constructor(testerConfig = {}) {
		/**
		 * The configuration to use for this tester. Combination of the tester
		 * configuration and the default configuration.
		 * @type {Object}
		 */
		this.testerConfig = [
			sharedDefaultConfig,
			testerConfig,
			{ rules: { "rule-tester/validate-ast": "error" } },
		];

		this.linter = new Linter({ configType: "flat" });
	}
Creates a new instance of RuleTester.
@param {Object} [testerConfig] Optional, extra configuration for the tester