+}
+
+func ExamplePrettyToWriter() {
+	type User struct {
+		Name string `json:"name"`
+		Aage uint   `json:"age"`
+	}
+	user := User{Name: "King", Aage: 10000}
+
+	buf := &bytes.Buffer{}
+	err := PrettyToWriter(user, buf)
+
+	fmt.Println(buf)
+	fmt.Println(err)
+
+	// Output:
+	// {
+	//     "name": "King",
+	//     "age": 10000
+	// }
+	//
+	// <nil>
+}

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())
+}