Preserve previous default versions in v3 (#3748)

Fixes #3424

Before considering the resources marked for removal, if the resource
version was in the previous default version, ensure we include it.

Only fix this for v3 onwards so we don't introduce schema changes now.

Bonus:
- Fix handling of "-beta" versions when converting back from SDK version
to API version.

Stacked on top of #3753

provider/pkg/openapi/discover.go

@@ -170,7 +170,18 @@ func NewVersionResources() VersionResources {
 type ProviderVersionList = map[ProviderName][]ApiVersion
 
 // DefaultVersionLock is an amalgamation of multiple API versions
-type DefaultVersionLock = map[ProviderName]map[DefinitionName]ApiVersion
+type DefaultVersionLock map[ProviderName]map[DefinitionName]ApiVersion
+
+func (lock DefaultVersionLock) IsAtVersion(provider ProviderName, typeName DefinitionName, version ApiVersion) bool {
+	if resources, ok := lock[provider]; ok {
+		if resourceVersion, ok := resources[typeName]; ok {
+			if resourceVersion == version {
+				return true
+			}
+		}
+	}
+	return false
+}
 
 func (v VersionResources) All() map[string]*ResourceSpec {
 	specs := map[string]*ResourceSpec{}

provider/pkg/versioning/gen.go

@@ -41,12 +41,12 @@ func (v VersionMetadata) ShouldInclude(provider string, version *openapi.ApiVers
 		return true
 	}
 	// Keep any resources in the default version lock
-	if resources, ok := v.Lock[provider]; ok {
-		if defaultResourceVersion, ok := resources[typeName]; ok {
-			if defaultResourceVersion == *version {
-				return true
-			}
-		}
+	if v.Lock.IsAtVersion(provider, typeName, *version) {
+		return true
+	}
+	// Keep any resources in the previous version lock for easier migration
+	if v.MajorVersion >= 3 && v.PreviousLock.IsAtVersion(provider, typeName, *version) {
+		return true
 	}
 	// Exclude versions from removed versions
 	if versions, ok := v.RemovedVersions[provider]; ok {
@@ -136,11 +136,12 @@ type VersionSources struct {
 	MajorVersion              int
 	ProviderList              providerlist.ProviderList
 	requiredExplicitResources []string
-	PreviousLock              openapi.DefaultVersionLock
-	RemovedVersions           openapi.ProviderVersionList
-	Spec                      Spec
-	Config                    Curations
-	ConfigPath                string
+	// map[ProviderName]map[DefinitionName]ApiVersion
+	PreviousLock    openapi.DefaultVersionLock
+	RemovedVersions openapi.ProviderVersionList
+	Spec            Spec
+	Config          Curations
+	ConfigPath      string
 	// provider->version->[]resource
 	AllResourcesByVersion ProvidersVersionResources
 	// map[TokenToRemove]TokenReplacedWith