skip downgrade test when only one snapshot version is available (#3293)

* make teat work with only one snapshot version

It fixes TestStandaloneUpgradeToSpecificSnapshotBuild to work is there is only one snapshot build available.

* .

* .

(cherry picked from commit 22c276d)

pkg/testing/tools/artifacts_api.go

@@ -23,7 +23,7 @@ const (
 	artifactsAPIV1VersionsEndpoint      = "v1/versions/"
 	artifactsAPIV1VersionBuildsEndpoint = "v1/versions/%s/builds/"
 	artifactAPIV1BuildDetailsEndpoint   = "v1/versions/%s/builds/%s"
-	//artifactAPIV1SearchVersionPackage = "v1/search/%s/%s"
+	// artifactAPIV1SearchVersionPackage = "v1/search/%s/%s"
 )
 
 var (
@@ -275,8 +275,9 @@ func GetLatestSnapshotVersion(ctx context.Context, log logger, aac *ArtifactAPIC
 		return nil, ErrSnapshotVersionsEmpty
 	}
 
-	// normally the output of the versions returned by artifact API is already sorted in ascending order,
-	// if we want to sort in descending order we could use
+	// normally the output of the versions returned by artifact API is already
+	// sorted in ascending order.If we want to sort in descending order we need
+	// to pass a sort.Reverse to sort.Sort.
 	sort.Sort(sort.Reverse(sortedParsedVersions))
 
 	var latestSnapshotVersion *version.ParsedSemVer

testing/integration/upgrade_test.go

@@ -261,7 +261,7 @@ func TestStandaloneUpgradeWithGPGFallback(t *testing.T) {
 	testStandaloneUpgrade(ctx, t, agentFixture, parsedVersion, toVersion, "", false, false, true, customPGP)
 }
 
-func TestStandaloneUpgradeToSpecificSnapshotBuild(t *testing.T) {
+func TestStandaloneDowngradeToPreviousSnapshotBuild(t *testing.T) {
 	define.Require(t, define.Requirements{
 		Local: false, // requires Agent installation
 		Sudo:  true,  // requires Agent installation
@@ -273,7 +273,6 @@ func TestStandaloneUpgradeToSpecificSnapshotBuild(t *testing.T) {
 		t.Skipf("Version %s is lower than min version %s", define.Version(), minVersion)
 	}
 
-	// prepare the agent fixture
 	agentFixture, err := define.NewFixture(t, define.Version())
 	require.NoError(t, err)
 
@@ -293,10 +292,12 @@ func TestStandaloneUpgradeToSpecificSnapshotBuild(t *testing.T) {
 	// get all the builds of the snapshot version (need to pass x.y.z-SNAPSHOT format)
 	builds, err := aac.GetBuildsForVersion(ctx, latestSnapshotVersion.VersionWithPrerelease())
 	require.NoError(t, err)
-	// TODO if we don't have at least 2 builds, select the next older snapshot build
-	require.Greater(t, len(builds.Builds), 1)
 
-	// take the penultimate build of the snapshot (the builds are ordered from most to least recent)
+	if len(builds.Builds) < 2 {
+		t.Skip("there is only one SNAPSHOT version available, " +
+			"the test requires at least 2 so it can downgrade to the previous" +
+			"SNAPSHOT")
+	}
 	upgradeVersionString := builds.Builds[1]
 
 	t.Logf("Targeting build %q of version %q", upgradeVersionString, latestSnapshotVersion)