internal/lsp: change tests to use the main exporter

Now the tests are at a high enough level, we can
switch them to using the full exporter by bulding
a fake http client to bind it to. This lets us
use the true public interface and also excercise
more of the functionality in the tests.
With this we are now ready to replace the entire
implementation safely.

Change-Id: Ifdbf6230de3ec7c7c5381c840b135cb7a0bc1e55
Reviewed-on: https://go-review.googlesource.com/c/tools/+/209161
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>

internal/telemetry/export/ocagent/metrics_test.go

@@ -1,11 +1,11 @@
 package ocagent_test
 
 import (
+	"context"
 	"testing"
 	"time"
 
 	"golang.org/x/tools/internal/telemetry"
-	"golang.org/x/tools/internal/telemetry/export/ocagent"
 	"golang.org/x/tools/internal/telemetry/metric"
 )
 
@@ -312,12 +312,12 @@ func TestEncodeMetric(t *testing.T) {
 		},
 	}
 
+	ctx := context.TODO()
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got, err := ocagent.EncodeMetric(cfg, tt.data)
-			if err != nil {
-				t.Fatal(err)
-			}
+			exporter.Metric(ctx, tt.data)
+			exporter.Flush()
+			got := sent.get("/v1/metrics")
 			checkJSON(t, got, []byte(tt.want))
 		})
 	}

internal/telemetry/export/ocagent/ocagent.go

@@ -149,20 +149,6 @@ func (cfg *Config) buildNode() *wire.Node {
 	}
 }
 
-func EncodeSpan(cfg Config, span *telemetry.Span) ([]byte, error) {
-	return json.Marshal(&wire.ExportTraceServiceRequest{
-		Node:  cfg.buildNode(),
-		Spans: []*wire.Span{convertSpan(span)},
-	})
-}
-
-func EncodeMetric(cfg Config, m telemetry.MetricData) ([]byte, error) {
-	return json.Marshal(&wire.ExportMetricsServiceRequest{
-		Node:    cfg.buildNode(),
-		Metrics: []*wire.Metric{convertMetric(m, cfg.Start)},
-	})
-}
-
 func (e *exporter) send(endpoint string, message interface{}) {
 	blob, err := json.Marshal(message)
 	if err != nil {

internal/telemetry/export/ocagent/ocagent_test.go

@@ -9,27 +9,36 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"sync"
 	"testing"
 	"time"
 
 	"golang.org/x/tools/internal/telemetry"
+	"golang.org/x/tools/internal/telemetry/export"
 	"golang.org/x/tools/internal/telemetry/export/ocagent"
 	"golang.org/x/tools/internal/telemetry/tag"
 )
 
 var (
-	cfg = ocagent.Config{
-		Host:    "tester",
-		Process: 1,
-		Service: "ocagent-tests",
-	}
-	start time.Time
-	at    time.Time
-	end   time.Time
+	exporter export.Exporter
+	sent     fakeSender
+	start    time.Time
+	at       time.Time
+	end      time.Time
 )
 
 func init() {
+	cfg := ocagent.Config{
+		Host:    "tester",
+		Process: 1,
+		Service: "ocagent-tests",
+		Client:  &http.Client{Transport: &sent},
+	}
 	cfg.Start, _ = time.Parse(time.RFC3339Nano, "1970-01-01T00:00:00Z")
+	exporter = ocagent.Connect(&cfg)
 }
 
 const testNodeStr = `{
@@ -267,10 +276,10 @@ func TestEvents(t *testing.T) {
 				Finish: end,
 				Events: []telemetry.Event{tt.event(ctx)},
 			}
-			got, err := ocagent.EncodeSpan(cfg, span)
-			if err != nil {
-				t.Fatal(err)
-			}
+			exporter.StartSpan(ctx, span)
+			exporter.FinishSpan(ctx, span)
+			exporter.Flush()
+			got := sent.get("/v1/trace")
 			checkJSON(t, got, []byte(tt.want))
 		})
 	}
@@ -291,3 +300,42 @@ func checkJSON(t *testing.T, got, want []byte) {
 		t.Fatalf("Got:\n%s\nWant:\n%s", g, w)
 	}
 }
+
+type fakeSender struct {
+	mu   sync.Mutex
+	data map[string][]byte
+}
+
+func (s *fakeSender) get(route string) []byte {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	data, found := s.data[route]
+	if found {
+		delete(s.data, route)
+	}
+	return data
+}
+
+func (s *fakeSender) RoundTrip(req *http.Request) (*http.Response, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if s.data == nil {
+		s.data = make(map[string][]byte)
+	}
+	data, err := ioutil.ReadAll(req.Body)
+	if err != nil {
+		return nil, err
+	}
+	path := req.URL.EscapedPath()
+	if _, found := s.data[path]; found {
+		return nil, fmt.Errorf("duplicate delivery to %v", path)
+	}
+	s.data[path] = data
+	return &http.Response{
+		Status:     "200 OK",
+		StatusCode: 200,
+		Proto:      "HTTP/1.0",
+		ProtoMajor: 1,
+		ProtoMinor: 0,
+	}, nil
+}