jest-axe.d.ts

// Types extracted from https://www.npmjs.com/package/@types/jest-axe
// because `jest-axe` depends on `@types/jest`, which we don't want
// because we use `@jest/globals`

declare module 'jest-axe' {
  import type {
    AxeResults,
    ImpactValue,
    Result,
    RunOptions,
    Spec,
  } from 'axe-core'

  export type JestAxeConfigureOptions = {
    globalOptions?: Spec | undefined
    impactLevels?: ImpactValue[]
  } & RunOptions

  /**
   * Version of the aXe verifier with defaults set.
   *
   * @remarks You can still pass additional options to this new instance;
   *          they will be merged with the defaults.
   */
  export const axe: JestAxe

  /**
   * Runs aXe on HTML.
   *
   * @param html   Raw HTML string to verify with aXe.
   * @param options   Options to run aXe.
   * @returns Promise for the results of running aXe.
   */
  export type JestAxe = (
    html: Element | string,
    options?: RunOptions,
  ) => Promise<AxeResults>

  /**
   * Creates a new aXe verifier function.
   *
   * @param options   Options to run aXe.
   * @returns New aXe verifier function.
   */
  export function configureAxe(options?: JestAxeConfigureOptions): JestAxe

  /**
   * Results from asserting whether aXe verification passed.
   */
  export type AssertionsResult = {
    /**
     * Actual checked aXe verification results.
     */
    actual: Result[]

    /**
     * @returns Message from the Jest assertion.
     */
    message(): string

    /**
     * Whether the assertion passed.
     */
    pass: boolean
  }

  /**
   * Asserts an aXe-verified result has no violations.
   *
   * @param results   aXe verification result, if not running via expect().
   * @returns Jest expectations for the aXe result.
   */
  export type IToHaveNoViolations = (
    results?: Partial<AxeResults>,
  ) => AssertionsResult

  export const toHaveNoViolations: {
    toHaveNoViolations: IToHaveNoViolations
  }
}