internal/telemetry: make test event with functions

This will allow us to use the public API to generate the events.
This avoids creating the structs by hand.
It also helps tests the other API.

Change-Id: Ic90cbbaf6fc97c2a3e6a5ff64dccdff0d65ec865
Reviewed-on: https://go-review.googlesource.com/c/tools/+/206885
Run-TryBot: Ian Cottrell <[email protected]>
Reviewed-by: Emmanuel Odeke <[email protected]>
Reviewed-by: Rebecca Stambler <[email protected]>

Author: Ian Cottrell

internal/telemetry/export/ocagent/ocagent_test.go

@@ -5,6 +5,7 @@
 package ocagent
 
 import (
+	"context"
 	"encoding/json"
 	"errors"
 	"reflect"
@@ -17,20 +18,23 @@ import (
 func TestConvert_annotation(t *testing.T) {
 	tests := []struct {
 		name  string
-		event telemetry.Event
+		event func(ctx context.Context) telemetry.Event
 		want  string
 	}{
 		{
-			name: "no tags",
-			want: "null",
+			name:  "no tags",
+			event: func(ctx context.Context) telemetry.Event { return telemetry.Event{} },
+			want:  "null",
 		},
 		{
 			name: "description no error",
-			event: telemetry.Event{
-				Message: "cache miss",
-				Tags: telemetry.TagList{
-					tag.Of("db", "godb"),
-				},
+			event: func(ctx context.Context) telemetry.Event {
+				return telemetry.Event{
+					Message: "cache miss",
+					Tags: telemetry.TagList{
+						tag.Of("db", "godb"),
+					},
+				}
 			},
 			want: `{
   "description": {
@@ -50,12 +54,14 @@ func TestConvert_annotation(t *testing.T) {
 
 		{
 			name: "description and error",
-			event: telemetry.Event{
-				Message: "cache miss",
-				Error:   errors.New("no network connectivity"),
-				Tags: telemetry.TagList{
-					tag.Of("db", "godb"),
-				},
+			event: func(ctx context.Context) telemetry.Event {
+				return telemetry.Event{
+					Message: "cache miss",
+					Error:   errors.New("no network connectivity"),
+					Tags: telemetry.TagList{
+						tag.Of("db", "godb"),
+					},
+				}
 			},
 			want: `{
   "description": {
@@ -79,11 +85,13 @@ func TestConvert_annotation(t *testing.T) {
 		},
 		{
 			name: "no description, but error",
-			event: telemetry.Event{
-				Error: errors.New("no network connectivity"),
-				Tags: telemetry.TagList{
-					tag.Of("db", "godb"),
-				},
+			event: func(ctx context.Context) telemetry.Event {
+				return telemetry.Event{
+					Error: errors.New("no network connectivity"),
+					Tags: telemetry.TagList{
+						tag.Of("db", "godb"),
+					},
+				}
 			},
 			want: `{
   "description": {
@@ -102,30 +110,32 @@ func TestConvert_annotation(t *testing.T) {
 		},
 		{
 			name: "enumerate all attribute types",
-			event: telemetry.Event{
-				Message: "cache miss",
-				Tags: telemetry.TagList{
-					tag.Of("db", "godb"),
+			event: func(ctx context.Context) telemetry.Event {
+				return telemetry.Event{
+					Message: "cache miss",
+					Tags: telemetry.TagList{
+						tag.Of("db", "godb"),
 
-					tag.Of("age", 0.456), // Constant converted into "float64"
-					tag.Of("ttl", float32(5000)),
-					tag.Of("expiry_ms", float64(1e3)),
+						tag.Of("age", 0.456), // Constant converted into "float64"
+						tag.Of("ttl", float32(5000)),
+						tag.Of("expiry_ms", float64(1e3)),
 
-					tag.Of("retry", false),
-					tag.Of("stale", true),
+						tag.Of("retry", false),
+						tag.Of("stale", true),
 
-					tag.Of("max", 0x7fff), // Constant converted into "int"
-					tag.Of("opcode", int8(0x7e)),
-					tag.Of("base", int16(1<<9)),
-					tag.Of("checksum", int32(0x11f7e294)),
-					tag.Of("mode", int64(0644)),
+						tag.Of("max", 0x7fff), // Constant converted into "int"
+						tag.Of("opcode", int8(0x7e)),
+						tag.Of("base", int16(1<<9)),
+						tag.Of("checksum", int32(0x11f7e294)),
+						tag.Of("mode", int64(0644)),
 
-					tag.Of("min", uint(1)),
-					tag.Of("mix", uint8(44)),
-					tag.Of("port", uint16(55678)),
-					tag.Of("min_hops", uint32(1<<9)),
-					tag.Of("max_hops", uint64(0xffffff)),
-				},
+						tag.Of("min", uint(1)),
+						tag.Of("mix", uint8(44)),
+						tag.Of("port", uint16(55678)),
+						tag.Of("min_hops", uint32(1<<9)),
+						tag.Of("max_hops", uint64(0xffffff)),
+					},
+				}
 			},
 			want: `{
   "description": {
@@ -186,10 +196,10 @@ func TestConvert_annotation(t *testing.T) {
 }`,
 		},
 	}
-
+	ctx := context.TODO()
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got := marshaled(convertAnnotation(tt.event))
+			got := marshaled(convertAnnotation(tt.event(ctx)))
 			if !reflect.DeepEqual(got, tt.want) {
 				t.Fatalf("Got:\n%s\nWant:\n%s", got, tt.want)
 			}