Typescript user-defined type guard functions for patterns

CHANGELOG.md

@@ -9,7 +9,7 @@ Changelog for the docker image are [here](/docker_CHANGELOG.md).
 
 ## [Unreleased]
 
-### Added 
+### Added
 
 - Validate that we can't have multiple patterns with the same name (#1733)
 

docker_CHANGELOG.md

@@ -9,6 +9,10 @@ Changelog for the npm version are [here](/CHANGELOG.md).
 
 ## [Unreleased]
 
+### Added
+
+- Typescript user-defined type guard functions for patterns (#1735)
+
 ## [0.1.16] - 2023-12-09
 
 ### Fixed

examples/simple/src/ent/tests/mixin.test.ts

@@ -0,0 +1,74 @@
+import { User, Contact, Event, isFeedback } from "../../ent";
+import { randomEmail, randomPhoneNumber } from "../../util/random";
+import CreateUserAction from "../user/actions/create_user_action";
+import CreateContactAction, {
+  ContactCreateInput,
+} from "../contact/actions/create_contact_action";
+import { LoggedOutExampleViewer, ExampleViewer } from "../../viewer/viewer";
+import { ContactLabel } from "../generated/types";
+import CreateEventAction, {
+  EventCreateInput,
+} from "../event/actions/create_event_action";
+
+const loggedOutViewer = new LoggedOutExampleViewer();
+
+async function createUser(): Promise<User> {
+  return CreateUserAction.create(loggedOutViewer, {
+    firstName: "Jon",
+    lastName: "Snow",
+    emailAddress: randomEmail(),
+    phoneNumber: randomPhoneNumber(),
+    password: "pa$$w0rd",
+  }).saveX();
+}
+
+async function createContact(
+  user: User,
+  firstName: string,
+  lastName: string,
+  partial?: Partial<ContactCreateInput>,
+): Promise<Contact> {
+  return CreateContactAction.create(new ExampleViewer(user.id), {
+    emails: [
+      {
+        emailAddress: randomEmail(),
+        label: ContactLabel.Default,
+      },
+    ],
+    firstName: firstName,
+    lastName: lastName,
+    userID: user.id,
+    ...partial,
+  }).saveX();
+}
+
+async function createEvent(
+  startTime: Date,
+  partial?: Partial<EventCreateInput>,
+): Promise<Event> {
+  let user = await createUser();
+
+  return CreateEventAction.create(loggedOutViewer, {
+    name: "fun event",
+    creatorID: user.id,
+    startTime: startTime,
+    location: "location",
+    ...partial,
+  }).saveX();
+}
+
+test("feedback user", async () => {
+  const user = await createUser();
+  expect(isFeedback(user)).toBe(true);
+});
+
+test("feedback contact", async () => {
+  const user = await createUser();
+  const contact = await createContact(user, "Jon", "Snow");
+  expect(isFeedback(contact)).toBe(true);
+});
+
+test("feedback event", async () => {
+  const event = await createEvent(new Date());
+  expect(isFeedback(event)).toBe(false);
+});

internal/tscode/mixin.tmpl

@@ -10,6 +10,10 @@ type Constructor<T = {}> = new (...args: any[]) => T;
   {{ reserveImportPath . false -}}
 {{ end}}
 
+export function {{$p.GetPatternMethod}}(ent: unknown): ent is {{$p.GetMixinInterfaceName}} {
+  const o = ent as {{$p.GetMixinInterfaceName}};
+  return o.{{$p.GetPatternMethod}} && o.{{$p.GetPatternMethod}}() ?? false;
+}
 
 export interface {{$p.GetMixinInterfaceName}} {
   {{$p.GetPatternMethod}}(): boolean;