example_test.go

Documentation: golang.org/x/exp/slog/slogtest

     1  package slogtest_test
     2  
     3  import (
     4  	"bytes"
     5  	"encoding/json"
     6  	"fmt"
     7  
     8  	"golang.org/x/exp/slog"
     9  	"golang.org/x/exp/slog/slogtest"
    10  )
    11  
    12  // This example demonstrates one technique for testing a handler with this
    13  // package. The handler is given a [bytes.Buffer] to write to, and each line
    14  // of the resulting output is parsed.
    15  // For JSON output, [encoding/json.Unmarshal] produces a result in the desired
    16  // format when given a pointer to a map[string]any.
    17  func Example_parsing() {
    18  	var buf bytes.Buffer
    19  	h := slog.NewJSONHandler(&buf, nil)
    20  
    21  	results := func() []map[string]any {
    22  		var ms []map[string]any
    23  		for _, line := range bytes.Split(buf.Bytes(), []byte{'\n'}) {
    24  			if len(line) == 0 {
    25  				continue
    26  			}
    27  			var m map[string]any
    28  			if err := json.Unmarshal(line, &m); err != nil {
    29  				panic(err) // In a real test, use t.Fatal.
    30  			}
    31  			ms = append(ms, m)
    32  		}
    33  		return ms
    34  	}
    35  	err := slogtest.TestHandler(h, results)
    36  	fmt.Println(err)
    37  
    38  	// Output:
    39  	// <nil>
    40  }
    41
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