Make code for asserting a promise more strict

Co-authored-by: Mikko Aspiala <mikko.aspiala@gmail.com>

Signed-off-by: Janne Savolainen <janne.savolainen@live.fi>

src/common/utils/is-promise/is-promise.test.ts

@@ -0,0 +1,31 @@
+/**
+ * Copyright (c) OpenLens Authors. All rights reserved.
+ * Licensed under MIT License. See LICENSE in root directory for more information.
+ */
+import { isPromise } from "./is-promise";
+
+describe("isPromise", () => {
+  it("given promise, returns true", () => {
+    const actual = isPromise(new Promise(() => {}));
+
+    expect(actual).toBe(true);
+  });
+
+  it("given non-promise, returns false", () => {
+    const actual = isPromise({});
+
+    expect(actual).toBe(false);
+  });
+
+  it("given thenable, returns false", () => {
+    const actual = isPromise({ then: () => {} });
+
+    expect(actual).toBe(false);
+  });
+
+  it("given nothing, returns false", () => {
+    const actual = isPromise(undefined);
+
+    expect(actual).toBe(false);
+  });
+});

src/common/utils/is-promise/is-promise.ts

@@ -0,0 +1,7 @@
+/**
+ * Copyright (c) OpenLens Authors. All rights reserved.
+ * Licensed under MIT License. See LICENSE in root directory for more information.
+ */
+export function isPromise(reference: any): reference is Promise<any> {
+  return reference?.constructor === Promise;
+}

src/common/utils/with-error-logging/with-error-logging.injectable.ts

@@ -4,6 +4,7 @@
  */
 import { getInjectable } from "@ogre-tools/injectable";
 import loggerInjectable from "../../logger.injectable";
+import { isPromise } from "../is-promise/is-promise";
 
 export type WithErrorLoggingFor = (
   getErrorMessage: (error: unknown) => string
@@ -44,7 +45,3 @@ const withErrorLoggingInjectable = getInjectable({
 });
 
 export default withErrorLoggingInjectable;
-
-function isPromise(reference: any): reference is Promise<any> {
-  return !!reference?.then;
-}