hexo/node_modules/webidl-conversions/lib/index.js

451 lines
13 KiB
JavaScript

"use strict";
function makeException(ErrorType, message, options) {
if (options.globals) {
ErrorType = options.globals[ErrorType.name];
}
return new ErrorType(`${options.context ? options.context : "Value"} ${message}.`);
}
function toNumber(value, options) {
if (typeof value === "bigint") {
throw makeException(TypeError, "is a BigInt which cannot be converted to a number", options);
}
if (!options.globals) {
return Number(value);
}
return options.globals.Number(value);
}
// Round x to the nearest integer, choosing the even integer if it lies halfway between two.
function evenRound(x) {
// There are four cases for numbers with fractional part being .5:
//
// case | x | floor(x) | round(x) | expected | x <> 0 | x % 1 | x & 1 | example
// 1 | 2n + 0.5 | 2n | 2n + 1 | 2n | > | 0.5 | 0 | 0.5 -> 0
// 2 | 2n + 1.5 | 2n + 1 | 2n + 2 | 2n + 2 | > | 0.5 | 1 | 1.5 -> 2
// 3 | -2n - 0.5 | -2n - 1 | -2n | -2n | < | -0.5 | 0 | -0.5 -> 0
// 4 | -2n - 1.5 | -2n - 2 | -2n - 1 | -2n - 2 | < | -0.5 | 1 | -1.5 -> -2
// (where n is a non-negative integer)
//
// Branch here for cases 1 and 4
if ((x > 0 && (x % 1) === +0.5 && (x & 1) === 0) ||
(x < 0 && (x % 1) === -0.5 && (x & 1) === 1)) {
return censorNegativeZero(Math.floor(x));
}
return censorNegativeZero(Math.round(x));
}
function integerPart(n) {
return censorNegativeZero(Math.trunc(n));
}
function sign(x) {
return x < 0 ? -1 : 1;
}
function modulo(x, y) {
// https://tc39.github.io/ecma262/#eqn-modulo
// Note that http://stackoverflow.com/a/4467559/3191 does NOT work for large modulos
const signMightNotMatch = x % y;
if (sign(y) !== sign(signMightNotMatch)) {
return signMightNotMatch + y;
}
return signMightNotMatch;
}
function censorNegativeZero(x) {
return x === 0 ? 0 : x;
}
function createIntegerConversion(bitLength, { unsigned }) {
let lowerBound, upperBound;
if (unsigned) {
lowerBound = 0;
upperBound = 2 ** bitLength - 1;
} else {
lowerBound = -(2 ** (bitLength - 1));
upperBound = 2 ** (bitLength - 1) - 1;
}
const twoToTheBitLength = 2 ** bitLength;
const twoToOneLessThanTheBitLength = 2 ** (bitLength - 1);
return (value, options = {}) => {
let x = toNumber(value, options);
x = censorNegativeZero(x);
if (options.enforceRange) {
if (!Number.isFinite(x)) {
throw makeException(TypeError, "is not a finite number", options);
}
x = integerPart(x);
if (x < lowerBound || x > upperBound) {
throw makeException(
TypeError,
`is outside the accepted range of ${lowerBound} to ${upperBound}, inclusive`,
options
);
}
return x;
}
if (!Number.isNaN(x) && options.clamp) {
x = Math.min(Math.max(x, lowerBound), upperBound);
x = evenRound(x);
return x;
}
if (!Number.isFinite(x) || x === 0) {
return 0;
}
x = integerPart(x);
// Math.pow(2, 64) is not accurately representable in JavaScript, so try to avoid these per-spec operations if
// possible. Hopefully it's an optimization for the non-64-bitLength cases too.
if (x >= lowerBound && x <= upperBound) {
return x;
}
// These will not work great for bitLength of 64, but oh well. See the README for more details.
x = modulo(x, twoToTheBitLength);
if (!unsigned && x >= twoToOneLessThanTheBitLength) {
return x - twoToTheBitLength;
}
return x;
};
}
function createLongLongConversion(bitLength, { unsigned }) {
const upperBound = Number.MAX_SAFE_INTEGER;
const lowerBound = unsigned ? 0 : Number.MIN_SAFE_INTEGER;
const asBigIntN = unsigned ? BigInt.asUintN : BigInt.asIntN;
return (value, options = {}) => {
let x = toNumber(value, options);
x = censorNegativeZero(x);
if (options.enforceRange) {
if (!Number.isFinite(x)) {
throw makeException(TypeError, "is not a finite number", options);
}
x = integerPart(x);
if (x < lowerBound || x > upperBound) {
throw makeException(
TypeError,
`is outside the accepted range of ${lowerBound} to ${upperBound}, inclusive`,
options
);
}
return x;
}
if (!Number.isNaN(x) && options.clamp) {
x = Math.min(Math.max(x, lowerBound), upperBound);
x = evenRound(x);
return x;
}
if (!Number.isFinite(x) || x === 0) {
return 0;
}
let xBigInt = BigInt(integerPart(x));
xBigInt = asBigIntN(bitLength, xBigInt);
return Number(xBigInt);
};
}
exports.any = value => {
return value;
};
exports.undefined = () => {
return undefined;
};
exports.boolean = value => {
return Boolean(value);
};
exports.byte = createIntegerConversion(8, { unsigned: false });
exports.octet = createIntegerConversion(8, { unsigned: true });
exports.short = createIntegerConversion(16, { unsigned: false });
exports["unsigned short"] = createIntegerConversion(16, { unsigned: true });
exports.long = createIntegerConversion(32, { unsigned: false });
exports["unsigned long"] = createIntegerConversion(32, { unsigned: true });
exports["long long"] = createLongLongConversion(64, { unsigned: false });
exports["unsigned long long"] = createLongLongConversion(64, { unsigned: true });
exports.double = (value, options = {}) => {
const x = toNumber(value, options);
if (!Number.isFinite(x)) {
throw makeException(TypeError, "is not a finite floating-point value", options);
}
return x;
};
exports["unrestricted double"] = (value, options = {}) => {
const x = toNumber(value, options);
return x;
};
exports.float = (value, options = {}) => {
const x = toNumber(value, options);
if (!Number.isFinite(x)) {
throw makeException(TypeError, "is not a finite floating-point value", options);
}
if (Object.is(x, -0)) {
return x;
}
const y = Math.fround(x);
if (!Number.isFinite(y)) {
throw makeException(TypeError, "is outside the range of a single-precision floating-point value", options);
}
return y;
};
exports["unrestricted float"] = (value, options = {}) => {
const x = toNumber(value, options);
if (isNaN(x)) {
return x;
}
if (Object.is(x, -0)) {
return x;
}
return Math.fround(x);
};
exports.DOMString = (value, options = {}) => {
if (options.treatNullAsEmptyString && value === null) {
return "";
}
if (typeof value === "symbol") {
throw makeException(TypeError, "is a symbol, which cannot be converted to a string", options);
}
const StringCtor = options.globals ? options.globals.String : String;
return StringCtor(value);
};
exports.ByteString = (value, options = {}) => {
const x = exports.DOMString(value, options);
let c;
for (let i = 0; (c = x.codePointAt(i)) !== undefined; ++i) {
if (c > 255) {
throw makeException(TypeError, "is not a valid ByteString", options);
}
}
return x;
};
exports.USVString = (value, options = {}) => {
const S = exports.DOMString(value, options);
const n = S.length;
const U = [];
for (let i = 0; i < n; ++i) {
const c = S.charCodeAt(i);
if (c < 0xD800 || c > 0xDFFF) {
U.push(String.fromCodePoint(c));
} else if (0xDC00 <= c && c <= 0xDFFF) {
U.push(String.fromCodePoint(0xFFFD));
} else if (i === n - 1) {
U.push(String.fromCodePoint(0xFFFD));
} else {
const d = S.charCodeAt(i + 1);
if (0xDC00 <= d && d <= 0xDFFF) {
const a = c & 0x3FF;
const b = d & 0x3FF;
U.push(String.fromCodePoint((2 << 15) + ((2 << 9) * a) + b));
++i;
} else {
U.push(String.fromCodePoint(0xFFFD));
}
}
}
return U.join("");
};
exports.object = (value, options = {}) => {
if (value === null || (typeof value !== "object" && typeof value !== "function")) {
throw makeException(TypeError, "is not an object", options);
}
return value;
};
const abByteLengthGetter =
Object.getOwnPropertyDescriptor(ArrayBuffer.prototype, "byteLength").get;
const sabByteLengthGetter =
typeof SharedArrayBuffer === "function" ?
Object.getOwnPropertyDescriptor(SharedArrayBuffer.prototype, "byteLength").get :
null;
function isNonSharedArrayBuffer(value) {
try {
// This will throw on SharedArrayBuffers, but not detached ArrayBuffers.
// (The spec says it should throw, but the spec conflicts with implementations: https://github.com/tc39/ecma262/issues/678)
abByteLengthGetter.call(value);
return true;
} catch {
return false;
}
}
function isSharedArrayBuffer(value) {
try {
sabByteLengthGetter.call(value);
return true;
} catch {
return false;
}
}
function isArrayBufferDetached(value) {
try {
// eslint-disable-next-line no-new
new Uint8Array(value);
return false;
} catch {
return true;
}
}
exports.ArrayBuffer = (value, options = {}) => {
if (!isNonSharedArrayBuffer(value)) {
if (options.allowShared && !isSharedArrayBuffer(value)) {
throw makeException(TypeError, "is not an ArrayBuffer or SharedArrayBuffer", options);
}
throw makeException(TypeError, "is not an ArrayBuffer", options);
}
if (isArrayBufferDetached(value)) {
throw makeException(TypeError, "is a detached ArrayBuffer", options);
}
return value;
};
const dvByteLengthGetter =
Object.getOwnPropertyDescriptor(DataView.prototype, "byteLength").get;
exports.DataView = (value, options = {}) => {
try {
dvByteLengthGetter.call(value);
} catch (e) {
throw makeException(TypeError, "is not a DataView", options);
}
if (!options.allowShared && isSharedArrayBuffer(value.buffer)) {
throw makeException(TypeError, "is backed by a SharedArrayBuffer, which is not allowed", options);
}
if (isArrayBufferDetached(value.buffer)) {
throw makeException(TypeError, "is backed by a detached ArrayBuffer", options);
}
return value;
};
// Returns the unforgeable `TypedArray` constructor name or `undefined`,
// if the `this` value isn't a valid `TypedArray` object.
//
// https://tc39.es/ecma262/#sec-get-%typedarray%.prototype-@@tostringtag
const typedArrayNameGetter = Object.getOwnPropertyDescriptor(
Object.getPrototypeOf(Uint8Array).prototype,
Symbol.toStringTag
).get;
[
Int8Array,
Int16Array,
Int32Array,
Uint8Array,
Uint16Array,
Uint32Array,
Uint8ClampedArray,
Float32Array,
Float64Array
].forEach(func => {
const { name } = func;
const article = /^[AEIOU]/u.test(name) ? "an" : "a";
exports[name] = (value, options = {}) => {
if (!ArrayBuffer.isView(value) || typedArrayNameGetter.call(value) !== name) {
throw makeException(TypeError, `is not ${article} ${name} object`, options);
}
if (!options.allowShared && isSharedArrayBuffer(value.buffer)) {
throw makeException(TypeError, "is a view on a SharedArrayBuffer, which is not allowed", options);
}
if (isArrayBufferDetached(value.buffer)) {
throw makeException(TypeError, "is a view on a detached ArrayBuffer", options);
}
return value;
};
});
// Common definitions
exports.ArrayBufferView = (value, options = {}) => {
if (!ArrayBuffer.isView(value)) {
throw makeException(TypeError, "is not a view on an ArrayBuffer or SharedArrayBuffer", options);
}
if (!options.allowShared && isSharedArrayBuffer(value.buffer)) {
throw makeException(TypeError, "is a view on a SharedArrayBuffer, which is not allowed", options);
}
if (isArrayBufferDetached(value.buffer)) {
throw makeException(TypeError, "is a view on a detached ArrayBuffer", options);
}
return value;
};
exports.BufferSource = (value, options = {}) => {
if (ArrayBuffer.isView(value)) {
if (!options.allowShared && isSharedArrayBuffer(value.buffer)) {
throw makeException(TypeError, "is a view on a SharedArrayBuffer, which is not allowed", options);
}
if (isArrayBufferDetached(value.buffer)) {
throw makeException(TypeError, "is a view on a detached ArrayBuffer", options);
}
return value;
}
if (!options.allowShared && !isNonSharedArrayBuffer(value)) {
throw makeException(TypeError, "is not an ArrayBuffer or a view on one", options);
}
if (options.allowShared && !isSharedArrayBuffer(value) && !isNonSharedArrayBuffer(value)) {
throw makeException(TypeError, "is not an ArrayBuffer, SharedArrayBuffer, or a view on one", options);
}
if (isArrayBufferDetached(value)) {
throw makeException(TypeError, "is a detached ArrayBuffer", options);
}
return value;
};
exports.DOMTimeStamp = exports["unsigned long long"];