From 78106a265a358ee6af1b7f154763ffe63f1226ed Mon Sep 17 00:00:00 2001
From: Emily M Klassen <forivall@gmail.com>
Date: Thu, 9 May 2024 18:17:20 -0700
Subject: [PATCH 1/2] test: add dtslint check for interop

---
 spec-dtslint/helpers.ts    | 32 ++++++++++++++++++++++++++++++++
 spec-dtslint/types-spec.ts |  7 ++++++-
 2 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/spec-dtslint/helpers.ts b/spec-dtslint/helpers.ts
index 107e0e20b4..effc449c66 100644
--- a/spec-dtslint/helpers.ts
+++ b/spec-dtslint/helpers.ts
@@ -32,3 +32,35 @@ export const g$ = of(new G());
 export const h$ = of(new H());
 export const i$ = of(new I());
 export const j$ = of(new J());
+
+interface Subscription {
+  closed: boolean;
+  unsubscribe(): void;
+}
+interface SubscriptionObserver<T> {
+  closed: boolean;
+  next(value: T): void;
+  error(errorValue: any): void;
+  complete(): void;
+}
+type Subscriber<T> = (observer: SubscriptionObserver<T>) => void | (() => void) | Subscription;
+
+interface Observer<T> {
+  start?(subscription: Subscription): any;
+  next?(value: T): void;
+  error?(errorValue: any): void;
+  complete?(): void;
+}
+
+export declare class CompatObservable<T> {
+  constructor(subscriber: Subscriber<T>);
+
+  subscribe(observer: Observer<T>): Subscription;
+  subscribe(
+      onNext: (value: T) => void,
+      onError?: (error: any) => void,
+      onComplete?: () => void,
+  ): Subscription;
+
+  [Symbol.observable](): CompatObservable<T>;
+}
diff --git a/spec-dtslint/types-spec.ts b/spec-dtslint/types-spec.ts
index ef7aab679c..781e4cc29b 100644
--- a/spec-dtslint/types-spec.ts
+++ b/spec-dtslint/types-spec.ts
@@ -7,7 +7,7 @@ import {
   Head,
   Tail
 } from 'rxjs';
-import { A, B, C } from './helpers';
+import { A, B, C, CompatObservable } from './helpers';
 
 describe('ObservedValueOf', () => {
   it('should infer from an observable', () => {
@@ -24,6 +24,11 @@ describe('ObservedValueOf', () => {
     let explicit: ObservedValueOf<Promise<A>>;
     let inferred = explicit!; // $ExpectType A
   });
+
+  it('should infer from an compatible observable', () => {
+    let explicit: ObservedValueOf<CompatObservable<A>>;
+    const inferred = explicit!; // $ExpectType A
+  });
 });
 
 describe('ObservedUnionFromArray', () => {

From 293ff154bf67f54c002dda9372e46d2eaf3ee8c1 Mon Sep 17 00:00:00 2001
From: Emily M Klassen <forivall@gmail.com>
Date: Thu, 9 May 2024 18:19:01 -0700
Subject: [PATCH 2/2] fix(types): improve interop with zen observable

---
 src/internal/types.ts | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/internal/types.ts b/src/internal/types.ts
index b72eab3a11..52964cc910 100644
--- a/src/internal/types.ts
+++ b/src/internal/types.ts
@@ -97,6 +97,11 @@ export interface Subscribable<T> {
   subscribe(observer: Partial<Observer<T>>): Unsubscribable;
 }
 
+export interface InteropSubscribable<T> {
+  subscribe(observer: Partial<Observer<T>>): Unsubscribable;
+  subscribe(onNext?: (value: T) => void, onError?: (error: any) => void, onComplete?: () => void): Subscription;
+}
+
 /**
  * Valid types that can be converted to observables.
  */
@@ -118,7 +123,7 @@ export type ObservableLike<T> = InteropObservable<T>;
  * An object that implements the `Symbol.observable` interface.
  */
 export interface InteropObservable<T> {
-  [Symbol.observable]: () => Subscribable<T>;
+  [Symbol.observable]: () => Subscribable<T> | InteropSubscribable<T>;
 }
 
 /* NOTIFICATIONS */