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6.1.0 • Public • Published

Verify library for UI WEB based projects


It is a class that has helpful assertion. How it works:

    await Verify.stringsAreEqual(
      () => header.getUserName(),
  1. All assertion methods have 3-4 arguments:
    • two or one argument(s) that will be compared
    • timeout - optional, during what time assertion will be wait until predicate return true (default 10 sec)
    • pollTimeout - optional, interval between pooling predicate (default 200 ms)
  2. If assert will fail it will try again after some interval during timeout time
  3. All assertion methods work with such compared arguments:
    • simple types such as string, boolean etc.
    • arrow function with function such as () => page.getUrl(). For what we HAVE TO use such construction:
      • it will bind this each time when method will be try to compare arguments
      • if you will try to use just await page.getUrl() it will take value just once and when will use obsolete value again and again without re-fetching
  4. Working with resolving promise:
    • any assertion method return Promise<void>, so you should resolve it (e.g. await Verify.numbersAreEqual(...))
    • inside arrow function you don't need resolve Promise, so fi you have function that return Promise, for example await page.getUrl(), you need to use it like () => page.getUrl()
  5. Compared arguments can be both like as arrow function

Error handling

In version 2 was added smart error handling and tests for all assertion methods. How work error handling? Let's assume that you compare one function that return number with expected number 5.

  • first tick function got webdriver error another Element will recieve this command, for example some animation still active;
  • second tick function returns 4 and timeout time is reached In that case you will get error message that two numbers are not equal, expected number, and actual result (or error) from last tick


Questions are welcome.

List of Verify methods:

  • toBeTruthy(getBoolean: BooleanSupplier): Promise<void>
  • textContains(getText: StringSupplier, getSubString: StringSupplier): Promise<void>
  • numbersAreEqual(getFirst: NumberSupplier, getSecond: NumberSupplier): Promise<void>
  • stringsAreEqual(getFirst: StringSupplier, getSecond: StringSupplier): Promise<void>
  • stringsAreNotEqual(getFirst: StringSupplier, getSecond: StringSupplier): Promise<void>
  • textNotContains(getText: Supplier<string>, substring: string): Promise<void>
  • objectsAreEqual(getObject: Supplier<object>, object: object): Promise<void>
  • greaterThan(getNumber: Supplier<number>, secondNumber: number): Promise<void>
  • lessThan(getNumber: Supplier<number>, secondNumber: number): Promise<void>
  • valueIsNotDefined<T>(getValue: Supplier<T>): Promise<void>
  • arrayIncludesSubArray(getSourceArray: Supplier<Array<string>>, subArray: Array<string>): Promise<void>
  • arrayDoesNotIncludeSubArray(getSourceArray: Supplier<Array<string>>, subArray: Array<string>): Promise<void>


Make default constants (timeout, pollTimeout) configurable.


npm i oi-verify

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