client-gen tag shortcomings when newline is omitted

[antoineco]

client-gen does not generate the content of typed/<group>/<version>/<group>_client.go / typed/<group>/<version>/generated_expansion.go when there is no new line between the // +genclient tag and the next struct.

How to reproduce:

works

// +genclient
// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object

type Foo struct {

fails

// +genclient
// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
type Foo struct {

See also:

https://kubernetes.slack.com/archives/C0EG7JC6T/p1507887214000200

/kind bug
/sig api-machinery

[antoineco]

Full diff of what happened after I added the new line:

diff --git a/pkg/apis/hcs/v1alpha1/types.go b/pkg/apis/hcs/v1alpha1/types.go
index 5a8df93..4be5682 100644
--- a/pkg/apis/hcs/v1alpha1/types.go
+++ b/pkg/apis/hcs/v1alpha1/types.go
@@ -7,6 +7,7 @@ import (
 // MyCustomResource is my custom resource.
 // +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
 // +genclient
+
 type MyCustomResource struct {
        metav1.TypeMeta   `json:",inline"`
        metav1.ObjectMeta `json:"metadata,omitempty"`
diff --git a/pkg/client/clientset_generated/internalclientset/typed/hcs/v1alpha1/fake/fake_hcs_client.go b/pkg/client/clientset_generated/internalclientset/typed/hcs/v1alpha1/fake/fake_hcs_client.go
index ba9fa5a..350d9e8 100644
--- a/pkg/client/clientset_generated/internalclientset/typed/hcs/v1alpha1/fake/fake_hcs_client.go
+++ b/pkg/client/clientset_generated/internalclientset/typed/hcs/v1alpha1/fake/fake_hcs_client.go
@@ -2,4 +2,21 @@ package fake

 import (
        v1alpha1 "my.repo/pkg/client/clientset_generated/internalclientset/typed/hcs/v1alpha1"
+       rest "k8s.io/client-go/rest"
+       testing "k8s.io/client-go/testing"
 )
+
+type FakeHcsV1alpha1 struct {
+       *testing.Fake
+}
+
+func (c *FakeHcsV1alpha1) MyCustomResources(namespace string) v1alpha1.MyCustomResourceInterface {
+       return &FakeMyCustomResources{c, namespace}
+}
+
+// RESTClient returns a RESTClient that is used to communicate
+// with API server by this client implementation.
+func (c *FakeHcsV1alpha1) RESTClient() rest.Interface {
+       var ret *rest.RESTClient
+       return ret
+}
diff --git a/pkg/client/clientset_generated/internalclientset/typed/hcs/v1alpha1/generated_expansion.go b/pkg/client/clientset_generated/internalclientset/typed/hcs/v1alpha1/generated_expansion.go
index 1c26788..a12c950 100644
--- a/pkg/client/clientset_generated/internalclientset/typed/hcs/v1alpha1/generated_expansion.go
+++ b/pkg/client/clientset_generated/internalclientset/typed/hcs/v1alpha1/generated_expansion.go
@@ -1 +1,3 @@
 package v1alpha1
+
+type MyCustomResourceExpansion interface{}
diff --git a/pkg/client/clientset_generated/internalclientset/typed/hcs/v1alpha1/hcs_client.go b/pkg/client/clientset_generated/internalclientset/typed/hcs/v1alpha1/hcs_client.go
index e8cfb42..af96279 100644
--- a/pkg/client/clientset_generated/internalclientset/typed/hcs/v1alpha1/hcs_client.go
+++ b/pkg/client/clientset_generated/internalclientset/typed/hcs/v1alpha1/hcs_client.go
@@ -1,5 +1,72 @@
 package v1alpha1

 import (
+       v1alpha1 "my.repo/pkg/apis/hcs/v1alpha1"
        "my.repo/pkg/client/clientset_generated/internalclientset/scheme"
+       serializer "k8s.io/apimachinery/pkg/runtime/serializer"
+       rest "k8s.io/client-go/rest"
 )
+
+type HcsV1alpha1Interface interface {
+       RESTClient() rest.Interface
+       MyCustomResourcesGetter
+}
+
+// HcsV1alpha1Client is used to interact with features provided by the hcs group.
+type HcsV1alpha1Client struct {
+       restClient rest.Interface
+}
+
+func (c *HcsV1alpha1Client) MyCustomResources(namespace string) MyCustomResourceInterface {
+       return newMyCustomResources(c, namespace)
+}
+
+// NewForConfig creates a new HcsV1alpha1Client for the given config.
+func NewForConfig(c *rest.Config) (*HcsV1alpha1Client, error) {
+       config := *c
+       if err := setConfigDefaults(&config); err != nil {
+               return nil, err
+       }
+       client, err := rest.RESTClientFor(&config)
+       if err != nil {
+               return nil, err
+       }
+       return &HcsV1alpha1Client{client}, nil
+}
+
+// NewForConfigOrDie creates a new HcsV1alpha1Client for the given config and
+// panics if there is an error in the config.
+func NewForConfigOrDie(c *rest.Config) *HcsV1alpha1Client {
+       client, err := NewForConfig(c)
+       if err != nil {
+               panic(err)
+       }
+       return client
+}
+
+// New creates a new HcsV1alpha1Client for the given RESTClient.
+func New(c rest.Interface) *HcsV1alpha1Client {
+       return &HcsV1alpha1Client{c}
+}
+
+func setConfigDefaults(config *rest.Config) error {
+       gv := v1alpha1.SchemeGroupVersion
+       config.GroupVersion = &gv
+       config.APIPath = "/apis"
+       config.NegotiatedSerializer = serializer.DirectCodecFactory{CodecFactory: scheme.Codecs}
+
+       if config.UserAgent == "" {
+               config.UserAgent = rest.DefaultKubernetesUserAgent()
+       }
+
+       return nil
+}
+
+// RESTClient returns a RESTClient that is used to communicate
+// with API server by this client implementation.
+func (c *HcsV1alpha1Client) RESTClient() rest.Interface {
+       if c == nil {
+               return nil
+       }
+       return c.restClient
+}

[sttts]

Other tags must not have newlines #53579. We should remove this distinction.

[mbohlool]

cc @caesarxuchao