log/logtest: add Error field to Record type (#8148)

Fixes https://github.com/open-telemetry/opentelemetry-go/issues/8147

log/logtest/assert.go

@@ -34,6 +34,7 @@ func AssertEqual[T Recording | Record](t TestingT, want, got T, opts ...AssertOp
 		cmpopts.SortSlices(
 			func(a, b log.KeyValue) bool { return a.Key < b.Key },
 		), // Unordered compare of the key values.
+		cmpopts.EquateErrors(),
 		cmpopts.EquateEmpty(), // Empty and nil collections are equal.
 	}
 	cmpOpts = append(cmpOpts, cfg.cmpOpts...)

log/logtest/assert_test.go

@@ -4,6 +4,7 @@
 package logtest
 
 import (
+	"errors"
 	"fmt"
 	"testing"
 	"time"
@@ -14,7 +15,10 @@ import (
 	"go.opentelemetry.io/otel/log"
 )
 
-var y2k = time.Date(2000, time.January, 1, 0, 0, 0, 0, time.UTC)
+var (
+	y2k     = time.Date(2000, time.January, 1, 0, 0, 0, 0, time.UTC)
+	errBoom = errors.New("boom")
+)
 
 // Compile-time check to ensure testing structs implement TestingT.
 var (
@@ -63,6 +67,7 @@ func TestAssertEqualRecording(t *testing.T) {
 					{
 						Timestamp:  y2k,
 						Context:    t.Context(),
+						Error:      errBoom,
 						Attributes: []log.KeyValue{log.Int("n", 1), log.String("foo", "bar")},
 					},
 				},
@@ -72,6 +77,7 @@ func TestAssertEqualRecording(t *testing.T) {
 					{
 						Timestamp:  y2k,
 						Context:    t.Context(),
+						Error:      errBoom,
 						Attributes: []log.KeyValue{log.String("foo", "bar"), log.Int("n", 1)},
 					},
 				},
@@ -145,11 +151,13 @@ func TestAssertEqualRecord(t *testing.T) {
 			a: Record{
 				Timestamp:  y2k,
 				Context:    t.Context(),
+				Error:      errBoom,
 				Attributes: []log.KeyValue{log.Int("n", 1), log.String("foo", "bar")},
 			},
 			b: Record{
 				Timestamp:  y2k,
 				Context:    t.Context(),
+				Error:      errBoom,
 				Attributes: []log.KeyValue{log.String("foo", "bar"), log.Int("n", 1)},
 			},
 			want: true,

log/logtest/recorder.go

@@ -88,6 +88,7 @@ type Record struct {
 	Severity          log.Severity
 	SeverityText      string
 	Body              log.Value
+	Error             error
 	Attributes        []log.KeyValue
 }
 
@@ -219,6 +220,7 @@ func (l *logger) Emit(ctx context.Context, record log.Record) {
 		Severity:          record.Severity(),
 		SeverityText:      record.SeverityText(),
 		Body:              record.Body(),
+		Error:             record.Err(),
 		Attributes:        attrs,
 	}
 

log/logtest/recorder_test.go

@@ -5,6 +5,7 @@ package logtest
 
 import (
 	"context"
+	"errors"
 	"sync"
 	"testing"
 	"time"
@@ -102,6 +103,7 @@ func TestLoggerEnabledFnUnset(t *testing.T) {
 func TestRecorderLoggerEmitAndReset(t *testing.T) {
 	rec := NewRecorder()
 	ts := time.Now()
+	errBoom := errors.New("boom")
 
 	l := rec.Logger(t.Name())
 	ctx := t.Context()
@@ -109,6 +111,7 @@ func TestRecorderLoggerEmitAndReset(t *testing.T) {
 	r.SetTimestamp(ts)
 	r.SetSeverity(log.SeverityInfo)
 	r.SetBody(log.StringValue("Hello there"))
+	r.SetErr(errBoom)
 	r.AddAttributes(log.Int("n", 1))
 	r.AddAttributes(log.String("foo", "bar"))
 	l.Emit(ctx, r)
@@ -125,6 +128,7 @@ func TestRecorderLoggerEmitAndReset(t *testing.T) {
 				Timestamp: ts,
 				Severity:  log.SeverityInfo,
 				Body:      log.StringValue("Hello there"),
+				Error:     errBoom,
 				Attributes: []log.KeyValue{
 					log.Int("n", 1),
 					log.String("foo", "bar"),