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denoland-deno/cli/js/web/util.ts
Kitson Kelly fc4819e1e0
refactor: Event and EventTarget implementations (#4707)
Refactors Event and EventTarget so that they better encapsulate their
non-public data as well as are more forward compatible with things like
DOM Nodes.

Moves `dom_types.ts` -> `dom_types.d.ts` which was always the intention,
it was a legacy of when we used to build the types from the code and the
limitations of the compiler.  There was a lot of cruft in `dom_types`
which shouldn't have been there, and mis-alignment to the DOM standards.
This generally has been eliminated, though we still have some minor
differences from the DOM (like the removal of some deprecated
methods/properties).

Adds `DOMException`.  Strictly it shouldn't inherit from `Error`, but
most browsers provide a stack trace when one is thrown, so the behaviour
in Deno actually better matches the browser.

`Event` still doesn't log to console like it does in the browser.  I
 wanted to get this raised and that could be an enhancement later on (it
 currently doesn't either).
2020-04-11 11:42:02 -04:00

95 lines
2.2 KiB
TypeScript

// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
export type TypedArray =
| Int8Array
| Uint8Array
| Uint8ClampedArray
| Int16Array
| Uint16Array
| Int32Array
| Uint32Array
| Float32Array
| Float64Array;
// @internal
export function isTypedArray(x: unknown): x is TypedArray {
return (
x instanceof Int8Array ||
x instanceof Uint8Array ||
x instanceof Uint8ClampedArray ||
x instanceof Int16Array ||
x instanceof Uint16Array ||
x instanceof Int32Array ||
x instanceof Uint32Array ||
x instanceof Float32Array ||
x instanceof Float64Array
);
}
// @internal
export function requiredArguments(
name: string,
length: number,
required: number
): void {
if (length < required) {
const errMsg = `${name} requires at least ${required} argument${
required === 1 ? "" : "s"
}, but only ${length} present`;
throw new TypeError(errMsg);
}
}
// @internal
export function immutableDefine(
// eslint-disable-next-line @typescript-eslint/no-explicit-any
o: any,
p: string | number | symbol,
// eslint-disable-next-line @typescript-eslint/no-explicit-any
value: any
): void {
Object.defineProperty(o, p, {
value,
configurable: false,
writable: false,
});
}
// @internal
export function hasOwnProperty(obj: unknown, v: PropertyKey): boolean {
if (obj == null) {
return false;
}
return Object.prototype.hasOwnProperty.call(obj, v);
}
/** Returns whether o is iterable.
*
* @internal */
export function isIterable<T, P extends keyof T, K extends T[P]>(
o: T
): o is T & Iterable<[P, K]> {
// checks for null and undefined
if (o == null) {
return false;
}
return (
typeof ((o as unknown) as Iterable<[P, K]>)[Symbol.iterator] === "function"
);
}
// eslint-disable-next-line @typescript-eslint/no-explicit-any
interface GenericConstructor<T = any> {
prototype: T;
}
/** A helper function which ensures accessors are enumerable, as they normally
* are not. */
export function defineEnumerableProps(
Ctor: GenericConstructor,
props: string[]
): void {
for (const prop of props) {
Reflect.defineProperty(Ctor.prototype, prop, { enumerable: true });
}
}