github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4: go.Metric

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify github.com/prometheus/client_model/go.Metric in pkg:golang/github.com/prometheus/client_model@v0.0.0-20190812154241-14fe0d1b01d4
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/prometheus/client_model@v0.0.0-20190812154241-14fe0d1b01d4
Demonstrate these symbols/APIs:
  - github.com/prometheus/client_model/go.Metric

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:e45609adaf47cd9ca0197145011bcfc9e6554f12567b98e5db682fb40bba8a45","contract":["dto.Metric getter methods (GetLabel, GetGauge, GetCounter, GetSummary, GetUntyped, GetHistogram, GetTimestampMs) return nil or zero for nil and empty instances.","dto.Metric stores and retrieves labels, gauge metric value, and timestamp in milliseconds.","dto.Metric stores and retrieves counter metric value.","dto.Metric.Reset clears all fields back to zero values."],"goal":"verify github.com/prometheus/client_model/go.Metric in pkg:golang/github.com/prometheus/client_model@v0.0.0-20190812154241-14fe0d1b01d4","kind":"HOW","packages":["pkg:golang/github.com/prometheus/client_model@v0.0.0-20190812154241-14fe0d1b01d4"],"schemaVersion":1,"symbols":["github.com/prometheus/client_model/go.Metric"]},"contractCommand":["go","test","./..."],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","executionContext":"go","language":"go","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","runtime":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/github.com/prometheus/client_model@v0.0.0-20190812154241-14fe0d1b01d4"],"schemaVersion":1,"subject":"pkg:golang/github.com/prometheus/client_model@v0.0.0-20190812154241-14fe0d1b01d4","symbols":["github.com/prometheus/client_model/go.Metric"],"verifierAdapter":"golang@1"}

module example.com/metric

go 1.22

require github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4

require github.com/golang/protobuf v1.2.0 // indirect

github.com/golang/protobuf v1.2.0 h1:P3YflyNX/ehuJFLhxviNdFxQPkGK5cDcApsge1SqnvM=
github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4 h1:gQz4mCbXsO+nc9n1hCxHcGA3Zx3Eo+UHZoInFGUIXNM=
github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
golang.org/x/sync v0.0.0-20181108010431-42b317875d0f h1:Bl/8QSvNqXvPGPGXa2z5xUTmV7VDcZyvRZ+QQXkXTZQ=
golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=

package main

import (
	"fmt"

	dto "github.com/prometheus/client_model/go"
)

func strPtr(s string) *string    { return &s }
func floatPtr(f float64) *float64 { return &f }
func int64Ptr(i int64) *int64     { return &i }

func main() {
	metric := &dto.Metric{
		Label: []*dto.LabelPair{
			{
				Name:  strPtr("method"),
				Value: strPtr("GET"),
			},
		},
		Gauge: &dto.Gauge{
			Value: floatPtr(42.5),
		},
		TimestampMs: int64Ptr(1700000000000),
	}

	fmt.Printf("Labels: %d\n", len(metric.GetLabel()))
	if g := metric.GetGauge(); g != nil {
		fmt.Printf("Gauge: %f\n", g.GetValue())
	}
	fmt.Printf("TimestampMs: %d\n", metric.GetTimestampMs())

	metric.Reset()
	fmt.Printf("After Reset, labels: %d\n", len(metric.GetLabel()))
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/prometheus/client_model/go.Metric in pkg:golang/github.com/prometheus/client_model@v0.0.0-20190812154241-14fe0d1b01d4",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/prometheus/client_model@v0.0.0-20190812154241-14fe0d1b01d4"
  ],
  "symbols": [
    "github.com/prometheus/client_model/go.Metric"
  ]
}

package test

import (
	"testing"

	dto "github.com/prometheus/client_model/go"
)

func strPtr(s string) *string     { return &s }
func floatPtr(f float64) *float64 { return &f }
func int64Ptr(i int64) *int64     { return &i }

func TestMetricNilAndDefaults(t *testing.T) {
	var nilMetric *dto.Metric
	if got := nilMetric.GetLabel(); got != nil {
		t.Errorf("nilMetric.GetLabel() = %v, want nil", got)
	}
	if got := nilMetric.GetGauge(); got != nil {
		t.Errorf("nilMetric.GetGauge() = %v, want nil", got)
	}
	if got := nilMetric.GetCounter(); got != nil {
		t.Errorf("nilMetric.GetCounter() = %v, want nil", got)
	}
	if got := nilMetric.GetSummary(); got != nil {
		t.Errorf("nilMetric.GetSummary() = %v, want nil", got)
	}
	if got := nilMetric.GetUntyped(); got != nil {
		t.Errorf("nilMetric.GetUntyped() = %v, want nil", got)
	}
	if got := nilMetric.GetHistogram(); got != nil {
		t.Errorf("nilMetric.GetHistogram() = %v, want nil", got)
	}
	if got := nilMetric.GetTimestampMs(); got != 0 {
		t.Errorf("nilMetric.GetTimestampMs() = %v, want 0", got)
	}

	emptyMetric := &dto.Metric{}
	if got := emptyMetric.GetLabel(); got != nil {
		t.Errorf("emptyMetric.GetLabel() = %v, want nil", got)
	}
	if got := emptyMetric.GetGauge(); got != nil {
		t.Errorf("emptyMetric.GetGauge() = %v, want nil", got)
	}
	if got := emptyMetric.GetTimestampMs(); got != 0 {
		t.Errorf("emptyMetric.GetTimestampMs() = %v, want 0", got)
	}
}

func TestMetricWithLabelsAndGauge(t *testing.T) {
	labelName := "handler"
	labelVal := "prometheus"
	gaugeVal := 99.5
	ts := int64(1690000000123)

	metric := &dto.Metric{
		Label: []*dto.LabelPair{
			{
				Name:  strPtr(labelName),
				Value: strPtr(labelVal),
			},
		},
		Gauge: &dto.Gauge{
			Value: floatPtr(gaugeVal),
		},
		TimestampMs: int64Ptr(ts),
	}

	labels := metric.GetLabel()
	if len(labels) != 1 {
		t.Fatalf("len(metric.GetLabel()) = %d, want 1", len(labels))
	}
	if labels[0].GetName() != labelName || labels[0].GetValue() != labelVal {
		t.Errorf("label mismatch: got name=%s val=%s, want name=%s val=%s",
			labels[0].GetName(), labels[0].GetValue(), labelName, labelVal)
	}

	gauge := metric.GetGauge()
	if gauge == nil {
		t.Fatal("metric.GetGauge() returned nil")
	}
	if gauge.GetValue() != gaugeVal {
		t.Errorf("gauge.GetValue() = %v, want %v", gauge.GetValue(), gaugeVal)
	}

	if metric.GetTimestampMs() != ts {
		t.Errorf("metric.GetTimestampMs() = %v, want %v", metric.GetTimestampMs(), ts)
	}
}

func TestMetricWithCounter(t *testing.T) {
	counterVal := 1500.0
	metric := &dto.Metric{
		Counter: &dto.Counter{
			Value: floatPtr(counterVal),
		},
	}

	counter := metric.GetCounter()
	if counter == nil {
		t.Fatal("metric.GetCounter() returned nil")
	}
	if counter.GetValue() != counterVal {
		t.Errorf("counter.GetValue() = %v, want %v", counter.GetValue(), counterVal)
	}
}

func TestMetricReset(t *testing.T) {
	metric := &dto.Metric{
		Label: []*dto.LabelPair{
			{
				Name:  strPtr("service"),
				Value: strPtr("web"),
			},
		},
		Gauge: &dto.Gauge{
			Value: floatPtr(10.0),
		},
		TimestampMs: int64Ptr(123456789),
	}

	metric.Reset()

	if got := metric.GetLabel(); got != nil {
		t.Errorf("after Reset(), metric.GetLabel() = %v, want nil", got)
	}
	if got := metric.GetGauge(); got != nil {
		t.Errorf("after Reset(), metric.GetGauge() = %v, want nil", got)
	}
	if got := metric.GetTimestampMs(); got != 0 {
		t.Errorf("after Reset(), metric.GetTimestampMs() = %v, want 0", got)
	}
}