add unit tests

instrumentation/github.com/aws/aws-lambda-go/otellambda/example/go.sum

@@ -68,6 +68,7 @@ go.opentelemetry.io/otel/metric v1.21.0 h1:tlYWfeo+Bocx5kLEloTjbcDwBuELRrIFxwdQ3
 go.opentelemetry.io/otel/metric v1.21.0/go.mod h1:o1p3CA8nNHW8j5yuQLdc1eeqEaPfzug24uvsyIEJRWM=
 go.opentelemetry.io/otel/sdk v1.21.0 h1:FTt8qirL1EysG6sTQRZ5TokkU8d0ugCj8htOgThZXQ8=
 go.opentelemetry.io/otel/sdk v1.21.0/go.mod h1:Nna6Yv7PWTdgJHVRD9hIYywQBRx7pbox6nwBnZIxl/E=
+go.opentelemetry.io/otel/sdk/metric v1.21.0 h1:smhI5oD714d6jHE6Tie36fPx4WDFIg+Y6RfAY4ICcR0=
 go.opentelemetry.io/otel/trace v1.21.0 h1:WD9i5gzvoUPuXIXH24ZNBudiarZDKuekPqi/E8fpfLc=
 go.opentelemetry.io/otel/trace v1.21.0/go.mod h1:LGbsEB0f9LGjN+OZaQQ26sohbOmiMR+BaslueVtS/qQ=
 golang.org/x/sys v0.14.0 h1:Vz7Qs629MkJkGyHxUlRHizWJRG2j8fbQKjELVSNhy7Q=

instrumentation/net/http/otelhttp/go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/stretchr/testify v1.8.4
 	go.opentelemetry.io/otel v1.21.0
 	go.opentelemetry.io/otel/metric v1.21.0
+	go.opentelemetry.io/otel/sdk/metric v1.21.0
 	go.opentelemetry.io/otel/trace v1.21.0
 )
 
@@ -15,5 +16,7 @@ require (
 	github.com/go-logr/logr v1.3.0 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	go.opentelemetry.io/otel/sdk v1.21.0 // indirect
+	golang.org/x/sys v0.14.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

instrumentation/net/http/otelhttp/go.sum

@@ -16,8 +16,14 @@ go.opentelemetry.io/otel v1.21.0 h1:hzLeKBZEL7Okw2mGzZ0cc4k/A7Fta0uoPgaJCr8fsFc=
 go.opentelemetry.io/otel v1.21.0/go.mod h1:QZzNPQPm1zLX4gZK4cMi+71eaorMSGT3A4znnUvNNEo=
 go.opentelemetry.io/otel/metric v1.21.0 h1:tlYWfeo+Bocx5kLEloTjbcDwBuELRrIFxwdQ36PlJu4=
 go.opentelemetry.io/otel/metric v1.21.0/go.mod h1:o1p3CA8nNHW8j5yuQLdc1eeqEaPfzug24uvsyIEJRWM=
+go.opentelemetry.io/otel/sdk v1.21.0 h1:FTt8qirL1EysG6sTQRZ5TokkU8d0ugCj8htOgThZXQ8=
+go.opentelemetry.io/otel/sdk v1.21.0/go.mod h1:Nna6Yv7PWTdgJHVRD9hIYywQBRx7pbox6nwBnZIxl/E=
+go.opentelemetry.io/otel/sdk/metric v1.21.0 h1:smhI5oD714d6jHE6Tie36fPx4WDFIg+Y6RfAY4ICcR0=
+go.opentelemetry.io/otel/sdk/metric v1.21.0/go.mod h1:FJ8RAsoPGv/wYMgBdUJXOm+6pzFY3YdljnXtv1SBE8Q=
 go.opentelemetry.io/otel/trace v1.21.0 h1:WD9i5gzvoUPuXIXH24ZNBudiarZDKuekPqi/E8fpfLc=
 go.opentelemetry.io/otel/trace v1.21.0/go.mod h1:LGbsEB0f9LGjN+OZaQQ26sohbOmiMR+BaslueVtS/qQ=
+golang.org/x/sys v0.14.0 h1:Vz7Qs629MkJkGyHxUlRHizWJRG2j8fbQKjELVSNhy7Q=
+golang.org/x/sys v0.14.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

instrumentation/net/http/otelhttp/internal/semconvutil/httpconv.go

@@ -52,10 +52,9 @@ func HTTPClientRequest(req *http.Request) []attribute.KeyValue {
 }
 
 // HTTPClientRequestMetrics returns metric attributes for an HTTP request made by a client.
-// The following attributes are always returned: "http.flavor",
-// "http.method", "net.peer.name". The following attributes are returned if the
-// related values are defined in req: "http.url", "net.peer.port", "http.user_agent",
-// "enduser.id".
+// The following attributes are always returned: "http.method", "net.peer.name".
+// The following attributes are returned if the
+// related values are defined in req: "net.peer.port".
 func HTTPClientRequestMetrics(req *http.Request) []attribute.KeyValue {
 	return hc.ClientRequestMetrics(req)
 }
@@ -296,8 +295,8 @@ func (c *httpConv) ClientRequest(req *http.Request) []attribute.KeyValue {
 }
 
 // ClientRequestMetrics returns metric attributes for an HTTP request made by a client. The
-// following attributes are always returned: "http.method",
-// "net.peer.name". The following attributes are returned if the related values
+// following attributes are always returned: "http.method", "net.peer.name".
+// The following attributes are returned if the related values
 // are defined in req: "net.peer.port".
 func (c *httpConv) ClientRequestMetrics(req *http.Request) []attribute.KeyValue {
 	/* The following semantic conventions are returned if present:

instrumentation/net/http/otelhttp/transport_test.go

@@ -18,9 +18,16 @@ import (
 	"bytes"
 	"context"
 	"errors"
+	"fmt"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/sdk/instrumentation"
+	"go.opentelemetry.io/otel/sdk/metric/metricdata/metricdatatest"
+	semconv "go.opentelemetry.io/otel/semconv/v1.20.0"
 	"io"
+	"net"
 	"net/http"
 	"net/http/httptest"
+	"strconv"
 	"strings"
 	"testing"
 
@@ -30,6 +37,9 @@ import (
 	"go.opentelemetry.io/otel/codes"
 	"go.opentelemetry.io/otel/propagation"
 	"go.opentelemetry.io/otel/trace"
+
+	"go.opentelemetry.io/otel/sdk/metric"
+	"go.opentelemetry.io/otel/sdk/metric/metricdata"
 )
 
 func TestTransportFormatter(t *testing.T) {
@@ -432,3 +442,121 @@ func TestTransportOriginRequestNotModify(t *testing.T) {
 
 	assert.Equal(t, expectedRequest, r)
 }
+
+func TestTransportMetrics(t *testing.T) {
+	reader := metric.NewManualReader()
+	meterProvider := metric.NewMeterProvider(metric.WithReader(reader))
+
+	responseBody := []byte("Hello, world!")
+
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+		if _, err := w.Write(responseBody); err != nil {
+			t.Fatal(err)
+		}
+	}))
+	defer ts.Close()
+
+	requestBody := []byte("john")
+	r, err := http.NewRequest(http.MethodGet, ts.URL, bytes.NewReader(requestBody))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	tr := NewTransport(
+		http.DefaultTransport,
+		WithMeterProvider(meterProvider),
+	)
+
+	c := http.Client{Transport: tr}
+	res, err := c.Do(r)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Must read the body or else we won't get response metrics
+	bodyBytes, err := io.ReadAll(res.Body)
+	if err != nil {
+		t.Fatal(err)
+	}
+	require.Len(t, bodyBytes, 13)
+	require.NoError(t, res.Body.Close())
+
+	host, portStr, _ := net.SplitHostPort(r.Host)
+	if host == "" {
+		host = "127.0.0.1"
+	}
+	port, err := strconv.Atoi(portStr)
+	if err != nil {
+		port = 0
+	}
+
+	rm := metricdata.ResourceMetrics{}
+	err = reader.Collect(context.Background(), &rm)
+	require.NoError(t, err)
+	require.Len(t, rm.ScopeMetrics, 1)
+	attrs := attribute.NewSet(
+		semconv.NetPeerName(host),
+		semconv.NetPeerPort(port),
+		semconv.HTTPMethod("GET"),
+		semconv.HTTPStatusCode(200),
+	)
+	assertClientScopeMetrics(t, rm.ScopeMetrics[0], attrs)
+}
+
+func assertClientScopeMetrics(t *testing.T, sm metricdata.ScopeMetrics, attrs attribute.Set) {
+
+	assert.Equal(t, instrumentation.Scope{
+		Name:    "go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp",
+		Version: Version(),
+	}, sm.Scope)
+
+	require.Len(t, sm.Metrics, 3)
+
+	want := metricdata.Metrics{
+		Name: "http.client.request_content_length",
+		Data: metricdata.Sum[int64]{
+			DataPoints:  []metricdata.DataPoint[int64]{{Attributes: attrs, Value: 4}},
+			Temporality: metricdata.CumulativeTemporality,
+			IsMonotonic: true,
+		},
+		Description: "Measures the size of HTTP request content length (uncompressed)",
+		Unit:        "By",
+	}
+	metricdatatest.AssertEqual(t, want, sm.Metrics[0], metricdatatest.IgnoreTimestamp())
+
+	want = metricdata.Metrics{
+		Name: "http.client.response_content_length",
+		Data: metricdata.Sum[int64]{
+			DataPoints:  []metricdata.DataPoint[int64]{{Attributes: attrs, Value: 13}},
+			Temporality: metricdata.CumulativeTemporality,
+			IsMonotonic: true,
+		},
+		Description: "Measures the size of HTTP response content length (uncompressed)",
+		Unit:        "By",
+	}
+	metricdatatest.AssertEqual(t, want, sm.Metrics[1], metricdatatest.IgnoreTimestamp())
+
+	dur := sm.Metrics[2]
+	assert.Equal(t, "http.client.duration", dur.Name)
+	require.IsType(t, dur.Data, metricdata.Histogram[float64]{})
+	hist := dur.Data.(metricdata.Histogram[float64])
+	assert.Equal(t, metricdata.CumulativeTemporality, hist.Temporality)
+	require.Len(t, hist.DataPoints, 1)
+	dPt := hist.DataPoints[0]
+	assert.Equal(t, attrs, dPt.Attributes, "attributes")
+	assert.Equal(t, uint64(1), dPt.Count, "count")
+	assert.Equal(t, []float64{0, 5, 10, 25, 50, 75, 100, 250, 500, 750, 1000, 2500, 5000, 7500, 10000}, dPt.Bounds, "bounds")
+
+	t.Log(fmt.Sprintf("%+v", dPt.BucketCounts))
+
+	// Duration value is not deterministic because the code does not support a pluggable clock.
+	// So just value that one of the buckets has been incremented.
+	bucketSum := uint64(0)
+	for _, bucketCount := range dPt.BucketCounts {
+		bucketSum += bucketCount
+	}
+
+	require.Equal(t, uint64(1), bucketSum)
+
+}