Introduce higher order function to log errors in decorated functions

Co-authored-by: Janne Savolainen <janne.savolainen@live.fi>

Signed-off-by: Iku-turso <mikko.aspiala@gmail.com>

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

@@ -0,0 +1,39 @@
+/**
+ * Copyright (c) OpenLens Authors. All rights reserved.
+ * Licensed under MIT License. See LICENSE in root directory for more information.
+ */
+import { getInjectable } from "@ogre-tools/injectable";
+import loggerInjectable from "../../logger.injectable";
+
+const withErrorLoggingInjectable = getInjectable({
+  id: "with-error-logging",
+
+  instantiate: (di) => {
+    const logger = di.inject(loggerInjectable);
+
+    return (getErrorMessage: (error: Error) => string) =>
+      <T extends (...args: any[]) => any>(toBeDecorated: T) =>
+        (...args: Parameters<T>): ReturnType<T> => {
+          try {
+            const returnValue = toBeDecorated(...args);
+
+            if (isPromise(returnValue)) {
+              returnValue.catch((e: Error) => {
+                logger.error(getErrorMessage(e as Error), e);
+              });
+            }
+
+            return returnValue;
+          } catch (e) {
+            logger.error(getErrorMessage(e as Error), e);
+            throw e;
+          }
+        };
+  },
+});
+
+export default withErrorLoggingInjectable;
+
+function isPromise(reference: any): reference is Promise<any> {
+  return !!reference?.then;
+}

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

@@ -0,0 +1,215 @@
+/**
+ * Copyright (c) OpenLens Authors. All rights reserved.
+ * Licensed under MIT License. See LICENSE in root directory for more information.
+ */
+
+import { getDiForUnitTesting } from "../../../main/getDiForUnitTesting";
+import loggerInjectable from "../../logger.injectable";
+import type { Logger } from "../../logger";
+import withErrorLoggingInjectable from "./with-error-logging.injectable";
+import { pipeline } from "@ogre-tools/fp";
+import type { AsyncFnMock } from "@async-fn/jest";
+import asyncFn from "@async-fn/jest";
+import { getPromiseStatus } from "../../test-utils/get-promise-status";
+
+describe("with-error-logging", () => {
+  describe("given decorated sync function", () => {
+    let loggerStub: Logger;
+    let toBeDecorated: jest.Mock<number | undefined, [string, string]>;
+    let decorated: (a: string, b: string) => number | undefined;
+
+    beforeEach(() => {
+      const di = getDiForUnitTesting();
+
+      loggerStub = {
+        error: jest.fn(),
+      } as unknown as Logger;
+
+      di.override(loggerInjectable, () => loggerStub);
+
+      const withErrorLoggingFor = di.inject(withErrorLoggingInjectable);
+
+      toBeDecorated = jest.fn();
+
+      decorated = pipeline(
+        toBeDecorated,
+        withErrorLoggingFor((error: Error) => `some-error-message-for-${error.message}`),
+      );
+    });
+
+    describe("when function does not throw and returns value", () => {
+      let returnValue: number | undefined;
+
+      beforeEach(() => {
+        // eslint-disable-next-line unused-imports/no-unused-vars-ts
+        toBeDecorated.mockImplementation((_, __) => 42);
+
+        returnValue = decorated("some-parameter", "some-other-parameter");
+      });
+
+      it("passes arguments to decorated function", () => {
+        expect(toBeDecorated).toHaveBeenCalledWith("some-parameter", "some-other-parameter");
+      });
+
+      it("does not log error", () => {
+        expect(loggerStub.error).not.toHaveBeenCalled();
+      });
+
+      it("returns the value", () => {
+        expect(returnValue).toBe(42);
+      });
+    });
+
+    describe("when function does not throw and returns no value", () => {
+      let returnValue: number | undefined;
+
+      beforeEach(() => {
+        // eslint-disable-next-line unused-imports/no-unused-vars-ts
+        toBeDecorated.mockImplementation((_, __) => undefined);
+
+        returnValue = decorated("some-parameter", "some-other-parameter");
+      });
+
+      it("passes arguments to decorated function", () => {
+        expect(toBeDecorated).toHaveBeenCalledWith("some-parameter", "some-other-parameter");
+      });
+
+      it("does not log error", () => {
+        expect(loggerStub.error).not.toHaveBeenCalled();
+      });
+
+      it("returns nothing", () => {
+        expect(returnValue).toBeUndefined();
+      });
+    });
+
+    describe("when function throws", () => {
+      let error: Error;
+
+      beforeEach(() => {
+        // eslint-disable-next-line unused-imports/no-unused-vars-ts
+        toBeDecorated.mockImplementation((_, __) => {
+          throw new Error("some-error");
+        });
+
+        try {
+          decorated("some-parameter", "some-other-parameter");
+        } catch (e: any) {
+          error = e;
+        }
+      });
+
+      it("passes arguments to decorated function", () => {
+        expect(toBeDecorated).toHaveBeenCalledWith("some-parameter", "some-other-parameter");
+      });
+
+      it("logs the error", () => {
+        expect(loggerStub.error).toHaveBeenCalledWith("some-error-message-for-some-error", error);
+      });
+
+      it("throws", () => {
+        expect(error.message).toBe("some-error");
+      });
+    });
+  });
+
+  describe("given decorated async function", () => {
+    let loggerStub: Logger;
+    let decorated: (a: string, b: string) => Promise<number | undefined>;
+    let toBeDecorated: AsyncFnMock<typeof decorated>;
+
+    beforeEach(() => {
+      const di = getDiForUnitTesting();
+
+      loggerStub = {
+        error: jest.fn(),
+      } as unknown as Logger;
+
+      di.override(loggerInjectable, () => loggerStub);
+
+      const withErrorLoggingFor = di.inject(withErrorLoggingInjectable);
+
+      toBeDecorated = asyncFn();
+
+      decorated = pipeline(
+        toBeDecorated,
+        withErrorLoggingFor((error: Error) => `some-error-message-for-${error.message}`),
+      );
+    });
+
+    describe("when called", () => {
+      let returnValuePromise: Promise<number | undefined>;
+
+      beforeEach(() => {
+        returnValuePromise = decorated("some-parameter", "some-other-parameter");
+      });
+
+      it("passes arguments to decorated function", () => {
+        expect(toBeDecorated).toHaveBeenCalledWith("some-parameter", "some-other-parameter");
+      });
+
+      it("does not log error yet", () => {
+        expect(loggerStub.error).not.toHaveBeenCalled();
+      });
+
+      it("does not resolve yet", async () => {
+        const promiseStatus = await getPromiseStatus(returnValuePromise);
+
+        expect(promiseStatus.fulfilled).toBe(false);
+      });
+
+      describe("when call rejects", () => {
+        let error: Error;
+
+        beforeEach(async () => {
+          try {
+            await toBeDecorated.reject(new Error("some-error"));
+            await returnValuePromise;
+          } catch (e) {
+            error = e as Error;
+          }
+        });
+
+        it("logs the error", () => {
+          expect(loggerStub.error).toHaveBeenCalledWith("some-error-message-for-some-error", error);
+        });
+
+        it("rejects", () => {
+          return expect(() => returnValuePromise).rejects.toThrow("some-error");
+        });
+      });
+
+      describe("when call resolves with value", () => {
+        beforeEach(async () => {
+          await toBeDecorated.resolve(42);
+        });
+
+        it("does not log error", () => {
+          expect(loggerStub.error).not.toHaveBeenCalled();
+        });
+
+        it("resolves with the value", async () => {
+          const returnValue = await returnValuePromise;
+
+          expect(returnValue).toBe(42);
+        });
+      });
+
+      describe("when call resolves without value", () => {
+        beforeEach(async () => {
+          await toBeDecorated.resolve(undefined);
+        });
+
+        it("does not log error", () => {
+          expect(loggerStub.error).not.toHaveBeenCalled();
+        });
+
+        it("resolves with the value", async () => {
+          const returnValue = await returnValuePromise;
+
+          expect(returnValue).toBeUndefined();
+        });
+      });
+    });
+  });
+});