* `string` {string} * `regexp` {RegExp} * `message` {string|Error} > Stability: 1 - Experimental Expects the `string` input not to match the regular expression. This feature is currently experimental and the name might change or it might be completely removed again. ```js const assert = require('assert').strict; assert.doesNotMatch('I will fail', /fail/); // AssertionError [ERR_ASSERTION]: The input was expected to not match the ... assert.doesNotMatch(123, /pass/); // AssertionError [ERR_ASSERTION]: The "string" argument must be of type string. assert.doesNotMatch('I will pass', /different/); // OK ``` If the values do match, or if the `string` argument is of another type than `string`, an [`AssertionError`][] is thrown with a `message` property set equal to the value of the `message` parameter. If the `message` parameter is undefined, a default error message is assigned. If the `message` parameter is an instance of an [`Error`][] then it will be thrown instead of the [`AssertionError`][].