appium-flutter-driver/lib/commands/assertions.ts

Appium Flutter driver

import {FlutterDriver} from '../driver';
import {byValueKey, byText, byTooltip} from 'appium-flutter-finder';
import type {SerializableFinder} from 'appium-flutter-finder';

export type FinderInput =
  | {key: string}
  | {text: string}
  | {label: string}
  | SerializableFinder
  | string
  | {getRawFinder: () => SerializableFinder}; // FlutterElement-like input

// Serialize a finder to base64
const serializeFinder = (finder: SerializableFinder): string =>
  Buffer.from(JSON.stringify(finder)).toString('base64');

// Type guards
const isRawFinder = (input: any): input is SerializableFinder =>
  input && typeof input === 'object' && typeof input.finderType === 'string';

const isFlutterElementLike = (input: any): input is {getRawFinder: () => SerializableFinder} =>
  input && typeof input === 'object' && typeof input.getRawFinder === 'function';

// Convert FinderInput to base64 string
function getFinderBase64(input: FinderInput): string {
  if (typeof input === 'string') {
    return input; // already base64
  }

  if (isFlutterElementLike(input)) {
    return serializeFinder(input.getRawFinder());
  }

  if (isRawFinder(input)) {
    return serializeFinder(input);
  }

  if ('key' in input) {
    return byValueKey(input.key);
  }

  if ('text' in input) {
    return byText(input.text);
  }

  if ('label' in input) {
    return byTooltip(input.label);
  }

  throw new Error(
    'Invalid finder input: must provide key, text, label, raw finder, or FlutterElement',
  );
}

// Generic helper to wrap assert commands
async function executeAssertion(
  driver: FlutterDriver,
  command: string,
  input: FinderInput,
  timeout = 5000,
  extraArgs: object = {},
): Promise<void> {
  const base64 = getFinderBase64(input);
  try {
    await driver.executeElementCommand(command, base64, {
      timeout,
      ...extraArgs,
    });
  } catch (err) {
    throw new Error(`Assertion failed on command "${command}" within ${timeout}ms\n${err}`);
  }
}

// Exported assertion commands
export const assertVisible = async (
  driver: FlutterDriver,
  input: FinderInput,
  timeout = 5000,
): Promise<void> => await executeAssertion(driver, 'waitFor', input, timeout, {visible: true});

export const assertNotVisible = async (
  driver: FlutterDriver,
  input: FinderInput,
  timeout = 5000,
): Promise<void> => await executeAssertion(driver, 'waitForAbsent', input, timeout);

export const assertTappable = async (
  driver: FlutterDriver,
  input: FinderInput,
  timeout = 5000,
): Promise<void> => await executeAssertion(driver, 'waitForTappable', input, timeout);