From 92d0d365285d6982df542f64cbbc4312a88b0e82 Mon Sep 17 00:00:00 2001
From: Alex Boten <223565+codeboten@users.noreply.github.com>
Date: Wed, 21 Aug 2024 12:10:23 -0700
Subject: [PATCH] add test for generated methods

Signed-off-by: Alex Boten <223565+codeboten@users.noreply.github.com>
---
 cmd/mdatagen/main_test.go | 122 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 122 insertions(+)

diff --git a/cmd/mdatagen/main_test.go b/cmd/mdatagen/main_test.go
index 1372c31d5c5..ed7346cb1cd 100644
--- a/cmd/mdatagen/main_test.go
+++ b/cmd/mdatagen/main_test.go
@@ -15,6 +15,7 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/pdata/pmetric"
 )
 
 func TestRunContents(t *testing.T) {
@@ -620,6 +621,127 @@ func LeveledMeter(settings component.TelemetrySettings, level configtelemetry.Le
 func Tracer(settings component.TelemetrySettings) trace.Tracer {
 	return settings.TracerProvider.Tracer("")
 }
+`,
+		},
+		{
+			name: "foo component with internal telemetry",
+			md: metadata{
+				Type: "foo",
+				Status: &Status{
+					Stability: map[component.StabilityLevel][]string{
+						component.StabilityLevelAlpha: {"metrics"},
+					},
+					Distributions: []string{"contrib"},
+					Class:         "receiver",
+				},
+				Telemetry: telemetry{
+					Metrics: map[metricName]metric{
+						"metric1": {
+							Enabled: true,
+							Sum: &sum{
+								Async:           false,
+								Mono:            Mono{true},
+								MetricValueType: MetricValueType{ValueType: pmetric.NumberDataPointValueTypeInt},
+							},
+						},
+						"metric2": {
+							Enabled: true,
+							Sum: &sum{
+								Async:           true,
+								Mono:            Mono{false},
+								MetricValueType: MetricValueType{ValueType: pmetric.NumberDataPointValueTypeDouble},
+							},
+						},
+					},
+				},
+			},
+			expected: `// Code generated by mdatagen. DO NOT EDIT.
+
+package metadata
+
+import (
+	"context"
+	"errors"
+
+	"go.opentelemetry.io/otel/metric"
+	"go.opentelemetry.io/otel/metric/noop"
+	"go.opentelemetry.io/otel/trace"
+
+	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/config/configtelemetry"
+)
+
+func Meter(settings component.TelemetrySettings) metric.Meter {
+	return settings.MeterProvider.Meter("")
+}
+
+func Tracer(settings component.TelemetrySettings) trace.Tracer {
+	return settings.TracerProvider.Tracer("")
+}
+
+// TelemetryBuilder provides an interface for components to report telemetry
+// as defined in metadata and user config.
+type TelemetryBuilder struct {
+	meter          metric.Meter
+	Metric1        metric.Int64Counter
+	Metric2        metric.Float64ObservableUpDownCounter
+	observeMetric2 func(context.Context, metric.Observer) error
+	level          configtelemetry.Level
+}
+
+// telemetryBuilderOption applies changes to default builder.
+type telemetryBuilderOption func(*TelemetryBuilder)
+
+// WithLevel sets the current telemetry level for the component.
+func WithLevel(lvl configtelemetry.Level) telemetryBuilderOption {
+	return func(builder *TelemetryBuilder) {
+		builder.level = lvl
+	}
+}
+
+// WithMetric2Callback sets callback for observable Metric2 metric.
+func WithMetric2Callback(cb func() float64, opts ...metric.ObserveOption) telemetryBuilderOption {
+	return func(builder *TelemetryBuilder) {
+		builder.observeMetric2 = func(_ context.Context, o metric.Observer) error {
+			o.ObserveFloat64(builder.Metric2, cb(), opts...)
+			return nil
+		}
+	}
+}
+
+// NewTelemetryBuilder provides a struct with methods to update all internal telemetry
+// for a component
+func NewTelemetryBuilder(settings component.TelemetrySettings, options ...telemetryBuilderOption) (*TelemetryBuilder, error) {
+	builder := TelemetryBuilder{level: configtelemetry.LevelBasic}
+	for _, op := range options {
+		op(&builder)
+	}
+	var err, errs error
+	if builder.level >= configtelemetry.LevelBasic {
+		builder.meter = Meter(settings)
+	} else {
+		builder.meter = noop.Meter{}
+	}
+	builder.Metric1, err = builder.meter.Int64Counter(
+		"otelcol_metric1",
+		metric.WithDescription(""),
+		metric.WithUnit("<nil>"),
+	)
+	errs = errors.Join(errs, err)
+	builder.Metric2, err = builder.meter.Float64ObservableUpDownCounter(
+		"otelcol_metric2",
+		metric.WithDescription(""),
+		metric.WithUnit("<nil>"),
+	)
+	errs = errors.Join(errs, err)
+	_, err = builder.meter.RegisterCallback(builder.observeMetric2, builder.Metric2)
+	errs = errors.Join(errs, err)
+	return &builder, errs
+}
+
+func (b *TelemetryBuilder) RecordMetric1(ctx context.Context, val int64, opts ...metric.AddOption) {
+	b.Metric1.Add(ctx, val, opts...)
+}
 `,
 		},
 	}