Merge pull request #56099 from caesarxuchao/fix-client-gen-0-types

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Fix client-gen for groups that no types requiring clients

If the group has no type with the `+genClient` tag, the group client is generated multiple times because the `Filter` function always returns true, resulting in bad output like https://gist.github.com/gmarek/9a11d5a305a52b193889684e56c103e4.

unblock #49112 
cc @gmarek

staging/src/k8s.io/code-generator/cmd/client-gen/generators/fake/generator_fake_for_group.go

@@ -40,13 +40,19 @@ type genFakeForGroup struct {
 	// types in this group
 	types   []*types.Type
 	imports namer.ImportTracker
+	// If the genGroup has been called. This generator should only execute once.
+	called bool
 }
 
 var _ generator.Generator = &genFakeForGroup{}
 
 // We only want to call GenerateType() once per group.
 func (g *genFakeForGroup) Filter(c *generator.Context, t *types.Type) bool {
-	return len(g.types) == 0 || t == g.types[0]
+	if !g.called {
+		g.called = true
+		return true
+	}
+	return false
 }
 
 func (g *genFakeForGroup) Namers(c *generator.Context) namer.NameSystems {
@@ -56,7 +62,10 @@ func (g *genFakeForGroup) Namers(c *generator.Context) namer.NameSystems {
 }
 
 func (g *genFakeForGroup) Imports(c *generator.Context) (imports []string) {
-	imports = append(g.imports.ImportLines(), strings.ToLower(fmt.Sprintf("%s \"%s\"", filepath.Base(g.realClientPackage), g.realClientPackage)))
+	imports = g.imports.ImportLines()
+	if len(g.types) != 0 {
+		imports = append(imports, strings.ToLower(fmt.Sprintf("%s \"%s\"", filepath.Base(g.realClientPackage), g.realClientPackage)))
+	}
 	return imports
 }
 

staging/src/k8s.io/code-generator/cmd/client-gen/generators/generator_for_group.go

@@ -41,13 +41,19 @@ type genGroup struct {
 	imports          namer.ImportTracker
 	inputPackage     string
 	clientsetPackage string
+	// If the genGroup has been called. This generator should only execute once.
+	called bool
 }
 
 var _ generator.Generator = &genGroup{}
 
 // We only want to call GenerateType() once per group.
 func (g *genGroup) Filter(c *generator.Context, t *types.Type) bool {
-	return len(g.types) == 0 || t == g.types[0]
+	if !g.called {
+		g.called = true
+		return true
+	}
+	return false
 }
 
 func (g *genGroup) Namers(c *generator.Context) namer.NameSystems {