github.1485827954.workers.dev/ethereum/go-ethereum@v1.14.3/metrics/prometheus/collector_test.go (about)

     1  // Copyright 2023 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package prometheus
    18  
    19  import (
    20  	"fmt"
    21  	"os"
    22  	"strings"
    23  	"testing"
    24  
    25  	"github.com/ethereum/go-ethereum/metrics"
    26  	"github.com/ethereum/go-ethereum/metrics/internal"
    27  )
    28  
    29  func TestMain(m *testing.M) {
    30  	metrics.Enabled = true
    31  	os.Exit(m.Run())
    32  }
    33  
    34  func TestCollector(t *testing.T) {
    35  	var (
    36  		c    = newCollector()
    37  		want string
    38  	)
    39  	internal.ExampleMetrics().Each(func(name string, i interface{}) {
    40  		c.Add(name, i)
    41  	})
    42  	if wantB, err := os.ReadFile("./testdata/prometheus.want"); err != nil {
    43  		t.Fatal(err)
    44  	} else {
    45  		want = string(wantB)
    46  	}
    47  	if have := c.buff.String(); have != want {
    48  		t.Logf("have\n%v", have)
    49  		t.Logf("have vs want:\n%v", findFirstDiffPos(have, want))
    50  		t.Fatalf("unexpected collector output")
    51  	}
    52  }
    53  
    54  func findFirstDiffPos(a, b string) string {
    55  	yy := strings.Split(b, "\n")
    56  	for i, x := range strings.Split(a, "\n") {
    57  		if i >= len(yy) {
    58  			return fmt.Sprintf("have:%d: %s\nwant:%d: <EOF>", i, x, i)
    59  		}
    60  		if y := yy[i]; x != y {
    61  			return fmt.Sprintf("have:%d: %s\nwant:%d: %s", i, x, i, y)
    62  		}
    63  	}
    64  	return ""
    65  }