How to use jest - 10 common examples

public async shouldExist(selector: string, log?: string) {
    //const element = await this.app.client.element(selector);
    const exists = await this.app.client.waitForExist(selector, 2 * 1000);

    if (exists) {
      // console.log(log ? log : `Found element matching '${selector}'`);
    } else {
      console.log(log ? log : `Could not find element matching '${selector}'`);
      throw new Error(`Could not find element matching '${selector}'`);
    }
    expect(exists).toBe(true);
  }

);

    // Copy dist folder
    fs.copySync(
      path.resolve(rootDir, 'dist'),
      path.resolve(testCaseModuleFolder, 'dist')
    );
  });
}

createIntegrationMock();

const argv = process.argv.slice(2);
argv.push('--no-cache');
argv.push('--config', path.join(Paths.rootDir, 'jest.config.tests.js'));
jest.run(argv);

if (allFunctions.indexOf(functionName) >= 0) {
          setEnv(serverless, functionName);
          Object.assign(config, { testRegex: `${functionName}\\.test\\.[jt]s$` });
        } else {
          return reject(`Function "${functionName}" not found`);
        }
      } else {
        const functionsRegex = allFunctions.map(name => `${name}\\.test\\.[jt]s$`).join('|');
        Object.assign(config, { testRegex: functionsRegex });
      }
    }

    // eslint-disable-next-line dot-notation
    process.env['SERVERLESS_TEST_ROOT'] = serverless.config.servicePath;

    return runCLI(config, [serverless.config.servicePath])
      .then((output) => {
        if (output.results.success) {
          resolve(output);
        } else {
          reject(output.results);
        }
      })
      .catch(e => reject(e));
  });

public async shouldNotExist(selector: string, log?: string) {
    //const element = await this.app.client.element(selector);
    const exists = await this.app.client.isExisting(selector);

    // if (exists) {
    //   throw new Error(`Should not have found element matching '${selector}'`);
    // }
    expect(exists).toBe(false);
  }

(args, rawArgv) => {
      const rootDir = api.resolve('.');
      // 获取默认配置
      const defaultConfig = new DefaultConfigResolver(rootDir);

      const configuration = new JestConfigurationBuilder(
        defaultConfig,
        new CustomConfigResolver()
      ).buildConfiguration(process.cwd());
      rawArgv.push('--config', JSON.stringify(configuration));
      // 未查找到测试文件正常退出
      rawArgv.push('--passWithNoTests');
      run(rawArgv)
        .then((result) => {
          debug(result);
        })
        .catch((e) => {
          console.log(e);
        });
    }
  );

const flags = toFlags(opts, { allowCamelCase: true });

      const configDir = path.join(__dirname, 'configs', name);
      const configPath = path.join(configDir, 'config.js');

      // const createConfig = require(configDir);
      const { default: createConfig } = await import(configDir);

      const config = createConfig({ ...opts, ignores, input: inputs });
      const contents = `module.exports=${JSON.stringify(config)}`;

      fs.writeFileSync(configPath, contents);

      // eslint-disable-next-line global-require
      console.log('Jest', require('jest/package.json').version);

      console.log(`jest -c ${configPath} ${flags}`);

      return exec(`jest -c ${configPath} ${flags}`, { stdio: 'inherit' });
    });
}

const { getVersion: getJestVersion } = require('jest');
const chalk = require('chalk');
const configOverrides = require('../utils/configOverrides');

const majorJestVersion = parseInt(getJestVersion().split('.')[0], 10);

if (majorJestVersion < 23) {
  // eslint-disable-next-line no-console
  throw new Error(`Insufficient Jest version for jest-runner-eslint watch plugin
  
  Watch plugins are only available in Jest 23.0.0 and above.
  Upgrade your version of Jest in order to use it.
`);
}

class ESLintWatchFixPlugin {
  constructor({ stdout, config }) {
    this._stdout = stdout;
    this._key = config.key || 'F';
  }

const appDirectory = fs.realpathSync(process.cwd());

// Run Jest on the application files (./www/* & ./server/*)
const jest = require("jest");
let jestConfig = require("./config");
jestConfig.roots = [appDirectory];
delete jestConfig.collectCoverageFrom;
delete jestConfig.coverageDirectory;
delete jestConfig.reporters;
const jestCommand = [
  "--env=jsdom",
  "--watchAll",
  "--config",
  JSON.stringify(jestConfig)
];
jest.run(jestCommand);

function unitTest(projectDir) {
  const configPath = path.join(projectDir, 'jest.config.js');
  const jestConfig = fs.pathExistsSync(configPath)
    ? require(configPath)
    : require('./webpack/jest-config');
  const argv = {config: JSON.stringify(jestConfig)};
  require('jest').runCLI(argv, [projectDir]); // BUG: should be tests/unit?
}

'use strict';

/* globals WeakMap */

var isCallable = require('is-callable');
var isString = require('is-string');
var has = require('has');
var forEach = require('for-each');
var isArray = require('isarray');
var functionName = require('function.prototype.name');
var inspect = require('object-inspect');
var semver = require('semver');
var jestVersion = require('jest').getVersion();

var checkWithName = require('./helpers/checkWithName');

var withOverrides = require('./withOverrides');
var withOverride = require('./withOverride');
var withGlobal = require('./withGlobal');

var hasPrivacy = typeof WeakMap === 'function';
var wrapperMap = hasPrivacy ? new WeakMap() : /* istanbul ignore next */ null;
var modeMap = hasPrivacy ? new WeakMap() : /* istanbul ignore next */ null;

var MODE_ALL = 'all';
var MODE_SKIP = 'skip';
var MODE_ONLY = 'only';

var beforeMethods = ['beforeAll', 'beforeEach'];