fix: improve types

lib/test.d.ts

@@ -1,25 +1,31 @@
 interface TestOptions {
   /**
-   * The number of tests that can be run at the same time. If unspecified, subtests inherit this value from their parent.
-   * Default: 1.
+   * If a number is provided, then that many tests would run in parallel. If truthy, it would run (number of cpu cores - 1) tests in parallel. For subtests, it will be Infinity tests in parallel. If falsy, it would only run one test at a time. If unspecified, subtests inherit this value from their parent.
+   * @default false.
    */
   concurrency?: boolean | number;
 
+  /**
+   * If truthy, and the test context is configured to run only tests, then this test will be run. Otherwise, the test is skipped.
+   * @default false.
+   */
+  only?: boolean;
+
   /**
    * If truthy, the test is skipped. If a string is provided, that string is displayed in the test results as the reason for skipping the test.
-   * Default: false.
+   * @default false.
    */
   skip?: boolean | string;
 
   /**
    * If truthy, the test marked as TODO. If a string is provided, that string is displayed in the test results as the reason why the test is TODO.
-   * Default: false.
+   * @default false.
    */
   todo?: boolean | string;
 
   /**
    * A number of milliseconds the test will fail after. If unspecified, subtests inherit this value from their parent.
-   * Default: Infinity
+   * @default Infinity
    */
   timeout?: number;
 
@@ -29,40 +35,114 @@ interface TestOptions {
   signal?: AbortSignal;
 }
 
-type TestFn = (t: TestContext) => any | Promise<any>;
+type TestFn = (t: TestContext, done: (result?: any) => void) => any;
 
 export default test;
 
-export function test(name: string, options: TestOptions, fn: TestFn): void;
-export function test(name: string, fn: TestFn): void;
-export function test(options: TestOptions, fn: TestFn): void;
-export function test(fn: TestFn): void;
+/**
+ * @param name The name of the test, which is displayed when reporting test results.
+ *  Default: The name property of fn, or '<anonymous>' if fn does not have a name.
+ * @param options Configuration options for the test.
+ * @param fn The function under test. The first argument to this function is a TestContext object. If the test uses callbacks, the callback function is passed as the second argument.
+ *  Default: A no-op function.
+ * @returns A {@link Promise} resolved with `undefined` once the test completes.
+ */
+export function test(
+  name: string,
+  options: TestOptions,
+  fn: TestFn
+): Promise<void>;
+export function test(name: string, fn: TestFn): Promise<void>;
+export function test(options: TestOptions, fn: TestFn): Promise<void>;
+export function test(fn: TestFn): Promise<void>;
 
 type SuiteFn = (t: SuiteContext) => void;
 
+/**
+ * @param name The name of the suite, which is displayed when reporting test results.
+ *  Default: The name property of fn, or '<anonymous>' if fn does not have a name.
+ * @param options Configuration options for the suite. supports the same options as test([name][, options][, fn]).
+ * @param fn The function under suite declaring all subtests and subsuites. The first argument to this function is a SuiteContext object.
+ *  Default: A no-op function.
+ * @returns `undefined`
+ */
 export function describe(name: string, options: TestOptions, fn: SuiteFn): void;
 export function describe(name: string, fn: SuiteFn): void;
 export function describe(options: TestOptions, fn: SuiteFn): void;
 export function describe(fn: SuiteFn): void;
 
-type ItFn = (t: ItContext) => any | Promise<any>;
+type ItFn = (done: (result?: any) => void) => any;
 
+/**
+ * @param name The name of the test, which is displayed when reporting test results.
+ *  Default: The name property of fn, or '<anonymous>' if fn does not have a name.
+ * @param options Configuration options for the suite. supports the same options as test([name][, options][, fn]).
+ * @param fn The function under test. If the test uses callbacks, the callback function is passed as an argument.
+ *  Default: A no-op function.
+ * @returns `undefined`
+ */
 export function it(name: string, options: TestOptions, fn: ItFn): void;
 export function it(name: string, fn: ItFn): void;
 export function it(options: TestOptions, fn: ItFn): void;
 export function it(fn: ItFn): void;
 
+type HookFn = (done: (result?: any) => void) => any;
+
+/**
+ * This function is used to create a hook running before running a suite.
+ *
+ * @param fn The hook function. If the hook uses callbacks, the callback function is passed as the second argument.
+ *  Default: A no-op function.
+ * @param options Configuration options for the hook.
+ */
+export function before(fn?: HookFn, options?: HookOptions): void;
+
+/**
+ * This function is used to create a hook running after running a suite.
+ *
+ * @param fn The hook function. If the hook uses callbacks, the callback function is passed as the second argument.
+ *  Default: A no-op function.
+ * @param options Configuration options for the hook.
+ */
+export function after(fn?: HookFn, options?: HookOptions): void;
+
+/**
+ * This function is used to create a hook running before each subtest of the current suite.
+ *
+ * @param fn The hook function. If the hook uses callbacks, the callback function is passed as the second argument.
+ *  Default: A no-op function.
+ * @param options Configuration options for the hook.
+ */
+export function beforeEach(fn?: HookFn, options?: HookOptions): void;
+
+/**
+ * This function is used to create a hook running after each subtest of the current test.
+ *
+ * @param fn The hook function. If the hook uses callbacks, the callback function is passed as the second argument.
+ *  Default: A no-op function.
+ * @param options Configuration options for the hook.
+ */
+export function afterEach(fn?: HookFn, options?: HookOptions): void;
+
 /**
  * An instance of TestContext is passed to each test function in order to interact with the test runner.
  * However, the TestContext constructor is not exposed as part of the API.
  */
 declare class TestContext {
+  /**
+   * This function is used to create a hook running before each subtest of the current test.
+   */
+  public beforeEach: typeof beforeEach;
+
+  /**
+   * This function is used to create a hook running after each subtest of the current test.
+   */
+  public afterEach: typeof afterEach;
+
   /**
    * This function is used to create subtests under the current test. This function behaves in the same fashion as the top level test() function.
    */
-  public test(name: string, options: TestOptions, fn: TestFn): Promise<void>;
-  public test(name: string, fn: TestFn): Promise<void>;
-  public test(fn: TestFn): Promise<void>;
+  public test: typeof test;
 
   /**
    * This function is used to write TAP diagnostics to the output.
@@ -72,6 +152,20 @@ declare class TestContext {
    */
   public diagnostic(message: string): void;
 
+  /**
+   * The name of the test.
+   */
+  public name: string;
+
+  /**
+   * If `shouldRunOnlyTests` is truthy, the test context will only run tests that have the `only`
+   * option set. Otherwise, all tests are run. If Node.js was not started with the `--test-only`
+   * command-line option, this function is a no-op.
+   *
+   * @param shouldRunOnlyTests Whether or not to run `only` tests.
+   */
+  public runOnly(shouldRunOnlyTests: boolean): void;
+
   /**
    * This function causes the test's output to indicate the test as skipped.
    * If message is provided, it is included in the TAP output.
@@ -108,12 +202,19 @@ declare class SuiteContext {
 }
 
 /**
- * An instance of ItContext is passed to each suite function in order to interact with the test runner.
- * However, the ItContext constructor is not exposed as part of the API.
+ * Configuration options for hooks.
  */
-declare class ItContext {
+interface HookOptions {
   /**
-   * Can be used to abort test subtasks when the test has been aborted.
+   * Allows aborting an in-progress hook.
    */
-  public signal: AbortSignal;
+  signal?: AbortSignal;
+
+  /**
+   * A number of milliseconds the hook will fail after. If unspecified, subtests inherit this
+   * value from their parent.
+   *
+   * @default Infinity
+   */
+  timeout?: number;
 }