From 70566f4bd42964315e7afd0cd1e6820ef9fd4564 Mon Sep 17 00:00:00 2001
From: David Gageot <david@gageot.net>
Date: Fri, 5 Oct 2018 14:52:59 +0200
Subject: [PATCH] Add a test to check version upgrades

Each version should upgrade to the next version.
This test is an additional safety net when adding
a new version.

Signed-off-by: David Gageot <david@gageot.net>
---
 pkg/skaffold/schema/versions.go      | 38 ++++++++++++++++++++--------
 pkg/skaffold/schema/versions_test.go | 23 +++++++++++++++++
 2 files changed, 51 insertions(+), 10 deletions(-)

diff --git a/pkg/skaffold/schema/versions.go b/pkg/skaffold/schema/versions.go
index 0a414c49be0..4ab44a79028 100644
--- a/pkg/skaffold/schema/versions.go
+++ b/pkg/skaffold/schema/versions.go
@@ -19,7 +19,7 @@ package schema
 import (
 	"github.com/pkg/errors"
 
-	version "github.com/GoogleContainerTools/skaffold/pkg/skaffold/apiversion"
+	apiversion "github.com/GoogleContainerTools/skaffold/pkg/skaffold/apiversion"
 	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/schema/latest"
 	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/schema/util"
 	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/schema/v1alpha1"
@@ -34,11 +34,29 @@ type APIVersion struct {
 	Version string `yaml:"apiVersion"`
 }
 
-var schemaVersions = map[string]func() util.VersionedConfig{
-	v1alpha1.Version: v1alpha1.NewSkaffoldPipeline,
-	v1alpha2.Version: v1alpha2.NewSkaffoldPipeline,
-	v1alpha3.Version: v1alpha3.NewSkaffoldPipeline,
-	latest.Version:   latest.NewSkaffoldPipeline,
+var schemaVersions = versions{
+	{v1alpha1.Version, v1alpha1.NewSkaffoldPipeline},
+	{v1alpha2.Version, v1alpha2.NewSkaffoldPipeline},
+	{v1alpha3.Version, v1alpha3.NewSkaffoldPipeline},
+	{latest.Version, latest.NewSkaffoldPipeline},
+}
+
+type version struct {
+	apiVersion string
+	factory    func() util.VersionedConfig
+}
+
+type versions []version
+
+// Find search the constructor for a given api version.
+func (v *versions) Find(apiVersion string) (func() util.VersionedConfig, bool) {
+	for _, version := range *v {
+		if version.apiVersion == apiVersion {
+			return version.factory, true
+		}
+	}
+
+	return nil, false
 }
 
 // ParseConfig reads a configuration file.
@@ -53,7 +71,7 @@ func ParseConfig(filename string, applyDefaults bool) (util.VersionedConfig, err
 		return nil, errors.Wrap(err, "parsing api version")
 	}
 
-	factory, present := schemaVersions[apiVersion.Version]
+	factory, present := schemaVersions.Find(apiVersion.Version)
 	if !present {
 		return nil, errors.Wrapf(err, "unknown version: %s", apiVersion.Version)
 	}
@@ -72,16 +90,16 @@ func ParseConfig(filename string, applyDefaults bool) (util.VersionedConfig, err
 
 // CheckVersionIsLatest checks that a given version is the most recent.
 func CheckVersionIsLatest(apiVersion string) error {
-	parsedVersion, err := version.Parse(apiVersion)
+	parsedVersion, err := apiversion.Parse(apiVersion)
 	if err != nil {
 		return errors.Wrap(err, "parsing api version")
 	}
 
-	if parsedVersion.LT(version.MustParse(latest.Version)) {
+	if parsedVersion.LT(apiversion.MustParse(latest.Version)) {
 		return errors.New("config version out of date: run `skaffold fix`")
 	}
 
-	if parsedVersion.GT(version.MustParse(latest.Version)) {
+	if parsedVersion.GT(apiversion.MustParse(latest.Version)) {
 		return errors.New("config version is too new for this version of skaffold: upgrade skaffold")
 	}
 
diff --git a/pkg/skaffold/schema/versions_test.go b/pkg/skaffold/schema/versions_test.go
index ccfefd3bae6..cdaedf399a3 100644
--- a/pkg/skaffold/schema/versions_test.go
+++ b/pkg/skaffold/schema/versions_test.go
@@ -330,3 +330,26 @@ func TestCheckVersionIsLatest(t *testing.T) {
 		})
 	}
 }
+
+func TestUpgradeToNextVersion(t *testing.T) {
+	for i, schemaVersion := range schemaVersions[0 : len(schemaVersions)-2] {
+		from := schemaVersion
+		to := schemaVersions[i+1]
+		description := fmt.Sprintf("Upgrade from %s to %s", from.apiVersion, to.apiVersion)
+
+		t.Run(description, func(t *testing.T) {
+			factory, _ := schemaVersions.Find(from.apiVersion)
+			newer, err := factory().Upgrade()
+
+			testutil.CheckErrorAndDeepEqual(t, false, err, to.apiVersion, newer.GetVersion())
+		})
+	}
+}
+
+func TestCantUpgradeFromLastestVersion(t *testing.T) {
+	factory, present := schemaVersions.Find(latest.Version)
+	testutil.CheckDeepEqual(t, true, present)
+
+	_, err := factory().Upgrade()
+	testutil.CheckError(t, true, err)
+}