Class DriverManager

Manage instances of WebDriver to be used by the tests. DriverManager allows a single place where the WebDriver instance can be configured and reused. Traditionally, tests instantiate the WebDriver instance on their own, passing configurations such as the browser to use:

let driver = new Builder().withCapabilities({
  browserName: "chrome"
}).build()
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This boilerplate code then has to be copied to every test. Additionally, if the capabilities need to change (say, running against a different browser), that change must be applied to all test files.

DriverManager addresses this problem by centralizing the place whereby the configuration is done, and persists that configuration for all subsequent requests for the WebDriver instance. The configuration only needs to be set once in a "setup" file, and tests retrieve the configured instance without needing to define anything else.

A sample mocha-setup.ts file which configures DriverManager

import { DriverManager } from "@oracle/oraclejet-webdriver";

DriverManager.registerConfig({
  capabilities: new Capabilities({
    browserName: "chrome"
  })
})
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This setup test script should be run before any other tests.

$ node node_modules/mocha/bin/mocha --require=ts-node/register mocha-setup.ts other-test.spec.ts ...
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Test files are agnostic of the driver configuration, and simply get the instance by calling getDriver()

import { DriverManager } from "@oracle/oraclejet-webdriver";

describe("My test suite", function() {
  let driver: WebDriver;

  before(async function() {
    driver = await DriverManager.getDriver();
  })
  it("open a page to test", async function() {
    await driver.get("...")
  })
  after(async function() {
    await DriverManager.releaseDriver(driver);
  })
})
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Set default timeouts for WebDriver from Mocha.

When Mocha is used to start the WebDriver tests, there are two sets of timeout values--one from Mocha and one from WebDriver. This causes some confusion as the command-line argument --timeout=nnn is typically the only one set and assumed to be the only timeout value in play. However, WebDriver has its own set of timeout values whose defaults are sometimes longer than what's set for Mocha. When this happens, WebDriver may be waiting on a condition to timeout, but Mocha has errored the test because its own timeout was exceeded. To ensure that WebDriver timeout conditions are properly reported to the test runner (Mocha), its timeout values must be set to a value shorter than the runner's. This is typically done in the setup test, and set to some factor of the Mocha timeout.

Set WebDriver timeout to 1/4 of Mocha

const mochaTimeout = this.timeouts();
const wdTimeout = mochaTimeout / 4;
DriverManager.registerConfig({
  timeouts: {
    pageLoad: wdTimeout,
    script: wdTimeout,
    implicit: wdTimeout
  }
});
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