puppeteer-core
Version:
A high-level API to control headless Chrome over the DevTools Protocol
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text/typescript
/**
* @license
* Copyright 2023 Google Inc.
* SPDX-License-Identifier: Apache-2.0
*/
declare global {
interface SymbolConstructor {
/**
* A method that is used to release resources held by an object. Called by
* the semantics of the `using` statement.
*/
readonly dispose: unique symbol;
/**
* A method that is used to asynchronously release resources held by an
* object. Called by the semantics of the `await using` statement.
*/
readonly asyncDispose: unique symbol;
}
interface Disposable {
[Symbol.dispose](): void;
}
interface AsyncDisposable {
[Symbol.asyncDispose](): PromiseLike<void>;
}
}
(Symbol as any).dispose ??= Symbol('dispose');
(Symbol as any).asyncDispose ??= Symbol('asyncDispose');
/**
* @internal
*/
export const disposeSymbol: typeof Symbol.dispose = Symbol.dispose;
/**
* @internal
*/
export const asyncDisposeSymbol: typeof Symbol.asyncDispose =
Symbol.asyncDispose;
/**
* @internal
*/
export class DisposableStack {
#disposed = false;
#stack: Disposable[] = [];
/**
* Returns a value indicating whether the stack has been disposed.
*/
get disposed(): boolean {
return this.#disposed;
}
/**
* Alias for `[Symbol.dispose]()`.
*/
dispose(): void {
this[disposeSymbol]();
}
/**
* Adds a disposable resource to the top of stack, returning the resource.
* Has no effect if provided `null` or `undefined`.
*
* @param value - A `Disposable` object, `null`, or `undefined`.
* `null` and `undefined` will not be added, but will be returned.
* @returns The provided `value`.
*/
use<T extends Disposable | null | undefined>(value: T): T {
if (value && typeof value[disposeSymbol] === 'function') {
this.#stack.push(value);
}
return value;
}
/**
* Adds a non-disposable resource and a disposal callback to the top of the stack.
*
* @param value - A resource to be disposed.
* @param onDispose - A callback invoked to dispose the provided value.
* Will be invoked with `value` as the first parameter.
* @returns The provided `value`.
*/
adopt<T>(value: T, onDispose: (value: T) => void): T {
this.#stack.push({
[disposeSymbol]() {
onDispose(value);
},
});
return value;
}
/**
* Add a disposal callback to the top of the stack to be invoked when stack is disposed.
* @param onDispose - A callback to invoke when this object is disposed.
*/
defer(onDispose: () => void): void {
this.#stack.push({
[disposeSymbol]() {
onDispose();
},
});
}
/**
* Move all resources out of this stack and into a new `DisposableStack`, and
* marks this stack as disposed.
* @returns The new `DisposableStack`.
*
* @example
*
* ```ts
* class C {
* #res1: Disposable;
* #res2: Disposable;
* #disposables: DisposableStack;
* constructor() {
* // stack will be disposed when exiting constructor for any reason
* using stack = new DisposableStack();
*
* // get first resource
* this.#res1 = stack.use(getResource1());
*
* // get second resource. If this fails, both `stack` and `#res1` will be disposed.
* this.#res2 = stack.use(getResource2());
*
* // all operations succeeded, move resources out of `stack` so that
* // they aren't disposed when constructor exits
* this.#disposables = stack.move();
* }
*
* [disposeSymbol]() {
* this.#disposables.dispose();
* }
* }
* ```
*/
move(): DisposableStack {
if (this.#disposed) {
throw new ReferenceError('A disposed stack can not use anything new');
}
const stack = new DisposableStack();
stack.#stack = this.#stack;
this.#stack = [];
this.#disposed = true;
return stack;
}
/**
* Disposes each resource in the stack in last-in-first-out (LIFO) manner.
*/
[disposeSymbol](): void {
if (this.#disposed) {
return;
}
this.#disposed = true;
const errors: unknown[] = [];
for (const resource of this.#stack.reverse()) {
try {
resource[disposeSymbol]();
} catch (e) {
errors.push(e);
}
}
if (errors.length === 1) {
throw errors[0];
} else if (errors.length > 1) {
let suppressed = null;
for (const error of errors.reverse()) {
if (suppressed === null) {
suppressed = error;
} else {
suppressed = new SuppressedError(error, suppressed);
}
}
throw suppressed;
}
}
readonly [Symbol.toStringTag] = 'DisposableStack';
}
/**
* @internal
*/
export class AsyncDisposableStack {
#disposed = false;
#stack: AsyncDisposable[] = [];
/**
* Returns a value indicating whether the stack has been disposed.
*/
get disposed(): boolean {
return this.#disposed;
}
/**
* Alias for `[Symbol.asyncDispose]()`.
*/
async dispose(): Promise<void> {
await this[asyncDisposeSymbol]();
}
/**
* Adds a AsyncDisposable resource to the top of stack, returning the resource.
* Has no effect if provided `null` or `undefined`.
*
* @param value - A `AsyncDisposable` object, `null`, or `undefined`.
* `null` and `undefined` will not be added, but will be returned.
* @returns The provided `value`.
*/
use<T extends AsyncDisposable | Disposable | null | undefined>(value: T): T {
if (value) {
const asyncDispose = (value as AsyncDisposable)[asyncDisposeSymbol];
const dispose = (value as Disposable)[disposeSymbol];
if (typeof asyncDispose === 'function') {
this.#stack.push(value as AsyncDisposable);
} else if (typeof dispose === 'function') {
this.#stack.push({
[asyncDisposeSymbol]: async () => {
(value as Disposable)[disposeSymbol]();
},
});
}
}
return value;
}
/**
* Adds a non-disposable resource and a disposal callback to the top of the stack.
*
* @param value - A resource to be disposed.
* @param onDispose - A callback invoked to dispose the provided value.
* Will be invoked with `value` as the first parameter.
* @returns The provided `value`.
*/
adopt<T>(value: T, onDispose: (value: T) => Promise<void>): T {
this.#stack.push({
[asyncDisposeSymbol]() {
return onDispose(value);
},
});
return value;
}
/**
* Add a disposal callback to the top of the stack to be invoked when stack is disposed.
* @param onDispose - A callback to invoke when this object is disposed.
*/
defer(onDispose: () => Promise<void>): void {
this.#stack.push({
[asyncDisposeSymbol]() {
return onDispose();
},
});
}
/**
* Move all resources out of this stack and into a new `DisposableStack`, and
* marks this stack as disposed.
* @returns The new `AsyncDisposableStack`.
*
* @example
*
* ```ts
* class C {
* #res1: Disposable;
* #res2: Disposable;
* #disposables: DisposableStack;
* constructor() {
* // stack will be disposed when exiting constructor for any reason
* using stack = new DisposableStack();
*
* // get first resource
* this.#res1 = stack.use(getResource1());
*
* // get second resource. If this fails, both `stack` and `#res1` will be disposed.
* this.#res2 = stack.use(getResource2());
*
* // all operations succeeded, move resources out of `stack` so that
* // they aren't disposed when constructor exits
* this.#disposables = stack.move();
* }
*
* [disposeSymbol]() {
* this.#disposables.dispose();
* }
* }
* ```
*/
move(): AsyncDisposableStack {
if (this.#disposed) {
throw new ReferenceError('A disposed stack can not use anything new');
}
const stack = new AsyncDisposableStack();
stack.#stack = this.#stack;
this.#stack = [];
this.#disposed = true;
return stack;
}
/**
* Disposes each resource in the stack in last-in-first-out (LIFO) manner.
*/
async [asyncDisposeSymbol](): Promise<void> {
if (this.#disposed) {
return;
}
this.#disposed = true;
const errors: unknown[] = [];
for (const resource of this.#stack.reverse()) {
try {
await resource[asyncDisposeSymbol]();
} catch (e) {
errors.push(e);
}
}
if (errors.length === 1) {
throw errors[0];
} else if (errors.length > 1) {
let suppressed = null;
for (const error of errors.reverse()) {
if (suppressed === null) {
suppressed = error;
} else {
suppressed = new SuppressedError(error, suppressed);
}
}
throw suppressed;
}
}
readonly [Symbol.toStringTag] = 'AsyncDisposableStack';
}
/**
* @internal
* Represents an error that occurs when multiple errors are thrown during
* the disposal of resources. This class encapsulates the primary error and
* any suppressed errors that occurred subsequently.
*/
export class SuppressedError extends Error {
#error: unknown;
#suppressed: unknown;
constructor(
error: unknown,
suppressed: unknown,
message = 'An error was suppressed during disposal',
) {
super(message);
this.name = 'SuppressedError';
this.#error = error;
this.#suppressed = suppressed;
}
/**
* The primary error that occurred during disposal.
*/
get error(): unknown {
return this.#error;
}
/**
* The suppressed error i.e. the error that was suppressed
* because it occurred later in the flow after the original error.
*/
get suppressed(): unknown {
return this.#suppressed;
}
}