Unitest

:construction: This is beta

expect

import { expect } from "https://deno.land/x/unitest@$VERSION/mod.ts";

expect("").toBe("");

Custom matcher

It provides custom matcher interface.

You can add custom matcher easy. The type is automatically extended.

import { defineExpect, jestMatcherMap } from "https://deno.land/x/unitest@$VERSION/mod.ts";

const expect = defineExpect({
  ...jestMatcherMap
  toBe100: (actual) => {
    if (actual === 100) return { pass: true };
    return {
      pass: false,
      message,
    };
  },
});

expect(1000).not.toBe100();

Power of TypeScript

Take full advantage of the power of TypeScript’s type analysis.

In the example above, the actual toBe100 takes no arguments. (It’s not variadic arguments.)

The matcher takes an actual value as its first argument. However, in the type definition, the actual value is removed. This is accomplished by TypeScript.

Let’s look at a more advanced example.

The type definition of a matcher toBeGreaterThan looks like this.

function toBeGreaterThan(
  actual: number | bigint,
  comparison: number | bigint,
) {}

toBeGreaterThan takes a number | bigint as comparison. Therefore, the actual value should also be number | bigint. Because jest separated the matcher implementation from its type definition, it was difficult to give actual a type other than any.

In this project, we use all the power of TypeScript.

The type of actual will filter the available matchers.

For example, if actual has a value of type string, only matchers with a first argument of a type compatible with string will be available.

expect("hello").toBeUndefined();
expect("world").toMatch(/hello/);

// This will result in a type error.
// expect('world').toBeGreaterThan(0)

expect(10).toBeUndefined();
expect(10).toBeGreaterThan(3);

// This will result in a type error.
// expect(10).toMatch("10")

This allows TypeScript to do some of the assertions for you.

TODO

• Implement expecter and jest default matcher (rest)
  • toHaveProperty
  • toContainEqual
  • toMatchObject
  • toMatchSnapshot
  • toMatchInlineSnapshot
  • toStrictEqual
  • toThrowErrorMatchingSnapshot
  • toThrowErrorMatchingInlineSnapshot
• Implement third party matcher
  • jest-extended
    • toBeEmpty
    • toBeOneOf
    • toBeNil
    • toSatisfy
    • toBeArray
    • toBeArrayOfSize toHaveLength
    • toIncludeAllMembers
    • toIncludeAllPartialMembers
    • toIncludeAnyMembers
    • toIncludeSameMembers
    • toSatisfyAll
    • toSatisfyAny
    • toBeBoolean
    • toBeTrue
    • toBeFalse
    • toBeDate
    • toBeValidDate
    • toBeAfter
    • toBeBefore
    • toBeAfterOrEqualTo
    • toBeBeforeOrEqualTo
    • toBeBetween
    • toBeFunction
    • toThrowWithMessage
    • toHaveBeenCalledBefore
    • toHaveBeenCalledAfter
    • toHaveBeenCalledOnce
    • toBeNumber
    • toBeNaN exists in jest
    • toBeFinite
    • toBePositive
    • toBeNegative
    • toBeEven
    • toBeOdd
    • toBeWithin
    • toBeInteger
    • toBeObject
    • toBeEmptyObject
    • toContainKey
    • toContainKeys
    • toContainAllKeys
    • toContainAnyKeys
    • toContainValue
    • toContainValues
    • toContainAllValues
    • toContainAnyValues
    • toContainEntry
    • toContainEntries
    • toContainAllEntries
    • toContainAnyEntries
    • toBeExtensible
    • toBeFrozen
    • toBeSealed
    • toResolve
    • toReject
    • toBeString
    • toBeHexadecimal
    • toBeDateString
    • toEqualCaseInsensitive
    • toStartWith
    • toEndWith
    • toInclude
    • toIncludeRepeated
    • toIncludeMultiple
    • toEqualIgnoringWhitespace
    • toBeSymbol
• Implement interface of custom matcher
• Implement it suite
• Implement describe suite

License

Copyright © 2021-present TomokiMiyauci.

Released under the MIT license