chore: more tests (#1862)

Author: mdjastrzebski

AGENTS.md

@@ -41,6 +41,7 @@ The project uses `yarn` for dependency management and script execution.
   - **Location:** Tests are located within `src`, typically co-located in `__tests__` directories.
   - **Setup:** `jest-setup.ts` configures the test environment. `src/index.ts` automatically configures cleanup after each test unless skipped.
   - **Coverage:** Collected from `src`, excluding tests.
+  - **Organization:** Use `describe` to group test by theme. Avoid putting all tests in the same `describe` block. Avoid `describe` nesting. Avoid `describe` with only single test, make that test top-level. Prefere `test` over `it`.
 
 - **Commits & Releases:**
   - **Commits:** Follow the **Conventional Commits** specification (e.g., `fix:`, `feat:`, `chore:`). This is enforced and used for changelog generation.

src/event-handler.ts

@@ -30,7 +30,7 @@ export function getEventHandlerFromProps(
   return undefined;
 }
 
-export function getEventHandlerName(eventName: string) {
+function getEventHandlerName(eventName: string) {
   return `on${capitalizeFirstLetter(eventName)}`;
 }
 

src/fire-event.ts

@@ -17,7 +17,7 @@ import { isEditableTextInput } from './helpers/text-input';
 import { nativeState } from './native-state';
 import type { Point, StringWithAutocomplete } from './types';
 
-export function isTouchResponder(element: HostElement) {
+function isTouchResponder(element: HostElement) {
   return Boolean(element.props.onStartShouldSetResponder) || isHostTextInput(element);
 }
 
@@ -44,7 +44,7 @@ const textInputEventsIgnoringEditableProp = new Set([
   'onScroll',
 ]);
 
-export function isEventEnabled(
+function isEventEnabled(
   element: HostElement,
   eventName: string,
   nearestTouchResponder?: HostElement,

src/helpers/__tests__/errors.test.ts

@@ -0,0 +1,74 @@
+import { copyStackTrace, ErrorWithStack } from '../errors';
+
+describe('ErrorWithStack', () => {
+  test('should create an error with message', () => {
+    const error = new ErrorWithStack('Test error', ErrorWithStack);
+    expect(error.message).toBe('Test error');
+    expect(error).toBeInstanceOf(Error);
+
+    const originalCaptureStackTrace = Error.captureStackTrace;
+    // @ts-expect-error - intentionally removing captureStackTrace
+    delete Error.captureStackTrace;
+
+    const errorWithoutCapture = new ErrorWithStack('Test error', ErrorWithStack);
+    expect(errorWithoutCapture.message).toBe('Test error');
+    expect(errorWithoutCapture).toBeInstanceOf(Error);
+
+    Error.captureStackTrace = originalCaptureStackTrace;
+  });
+
+  test('should capture stack trace if Error.captureStackTrace is available', () => {
+    const originalCaptureStackTrace = Error.captureStackTrace;
+    const captureStackTraceSpy = jest.fn();
+    Error.captureStackTrace = captureStackTraceSpy;
+
+    const error = new ErrorWithStack('Test error', ErrorWithStack);
+    expect(captureStackTraceSpy).toHaveBeenCalledWith(error, ErrorWithStack);
+
+    Error.captureStackTrace = originalCaptureStackTrace;
+  });
+});
+
+describe('copyStackTrace', () => {
+  test('should copy stack trace from source to target when both are Error instances', () => {
+    const target = new Error('Target error');
+    const source = new Error('Source error');
+    source.stack = 'Error: Source error\n    at test.js:1:1';
+
+    copyStackTrace(target, source);
+    expect(target.stack).toBe('Error: Target error\n    at test.js:1:1');
+
+    const target2 = new Error('Target error');
+    const source2 = new Error('Source error');
+    source2.stack =
+      'Error: Source error\n    at test.js:1:1\nError: Source error\n    at test.js:2:2';
+
+    copyStackTrace(target2, source2);
+    // Should replace only the first occurrence
+    expect(target2.stack).toBe(
+      'Error: Target error\n    at test.js:1:1\nError: Source error\n    at test.js:2:2',
+    );
+  });
+
+  test('should not modify target when conditions are not met', () => {
+    const targetNotError = { message: 'Not an error' };
+    const source = new Error('Source error');
+    source.stack = 'Error: Source error\n    at test.js:1:1';
+
+    copyStackTrace(targetNotError, source);
+    expect(targetNotError).toEqual({ message: 'Not an error' });
+
+    const target = new Error('Target error');
+    const originalStack = target.stack;
+    const sourceNotError = { message: 'Not an error' };
+
+    copyStackTrace(target, sourceNotError as Error);
+    expect(target.stack).toBe(originalStack);
+
+    const sourceNoStack = new Error('Source error');
+    delete sourceNoStack.stack;
+
+    copyStackTrace(target, sourceNoStack);
+    expect(target.stack).toBe(originalStack);
+  });
+});

src/helpers/errors.ts

@@ -1,5 +1,3 @@
-import prettyFormat from 'pretty-format';
-
 export class ErrorWithStack extends Error {
   // eslint-disable-next-line @typescript-eslint/no-unsafe-function-type
   constructor(message: string | undefined, callsite: Function) {
@@ -10,44 +8,6 @@ export class ErrorWithStack extends Error {
   }
 }
 
-export const prepareErrorMessage = (
-  // TS states that error caught in a catch close are of type `unknown`
-  // most real cases will be `Error`, but better safe than sorry
-  error: unknown,
-  name?: string,
-  value?: unknown,
-): string => {
-  let errorMessage: string;
-  if (error instanceof Error) {
-    // Strip info about custom predicate
-    errorMessage = error.message.replace(/ matching custom predicate[^]*/gm, '');
-  } else if (error && typeof error === 'object') {
-    errorMessage = error.toString();
-  } else {
-    errorMessage = 'Caught unknown error';
-  }
-
-  if (name && value) {
-    errorMessage += ` with ${name} ${prettyFormat(value, { min: true })}`;
-  }
-  return errorMessage;
-};
-
-// eslint-disable-next-line @typescript-eslint/no-unsafe-function-type
-export const createQueryByError = (error: unknown, callsite: Function): null => {
-  if (error instanceof Error) {
-    if (error.message.includes('No instances found')) {
-      return null;
-    }
-    throw new ErrorWithStack(error.message, callsite);
-  }
-
-  throw new ErrorWithStack(
-    `Query: caught unknown error type: ${typeof error}, value: ${error}`,
-    callsite,
-  );
-};
-
 export function copyStackTrace(target: unknown, stackTraceSource: Error) {
   if (target instanceof Error && stackTraceSource.stack) {
     target.stack = stackTraceSource.stack.replace(stackTraceSource.message, target.message);

src/user-event/event-builder/__tests__/base.test.ts

@@ -0,0 +1,35 @@
+import { baseSyntheticEvent } from '../base';
+
+test('returns object with all required properties and default values', () => {
+  const event = baseSyntheticEvent();
+
+  expect(event.currentTarget).toEqual({});
+  expect(event.target).toEqual({});
+  expect(event.timeStamp).toBe(0);
+  expect(event.isDefaultPrevented?.()).toBe(false);
+  expect(event.isPropagationStopped?.()).toBe(false);
+  expect(event.isPersistent?.()).toBe(false);
+  expect(typeof event.stopPropagation).toBe('function');
+  expect(typeof event.preventDefault).toBe('function');
+  expect(typeof event.persist).toBe('function');
+});
+
+test('returns a new object instance on each call', () => {
+  const event1 = baseSyntheticEvent();
+  const event2 = baseSyntheticEvent();
+
+  expect(event1).not.toBe(event2);
+  expect(event1.currentTarget).not.toBe(event2.currentTarget);
+  expect(event1.target).not.toBe(event2.target);
+});
+
+test('can be spread into other objects', () => {
+  const extendedEvent = {
+    ...baseSyntheticEvent(),
+    nativeEvent: { test: 'value' },
+  };
+
+  expect(extendedEvent).toHaveProperty('currentTarget');
+  expect(extendedEvent).toHaveProperty('preventDefault');
+  expect(extendedEvent.nativeEvent).toEqual({ test: 'value' });
+});

src/user-event/event-builder/base.ts

@@ -1,7 +1,12 @@
 import type { BaseSyntheticEvent } from 'react';
 
 /** Builds base syntentic event stub, with prop values as inspected in RN runtime. */
-export function baseSyntheticEvent(): Partial<BaseSyntheticEvent<object, unknown, unknown>> {
+type BaseEvent = Partial<BaseSyntheticEvent<object, unknown, unknown>> & {
+  // `isPersistent` is not a standard prop, but it's used in RN runtime. See: https://react.dev/reference/react-dom/components/common#react-event-object-methods
+  isPersistent: () => boolean;
+};
+
+export function baseSyntheticEvent(): BaseEvent {
   return {
     currentTarget: {},
     target: {},
@@ -10,7 +15,6 @@ export function baseSyntheticEvent(): Partial<BaseSyntheticEvent<object, unknown
     stopPropagation: () => {},
     isPropagationStopped: () => false,
     persist: () => {},
-    // @ts-expect-error: `isPersistent` is not a standard prop, but it's used in RN runtime. See: https://react.dev/reference/react-dom/components/common#react-event-object-methods
     isPersistent: () => false,
     timeStamp: 0,
   };