Namespace schema does not correctly show permitted collectionMethods

pkg/schema/factory.go

@@ -32,6 +32,23 @@ func newSchemas() (*types.APISchemas, error) {
 	return apiSchemas, nil
 }
 
+// Returns the new duplicate free slice.
+func uniq(s []string) []string {
+	length := len(s)
+	found := make(map[string]struct{})
+	result := make([]string, 0, length)
+
+	for i := 0; i < length; i++ {
+		v := s[i]
+		if _, ok := found[v]; !ok {
+			found[v] = struct{}{}
+			result = append(result, v)
+		}
+	}
+
+	return result
+}
+
 func (c *Collection) Schemas(user user.Info) (*types.APISchemas, error) {
 	access := c.as.AccessFor(user)
 	c.removeOldRecords(access, user)
@@ -128,7 +145,8 @@ func (c *Collection) schemasForSubject(access *accesscontrol.AccessSet) (*types.
 				verbAccess["get"] = accessList
 				verbAccess["watch"] = accessList
 				if len(accessList) == 0 {
-					// always allow list
+					// always allow list. note, this can lead to duplicates
+					// which will be removed later.
 					s.CollectionMethods = append(s.CollectionMethods, http.MethodGet)
 				}
 			}
@@ -162,6 +180,8 @@ func (c *Collection) schemasForSubject(access *accesscontrol.AccessSet) (*types.
 			continue
 		}
 
+		s.CollectionMethods = uniq(s.CollectionMethods)
+
 		if err := result.AddSchema(*s); err != nil {
 			return nil, err
 		}

pkg/schema/factory_test.go

@@ -58,6 +58,7 @@ func TestSchemas(t *testing.T) {
 		})
 	}
 }
+
 func TestSchemaCache(t *testing.T) {
 	// Schemas are a frequently used resource. It's important that the cache doesn't have a leak given size/frequency of resource
 	tests := []struct {
@@ -120,6 +121,43 @@ func TestSchemaCache(t *testing.T) {
 	}
 }
 
+func TestUniq(t *testing.T) {
+	tests := []struct {
+		name          string
+		param         []string
+		desiredResult []string
+	}{
+		{
+			name:          "remove duplicates [1/4]",
+			param:         []string{"GET", "POST", "PUT"},
+			desiredResult: []string{"GET", "POST", "PUT"},
+		},
+		{
+			name:          "remove duplicates [2/4]",
+			param:         []string{"GET", "GET", "POST"},
+			desiredResult: []string{"GET", "POST"},
+		},
+		{
+			name:          "remove duplicates [3/4]",
+			param:         []string{"DELETE"},
+			desiredResult: []string{"DELETE"},
+		},
+		{
+			name:          "remove duplicates [4/4]",
+			param:         []string{},
+			desiredResult: []string{},
+		},
+	}
+	for _, test := range tests {
+		test := test
+		t.Run(test.name, func(t *testing.T) {
+			t.Parallel()
+			result := uniq(test.param)
+			assert.Equal(t, result, test.desiredResult)
+		})
+	}
+}
+
 func runSchemaTest(t *testing.T, config schemaTestConfig, lookup *mockAccessSetLookup, collection *Collection, testUser user.Info) {
 	for _, verb := range config.permissionVerbs {
 		lookup.AddAccessForUser(testUser, verb, k8sSchema.GroupResource{Group: testGroup, Resource: "testCRD"}, "*", "*")