example_format_test.go

     1  // Copyright 2022 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  //go:build goexperiment.jsonv2 && goexperiment.jsonformat
     6  
     7  package json_test
     8  
     9  import (
    10  	"encoding/json/jsontext"
    11  	"encoding/json/v2"
    12  	"fmt"
    13  	"log"
    14  	"math"
    15  	"time"
    16  )
    17  
    18  // The "format" tag option can be used to alter the formatting of certain types.
    19  func Example_formatFlags() {
    20  	value := struct {
    21  		BytesBase64     []byte         `json:",format:base64"`
    22  		BytesHex        [8]byte        `json:",format:hex"`
    23  		BytesArray      []byte         `json:",format:array"`
    24  		FloatNonFinite  float64        `json:",format:nonfinite"`
    25  		MapEmitNull     map[string]any `json:",format:emitnull"`
    26  		SliceEmitNull   []any          `json:",format:emitnull"`
    27  		TimeDateOnly    time.Time      `json:",format:'2006-01-02'"`
    28  		TimeUnixSec     time.Time      `json:",format:unix"`
    29  		DurationSecs    time.Duration  `json:",format:sec"`
    30  		DurationNanos   time.Duration  `json:",format:nano"`
    31  		DurationISO8601 time.Duration  `json:",format:iso8601"`
    32  	}{
    33  		BytesBase64:     []byte{0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef},
    34  		BytesHex:        [8]byte{0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef},
    35  		BytesArray:      []byte{0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef},
    36  		FloatNonFinite:  math.NaN(),
    37  		MapEmitNull:     nil,
    38  		SliceEmitNull:   nil,
    39  		TimeDateOnly:    time.Date(2000, 1, 1, 0, 0, 0, 0, time.UTC),
    40  		TimeUnixSec:     time.Date(2000, 1, 1, 0, 0, 0, 0, time.UTC),
    41  		DurationSecs:    12*time.Hour + 34*time.Minute + 56*time.Second + 7*time.Millisecond + 8*time.Microsecond + 9*time.Nanosecond,
    42  		DurationNanos:   12*time.Hour + 34*time.Minute + 56*time.Second + 7*time.Millisecond + 8*time.Microsecond + 9*time.Nanosecond,
    43  		DurationISO8601: 12*time.Hour + 34*time.Minute + 56*time.Second + 7*time.Millisecond + 8*time.Microsecond + 9*time.Nanosecond,
    44  	}
    45  
    46  	b, err := json.Marshal(&value)
    47  	if err != nil {
    48  		log.Fatal(err)
    49  	}
    50  	(*jsontext.Value)(&b).Indent() // indent for readability
    51  	fmt.Println(string(b))
    52  
    53  	// Output:
    54  	// {
    55  	// 	"BytesBase64": "ASNFZ4mrze8=",
    56  	// 	"BytesHex": "0123456789abcdef",
    57  	// 	"BytesArray": [
    58  	// 		1,
    59  	// 		35,
    60  	// 		69,
    61  	// 		103,
    62  	// 		137,
    63  	// 		171,
    64  	// 		205,
    65  	// 		239
    66  	// 	],
    67  	// 	"FloatNonFinite": "NaN",
    68  	// 	"MapEmitNull": null,
    69  	// 	"SliceEmitNull": null,
    70  	//	"TimeDateOnly": "2000-01-01",
    71  	//	"TimeUnixSec": 946684800,
    72  	//	"DurationSecs": 45296.007008009,
    73  	//	"DurationNanos": 45296007008009,
    74  	//	"DurationISO8601": "PT12H34M56.007008009S"
    75  	// }
    76  }
    77
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