example_test.go

Documentation: cdr.dev/slog

     1  package slog_test
     2  
     3  import (
     4  	"context"
     5  	"io"
     6  	"net"
     7  	"os"
     8  	"testing"
     9  	"time"
    10  
    11  	"go.opencensus.io/trace"
    12  	"golang.org/x/xerrors"
    13  
    14  	"cdr.dev/slog"
    15  	"cdr.dev/slog/sloggers/sloghuman"
    16  	"cdr.dev/slog/sloggers/slogstackdriver"
    17  	"cdr.dev/slog/sloggers/slogtest"
    18  )
    19  
    20  func Example() {
    21  	log := slog.Make(sloghuman.Sink(os.Stdout))
    22  
    23  	log.Info(context.Background(), "my message here",
    24  		slog.F("field_name", "something or the other"),
    25  		slog.F("some_map", slog.M(
    26  			slog.F("nested_fields", time.Date(2000, time.February, 5, 4, 4, 4, 0, time.UTC)),
    27  		)),
    28  		slog.Error(
    29  			xerrors.Errorf("wrap1: %w",
    30  				xerrors.Errorf("wrap2: %w",
    31  					io.EOF,
    32  				),
    33  			),
    34  		),
    35  	)
    36  
    37  	// 2019-12-09 05:04:53.398 [INFO]	<example.go:16>	my message here	{"field_name": "something or the other", "some_map": {"nested_fields": "2000-02-05T04:04:04Z"}} ...
    38  	//  "error": wrap1:
    39  	//      main.main
    40  	//          /Users/nhooyr/src/cdr/scratch/example.go:22
    41  	//    - wrap2:
    42  	//      main.main
    43  	//          /Users/nhooyr/src/cdr/scratch/example.go:23
    44  	//    - EOF
    45  }
    46  
    47  func Example_struct() {
    48  	l := slog.Make(sloghuman.Sink(os.Stdout))
    49  
    50  	type hello struct {
    51  		Meow int       `json:"meow"`
    52  		Bar  string    `json:"bar"`
    53  		M    time.Time `json:"m"`
    54  	}
    55  
    56  	l.Info(context.Background(), "check out my structure",
    57  		slog.F("hello", hello{
    58  			Meow: 1,
    59  			Bar:  "barbar",
    60  			M:    time.Date(2000, time.February, 5, 4, 4, 4, 0, time.UTC),
    61  		}),
    62  	)
    63  
    64  	// 2019-12-16 17:31:51.769 [INFO]	<example_test.go:56>	check out my structure	{"hello": {"meow": 1, "bar": "barbar", "m": "2000-02-05T04:04:04Z"}}
    65  }
    66  
    67  func Example_testing() {
    68  	// Provided by the testing package in tests.
    69  	var t testing.TB
    70  
    71  	slogtest.Info(t, "my message here",
    72  		slog.F("field_name", "something or the other"),
    73  	)
    74  
    75  	// t.go:55: 2019-12-05 21:20:31.218 [INFO]	<examples_test.go:42>	my message here	{"field_name": "something or the other"}
    76  }
    77  
    78  func Example_tracing() {
    79  	log := slog.Make(sloghuman.Sink(os.Stdout))
    80  
    81  	ctx, _ := trace.StartSpan(context.Background(), "spanName")
    82  
    83  	log.Info(ctx, "my msg", slog.F("hello", "hi"))
    84  
    85  	// 2019-12-09 21:59:48.110 [INFO]	<example_test.go:62>	my msg	{"trace": "f143d018d00de835688453d8dc55c9fd", "span": "f214167bf550afc3", "hello": "hi"}
    86  }
    87  
    88  func Example_multiple() {
    89  	l := slog.Make(sloghuman.Sink(os.Stdout))
    90  
    91  	f, err := os.OpenFile("stackdriver", os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0644)
    92  	if err != nil {
    93  		l.Fatal(context.Background(), "failed to open stackdriver log file", slog.Error(err))
    94  	}
    95  
    96  	l = l.AppendSinks(slogstackdriver.Sink(f))
    97  
    98  	l.Info(context.Background(), "log to stdout and stackdriver")
    99  
   100  	// 2019-12-07 20:59:55.790 [INFO]	<example_test.go:46>	log to stdout and stackdriver
   101  }
   102  
   103  func ExampleWith() {
   104  	ctx := slog.With(context.Background(), slog.F("field", 1))
   105  
   106  	l := slog.Make(sloghuman.Sink(os.Stdout))
   107  	l.Info(ctx, "msg")
   108  
   109  	// 2019-12-07 20:54:23.986 [INFO]	<example_test.go:20>	msg	{"field": 1}
   110  }
   111  
   112  func ExampleStdlib() {
   113  	ctx := slog.With(context.Background(), slog.F("field", 1))
   114  	l := slog.Stdlib(ctx, slog.Make(sloghuman.Sink(os.Stdout)), slog.LevelInfo)
   115  
   116  	l.Print("msg")
   117  
   118  	// 2019-12-07 20:54:23.986 [INFO]	(stdlib)	<example_test.go:29>	msg	{"field": 1}
   119  }
   120  
   121  func ExampleLogger_Named() {
   122  	ctx := context.Background()
   123  
   124  	l := slog.Make(sloghuman.Sink(os.Stdout))
   125  	l = l.Named("http")
   126  	l.Info(ctx, "received request", slog.F("remote address", net.IPv4(127, 0, 0, 1)))
   127  
   128  	// 2019-12-07 21:20:56.974 [INFO]	(http)	<example_test.go:85>	received request	{"remote address": "127.0.0.1"}
   129  }
   130  
   131  func ExampleLogger_Leveled() {
   132  	ctx := context.Background()
   133  
   134  	l := slog.Make(sloghuman.Sink(os.Stdout))
   135  	l.Debug(ctx, "testing1")
   136  	l.Info(ctx, "received request")
   137  
   138  	l = l.Leveled(slog.LevelDebug)
   139  
   140  	l.Debug(ctx, "testing2")
   141  
   142  	// 2019-12-07 21:26:20.945 [INFO]	<example_test.go:95>	received request
   143  	// 2019-12-07 21:26:20.945 [DEBUG]	<example_test.go:99>	testing2
   144  }
   145
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