eslint-plugin-de-morgan/dist/utils/toggle-negation.d.ts

ESLint plugin for transforming negated boolean expressions via De Morgan’s laws

import { Expression } from 'estree'
import { Rule } from 'eslint'
/**
 * Toggles the negation of the given expression. The function applies the
 * following strategies in order:
 *
 * 1. If the expression is a `BinaryExpression` with a supported binary operator
 *    (`===`, `!==`, `==`, or `!=`), it returns the expression with the operator
 *    toggled.
 * 2. If the expression is a boolean literal, it returns the toggled boolean
 *    literal.
 * 3. If the expression is a `UnaryExpression` (i.e. Already negated), it will
 *    return the expression without the leading '!'.
 * 4. Otherwise, it returns the expression with a '!' prepended..
 *
 * When `canStripNegation` is false, an already negated expression keeps an
 * exact double negation (`!x` becomes `!!x`) instead of being stripped to the
 * bare operand. Stripping is only truthiness-preserving, so it is unsafe in
 * positions where the produced value itself is observable.
 *
 * @param node - The expression node to toggle negation on.
 * @param context - The ESLint rule context.
 * @param canStripNegation - Whether a leading '!' may be stripped from an
 *   already negated expression.
 * @returns The toggled expression.
 */
export declare function toggleNegation(
  node: Expression,
  context: Rule.RuleContext,
  canStripNegation?: boolean,
): string