Support top-level enums in CRDs

kube-derive/src/custom_resource.rs

@@ -136,11 +136,11 @@ pub(crate) fn derive(input: proc_macro2::TokenStream) -> proc_macro2::TokenStrea
     };
     // Limit derive to structs
     match derive_input.data {
-        Data::Struct(_) => {}
+        Data::Struct(_) | Data::Enum(_) => {}
         _ => {
             return syn::Error::new_spanned(
                 &derive_input.ident,
-                r#"Enums or Unions can not #[derive(CustomResource)]"#,
+                r#"Unions can not #[derive(CustomResource)]"#,
             )
             .to_compile_error()
         }

kube-derive/tests/crd_enum_test.rs

@@ -0,0 +1,155 @@
+use kube_derive::CustomResource;
+use schemars::JsonSchema;
+use serde::{Deserialize, Serialize};
+
+#[derive(CustomResource, Serialize, Deserialize, Debug, Clone, JsonSchema)]
+#[kube(group = "clux.dev", version = "v1", kind = "FooEnum")]
+#[kube(apiextensions = "v1")]
+#[serde(rename_all = "camelCase")]
+enum FooEnumSpec {
+    /// First variant with an int
+    VariantOne { int: i32 },
+    /// Second variant with an String
+    VariantTwo { str: String },
+    /// Third variant which doesn't has an attribute
+    VariantThree {},
+}
+
+#[test]
+fn test_crd_name() {
+    use kube::core::CustomResourceExt;
+    assert_eq!("fooenums.clux.dev", FooEnum::crd_name());
+}
+
+#[test]
+fn test_serialized_matches_expected() {
+    assert_eq!(
+        serde_json::to_value(FooEnum::new("bar", FooEnumSpec::VariantOne { int: 42 })).unwrap(),
+        serde_json::json!({
+            "apiVersion": "clux.dev/v1",
+            "kind": "FooEnum",
+            "metadata": {
+                "name": "bar",
+            },
+            "spec": {
+                "variantOne": {
+                    "int": 42
+                }
+            }
+        })
+    );
+    assert_eq!(
+        serde_json::to_value(FooEnum::new("bar", FooEnumSpec::VariantThree {})).unwrap(),
+        serde_json::json!({
+            "apiVersion": "clux.dev/v1",
+            "kind": "FooEnum",
+            "metadata": {
+                "name": "bar",
+            },
+            "spec": {
+                "variantThree": {}
+            }
+        })
+    );
+}
+
+#[test]
+fn test_crd_schema_matches_expected() {
+    use kube::core::CustomResourceExt;
+
+    assert_eq!(
+        FooEnum::crd(),
+        serde_json::from_value(serde_json::json!({
+          "apiVersion": "apiextensions.k8s.io/v1",
+          "kind": "CustomResourceDefinition",
+          "metadata": {
+            "name": "fooenums.clux.dev"
+          },
+          "spec": {
+            "group": "clux.dev",
+            "names": {
+              "categories": [],
+              "kind": "FooEnum",
+              "plural": "fooenums",
+              "shortNames": [],
+              "singular": "fooenum"
+            },
+            "scope": "Cluster",
+            "versions": [
+              {
+                "additionalPrinterColumns": [],
+                "name": "v1",
+                "schema": {
+                  "openAPIV3Schema": {
+                    "description": "Auto-generated derived type for FooEnumSpec via `CustomResource`",
+                    "properties": {
+                      "spec": {
+                        "oneOf": [
+                          {
+                            "required": [
+                              "variantOne"
+                            ]
+                          },
+                          {
+                            "required": [
+                              "variantTwo"
+                            ]
+                          },
+                          {
+                            "required": [
+                              "variantThree"
+                            ]
+                          }
+                        ],
+                        "properties": {
+                          "variantOne": {
+                            "description": "First variant with an int",
+                            "properties": {
+                              "int": {
+                                "format": "int32",
+                                "type": "integer"
+                              }
+                            },
+                            "required": [
+                              "int"
+                            ],
+                            "type": "object"
+                          },
+                          "variantThree": {
+                            "description": "Third variant which doesn't has an attribute",
+                            "type": "object"
+                          },
+                          "variantTwo": {
+                            "description": "Second variant with an String",
+                            "properties": {
+                              "str": {
+                                "type": "string"
+                              }
+                            },
+                            "required": [
+                              "str"
+                            ],
+                            "type": "object"
+                          }
+                        },
+                        "type": "object"
+                      }
+                    },
+                    "required": [
+                      "spec"
+                    ],
+                    "title": "FooEnum",
+                    "type": "object"
+                  }
+                },
+                "served": true,
+                "storage": true,
+                "subresources": {}
+              }
+            ]
+          }
+        }
+        ))
+        .unwrap()
+    );
+}

kube-derive/tests/ui/enum_fails.rs → kube-derive/tests/ui/union_fails.rs

@@ -2,9 +2,9 @@ use kube_derive::CustomResource;
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
 
-#[derive(CustomResource, Serialize, Deserialize, Debug, Clone, JsonSchema)]
-enum FooSpec {
-    Foo,
+#[derive(CustomResource, Serialize, Deserialize, JsonSchema)]
+union FooSpec {
+    int: u32,
 }
 
 fn main() {}

kube-derive/tests/ui/union_fails.stderr

@@ -0,0 +1,13 @@
+error: Unions can not #[derive(CustomResource)]
+ --> tests/ui/union_fails.rs:6:7
+  |
+6 | union FooSpec {
+  |       ^^^^^^^
+
+error: Serde does not support derive for unions
+ --> tests/ui/union_fails.rs:6:1
+  |
+6 | / union FooSpec {
+7 | |     int: u32,
+8 | | }
+  | |_^