git: add adapters from v1 types to the v2 interfaces

Signed-off-by: Steve Kuznetsov <skuznets@redhat.com>

prow/git/v2/BUILD.bazel

@@ -8,11 +8,16 @@ load(
 go_library(
     name = "go_default_library",
     srcs = [
+        "adapter.go",
         "client_factory.go",
         "interactor.go",
         "publisher.go",
     ],
     importpath = "k8s.io/test-infra/prow/git/v2",
+    deps = [
+        "//prow/git:go_default_library",
+        "//prow/github:go_default_library",
+    ],
 )
 
 filegroup(

prow/git/v2/adapter.go

@@ -0,0 +1,69 @@
+package git
+
+import (
+	"errors"
+
+	"k8s.io/test-infra/prow/git"
+	"k8s.io/test-infra/prow/github"
+)
+
+// ClientFactoryFrom adapts the v1 client to a v2 client
+func ClientFactoryFrom(c *git.Client) ClientFactory {
+	return &clientFactoryAdapter{Client: c}
+}
+
+type clientFactoryAdapter struct {
+	*git.Client
+}
+
+// ClientFromDir creates a client that operates on a repo that has already
+// been cloned to the given directory.
+func (a *clientFactoryAdapter) ClientFromDir(org, repo, dir string) (RepoClient, error) {
+	return nil, errors.New("no ClientFromDir implementation exists in the v1 git client")
+}
+
+// Repo creates a client that operates on a new clone of the repo.
+func (a *clientFactoryAdapter) ClientFor(org, repo string) (RepoClient, error) {
+	r, err := a.Client.Clone(org, repo)
+	return &repoClientAdapter{Repo: r}, err
+}
+
+type repoClientAdapter struct {
+	*git.Repo
+}
+
+func (a *repoClientAdapter) MergeAndCheckout(baseSHA string, mergeStrategy string, headSHAs ...string) error {
+	return a.Repo.MergeAndCheckout(baseSHA, github.PullRequestMergeType(mergeStrategy), headSHAs...)
+}
+
+func (a *repoClientAdapter) MergeWithStrategy(commitlike, mergeStrategy string) (bool, error) {
+	return a.Repo.MergeWithStrategy(commitlike, github.PullRequestMergeType(mergeStrategy))
+}
+
+func (a *repoClientAdapter) Clone(from string) error {
+	return errors.New("no Clone implementation exists in the v1 repo client")
+}
+
+func (a *repoClientAdapter) Commit(title, body string) error {
+	return errors.New("no Commit implementation exists in the v1 repo client")
+}
+
+func (a *repoClientAdapter) ForcePush(branch string) error {
+	return errors.New("no ForcePush implementation exists in the v1 repo client")
+}
+
+func (a *repoClientAdapter) MirrorClone() error {
+	return errors.New("no MirrorClone implementation exists in the v1 repo client")
+}
+
+func (a *repoClientAdapter) Fetch() error {
+	return errors.New("no Fetch implementation exists in the v1 repo client")
+}
+
+func (a *repoClientAdapter) RemoteUpdate() error {
+	return errors.New("no RemoteUpdate implementation exists in the v1 repo client")
+}
+
+func (a *repoClientAdapter) FetchRef(refspec string) error {
+	return errors.New("no FetchRef implementation exists in the v1 repo client")
+}