toMatchResult

toMatchResult is a testing concept used in various test frameworks to verify that an actual result aligns with an expected result. It functions as a matcher or assertion that compares the structure and contents of a result object against a predefined expectation. By default, it commonly performs a deep comparison, checking nested properties, but many implementations allow customization, such as ignoring certain fields, applying partial matching, or using a user-supplied comparator.

In practice, toMatchResult is used in expectation-based and assertion-based styles. Typical usage involves supplying the actual result and an expected value, for example: a test asserts that actualResult matches expectedResult. Some frameworks also allow a predicate or matcher function to describe the acceptable shape or values of the result, enabling flexible criteria beyond exact equality.

Compared with exact equality matchers, toMatchResult emphasizes the intent to validate the result of an operation rather than a byte-for-byte match. This can include tolerances for ordering, optional fields, or dynamically generated data. Because implementations vary by language and framework, the available options—such as deep vs. partial matching, field omission, or custom comparators—differ.

Common outcomes are a pass when the actual and expected results are considered equivalent by the framework, or a fail with a diff or diagnostic that highlights mismatches. Limitations include framework dependence and potential complexity when dealing with large or highly dynamic result objects.

See also: toMatch, toEqual, deepEqual, matcher, test framework.