sdk/log/logtest: Add RecordBuilder

sdk/log/logtest/README.md

@@ -0,0 +1,3 @@
+# Log Test SDK
+
+[![PkgGoDev](https://pkg.go.dev/badge/go.opentelemetry.io/otel/sdk/log/logtest)](https://pkg.go.dev/go.opentelemetry.io/otel/sdk/log/logtest)

sdk/log/logtest/builder.go

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+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package logtest // import "go.opentelemetry.io/otel/sdk/log/logtest"
+
+import (
+	"context"
+	"slices"
+	"time"
+
+	"go.opentelemetry.io/otel/log"
+	"go.opentelemetry.io/otel/sdk/instrumentation"
+	sdklog "go.opentelemetry.io/otel/sdk/log"
+	"go.opentelemetry.io/otel/sdk/resource"
+)
+
+// TODO: comment.
+type RecordBuilder struct {
+	timestamp time.Time
+	// TODO: implement all fields
+	// observedTimestamp time.Time
+	// severity          log.Severity
+	// severityText      string
+	// body              log.Value
+	attrs []log.KeyValue
+	// traceID           trace.TraceID
+	// spanID            trace.SpanID
+	// traceFlags        trace.TraceFlags
+
+	resource *resource.Resource
+	scope    instrumentation.Scope
+
+	dropped int
+}
+
+// TODO: comment.
+func (b RecordBuilder) Record() sdklog.Record {
+	var record sdklog.Record
+	p := processor(func(r sdklog.Record) {
+		r.SetTimestamp(b.timestamp)
+		r.SetAttributes(b.attrs...)
+
+		// Generate dropped attributes.
+		for i := 0; i < b.dropped; i++ {
+			r.AddAttributes(log.KeyValue{})
+		}
+
+		record = r
+	})
+
+	attributeCountLimit := -1
+	if b.dropped > 0 {
+		// Make sure that we can generate dropped attributes.
+		attributeCountLimit = len(b.attrs)
+	}
+
+	provider := sdklog.NewLoggerProvider(
+		sdklog.WithResource(b.resource),
+		sdklog.WithAttributeCountLimit(attributeCountLimit),
+		sdklog.WithAttributeValueLengthLimit(-1),
+		sdklog.WithProcessor(p),
+	)
+
+	l := provider.Logger(b.scope.Name,
+		log.WithInstrumentationVersion(b.scope.Version),
+		log.WithSchemaURL(b.scope.SchemaURL),
+	)
+	l.Emit(context.Background(), log.Record{}) // This executes the processor function.
+	return record
+}
+
+// TODO: comment.
+func (b RecordBuilder) SetTimestamp(t time.Time) RecordBuilder {
+	b.timestamp = t
+	return b
+}
+
+// TODO: comment.
+func (b RecordBuilder) AddAttributes(attrs ...log.KeyValue) RecordBuilder {
+	b.attrs = slices.Clone(b.attrs)
+	b.attrs = append(b.attrs, attrs...)
+	return b
+}
+
+// TODO: comment.
+func (b RecordBuilder) SetAttributes(attrs ...log.KeyValue) RecordBuilder {
+	b.attrs = slices.Clone(attrs)
+	return b
+}
+
+// TODO: comment.
+func (b RecordBuilder) SetInstrumentationScope(scope instrumentation.Scope) RecordBuilder {
+	b.scope = scope
+	return b
+}
+
+// TODO: comment.
+func (b RecordBuilder) SetResource(r *resource.Resource) RecordBuilder {
+	b.resource = r
+	return b
+}
+
+// TODO: comment.
+//
+// Notice: The returned record is going to have an attribute count limit.
+// Therefore, it will not be possible to add additional attributes on the record
+// returned by the builder that has dropped attributes set to a value greater than 0
+// (they will be dropped).
+func (b RecordBuilder) SetDroppedAttributes(n int) RecordBuilder {
+	b.dropped = n
+	return b
+}
+
+type processor func(r sdklog.Record)
+
+func (p processor) OnEmit(ctx context.Context, r sdklog.Record) error {
+	p(r)
+	return nil
+}
+
+func (processor) Enabled(context.Context, sdklog.Record) bool {
+	return true
+}
+
+func (processor) Shutdown(ctx context.Context) error {
+	return nil
+}
+
+func (processor) ForceFlush(context.Context) error {
+	return nil
+}

sdk/log/logtest/builder_test.go

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+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package logtest
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/log"
+	"go.opentelemetry.io/otel/sdk/instrumentation"
+	"go.opentelemetry.io/otel/sdk/resource"
+)
+
+func TestRecordBuilder(t *testing.T) {
+	now := time.Now()
+	attrs := []log.KeyValue{
+		log.Int("int", 1),
+		log.String("str", "foo"),
+		log.Float64("flt", 3.14),
+	}
+	dropped := 3
+	scope := instrumentation.Scope{
+		Name: t.Name(),
+	}
+	r := resource.NewSchemaless(attribute.Bool("works", true))
+
+	b := RecordBuilder{}.
+		SetTimestamp(now).
+		SetAttributes(attrs...).
+		SetDroppedAttributes(dropped).
+		SetInstrumentationScope(scope).
+		SetResource(r)
+
+	got := b.Record()
+	var gotAttrs []log.KeyValue
+	got.WalkAttributes(func(kv log.KeyValue) bool {
+		gotAttrs = append(gotAttrs, kv)
+		return true
+	})
+
+	assert.Equal(t, now, got.Timestamp())
+	assert.Equal(t, attrs, gotAttrs)
+	assert.Equal(t, dropped, got.DroppedAttributes())
+	assert.Equal(t, scope, got.InstrumentationScope())
+	assert.Equal(t, *r, got.Resource())
+
+	got = b.AddAttributes(log.Bool("added", true)).Record()
+	gotAttrs = nil
+	got.WalkAttributes(func(kv log.KeyValue) bool {
+		gotAttrs = append(gotAttrs, kv)
+		return true
+	})
+
+	assert.Equal(t, now, got.Timestamp())
+	assert.Equal(t, append(attrs, log.Bool("added", true)), gotAttrs)
+	assert.Equal(t, dropped, got.DroppedAttributes())
+	assert.Equal(t, scope, got.InstrumentationScope())
+	assert.Equal(t, *r, got.Resource())
+}