Improved test reliability

go.mod

@@ -24,6 +24,7 @@ require (
 	github.com/Microsoft/hcsshim v0.9.4 // indirect
 	github.com/ProtonMail/go-crypto v0.0.0-20210428141323-04723f9f07d7 // indirect
 	github.com/acomagu/bufpipe v1.0.3 // indirect
+	github.com/avast/retry-go v3.0.0+incompatible // indirect
 	github.com/cenkalti/backoff/v4 v4.3.0 // indirect
 	github.com/containerd/cgroups v1.0.4 // indirect
 	github.com/containerd/containerd v1.6.8 // indirect

go.sum

@@ -115,6 +115,8 @@ github.com/armon/go-radix v0.0.0-20180808171621-7fddfc383310/go.mod h1:ufUuZ+zHj
 github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5 h1:0CwZNZbxp69SHPdPJAN/hZIm0C4OItdklCFmMRWYpio=
 github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5/go.mod h1:wHh0iHkYZB8zMSxRWpUBQtwG5a7fFgvEO+odwuTv2gs=
 github.com/asaskevich/govalidator v0.0.0-20190424111038-f61b66f89f4a/go.mod h1:lB+ZfQJz7igIIfQNfa7Ml4HSf2uFQQRzpGGRXenZAgY=
+github.com/avast/retry-go v3.0.0+incompatible h1:4SOWQ7Qs+oroOTQOYnAHqelpCO0biHSxpiH9JdtuBj0=
+github.com/avast/retry-go v3.0.0+incompatible/go.mod h1:XtSnn+n/sHqQIpZ10K1qAevBhOOCWBLXXy3hyiqqBrY=
 github.com/aws/aws-sdk-go v1.15.11/go.mod h1:mFuSZ37Z9YOHbQEwBWztmVzqXrEkub65tZoCYDt7FT0=
 github.com/benbjohnson/clock v1.0.3/go.mod h1:bGMdMPoPVvcYyt1gHDf4J2KE153Yf9BuiUKYMaxlTDM=
 github.com/beorn7/perks v0.0.0-20160804104726-4c0e84591b9a/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=

main_test.go

@@ -9,8 +9,9 @@ import (
 	"path"
 	"strings"
 	"testing"
-	"time"
 
+	"github.com/avast/retry-go"
+	"github.com/docker/go-connections/nat"
 	"github.com/stretchr/testify/assert"
 	"github.com/testcontainers/testcontainers-go"
 )
@@ -212,9 +213,17 @@ func Test_Main_SampleXML(t *testing.T) {
 		t.Error(err)
 	}
 
-	collectorPort, err := otelCollector.MappedPort(ctx, "4317/tcp")
+	var collectorPort nat.Port
+	err = retry.Do(func() error {
+		collectorPort, err = otelCollector.MappedPort(ctx, "4317/tcp")
+		if err != nil {
+			return err
+		}
+
+		return nil
+	})
 	if err != nil {
-		t.Errorf("could not get mapped port for otel-collector: %v", err)
+		t.Errorf("could not get the collector port: %s", err)
 	}
 
 	os.Setenv(exporterEndpointKey, "http://localhost:"+collectorPort.Port())
@@ -251,25 +260,31 @@ func Test_Main_SampleXML(t *testing.T) {
 		t.Error()
 	}
 
-	// TODO: retry until the file is written by the otel-exporter
-	time.Sleep(time.Second * 30)
-
-	// assert using the generated file
-	jsonBytes, err := os.ReadFile(reportFilePath)
-	if err != nil {
-		t.Error(err)
-	}
-
 	// merge both JSON files
 	// 1. get the spans and metrics JSONs, they are separated by \n
 	// 2. remote white spaces
 	// 3. unmarshal each resource separately
 	// 4. assign each resource to the test report struct
-	content := string(jsonBytes)
 
-	jsons := strings.Split(strings.TrimSpace(content), "\n")
-	if len(jsons) != 2 {
-		t.Errorf("expected 2 JSONs, got %d - %s", len(jsons), jsons)
+	var jsons []string
+	err = retry.Do(func() error {
+		// assert using the generated file
+		jsonBytes, err := os.ReadFile(reportFilePath)
+		if err != nil {
+			t.Error(err)
+		}
+
+		content := string(jsonBytes)
+
+		jsons = strings.Split(strings.TrimSpace(content), "\n")
+		if len(jsons) != 2 {
+			return fmt.Errorf("expected 2 JSONs, got %d - %s", len(jsons), jsons)
+		}
+
+		return nil
+	})
+	if err != nil {
+		t.Errorf("error while waiting for collector output: %s", err)
 	}
 
 	jsonSpans := ""