Improve resource kind typing (#1251)

With these changes, `Kube.resourcePlural("Dummy")` is a type error, so
the non-existing resource kind test should not be needed anymore.

dashboard/src/shared/Kube.test.ts

@@ -100,23 +100,4 @@ describe("App", () => {
       socket.close();
     });
   });
-
-  describe("resourcePlural", () => {
-    const tests = [
-      { kind: "Service", expected: "services" },
-      { kind: "Ingress", expected: "ingresses" },
-      { kind: "Deployment", expected: "deployments" },
-    ];
-    tests.forEach(t => {
-      it(`returns the correct plural for ${t.kind}`, () => {
-        expect(Kube.resourcePlural(t.kind)).toBe(t.expected);
-      });
-    });
-
-    it("throws an error if the resource kind isn't registered", () => {
-      expect(() => Kube.resourcePlural("ThisKindWillNeverExist")).toThrow(
-        "Don't know plural for ThisKindWillNeverExist, register it in Kube",
-      );
-    });
-  });
 });

dashboard/src/shared/Kube.ts

@@ -1,5 +1,6 @@
 import { Auth } from "./Auth";
 import { axiosWithAuth } from "./AxiosInstance";
+import { ResourceKind, ResourceKindsWithPlurals } from "./ResourceKinds";
 import { IResource } from "./types";
 
 export const APIBase = "api/kube";
@@ -10,19 +11,6 @@ if (location.protocol === "https:") {
   WebSocketAPIBase = `ws://${window.location.host}${window.location.pathname}`;
 }
 
-// We explicitly define the plurals here, just in case a generic pluralizer
-// isn't sufficient. Note that CRDs can explicitly define pluralized forms,
-// which might not match with the Kind. If this becomes difficult to
-// maintain we can add a generic pluralizer and a way to override.
-const ResourceKindToPlural = {
-  Secret: "secrets",
-  Service: "services",
-  Ingress: "ingresses",
-  Deployment: "deployments",
-  StatefulSet: "statefulsets",
-  DaemonSet: "daemonsets",
-};
-
 // Kube is a lower-level class for interacting with the Kubernetes API. Use
 // ResourceRef to interact with a single API resource rather than using Kube
 // directly.
@@ -97,11 +85,7 @@ export class Kube {
   }
 
   // Gets the plural form of the resource Kind for use in the resource path
-  public static resourcePlural(kind: string) {
-    const plural = ResourceKindToPlural[kind];
-    if (!plural) {
-      throw new Error(`Don't know plural for ${kind}, register it in Kube`);
-    }
-    return plural;
+  public static resourcePlural(kind: ResourceKind) {
+    return ResourceKindsWithPlurals[kind];
   }
 }

dashboard/src/shared/ResourceKinds.ts

@@ -0,0 +1,16 @@
+// We explicitly define the plurals here, just in case a generic pluralizer
+// isn't sufficient. Note that CRDs can explicitly define pluralized forms,
+// which might not match with the Kind. If this becomes difficult to
+// maintain we can add a generic pluralizer and a way to override.
+export const ResourceKindsWithPlurals = {
+  ClusterRole: "clusterroles",
+  ConfigMap: "configmaps",
+  DaemonSet: "daemonsets",
+  Deployment: "deployments",
+  Ingress: "ingresses",
+  Secret: "secrets",
+  Service: "services",
+  StatefulSet: "statefulsets",
+} as const;
+
+export type ResourceKind = keyof typeof ResourceKindsWithPlurals;

dashboard/src/shared/ResourceRef.ts

@@ -1,11 +1,12 @@
 import { Kube } from "./Kube";
+import { ResourceKind } from "./ResourceKinds";
 import { IResource } from "./types";
 
 // ResourceRef defines a reference to a namespaced Kubernetes API Object and
 // provides helpers to retrieve the resource URL
 class ResourceRef {
   public apiVersion: string;
-  public kind: string;
+  public kind: ResourceKind;
   public name: string;
   public namespace: string;
 

dashboard/src/shared/types.ts

@@ -4,6 +4,7 @@ import { IConfigState } from "../reducers/config";
 import { INamespaceState } from "../reducers/namespace";
 import { IAppRepositoryState } from "../reducers/repos";
 import { hapi } from "./hapi/release";
+import { ResourceKind } from "./ResourceKinds";
 
 // Allow defining multiple error classes
 // tslint:disable:max-classes-per-file
@@ -141,7 +142,7 @@ export interface IIngressSpec {
 
 export interface IResource {
   apiVersion: string;
-  kind: string;
+  kind: ResourceKind;
   type: string;
   spec: any;
   status: any;