diff options
Diffstat (limited to 'node_modules/webidl-conversions/lib')
| -rw-r--r-- | node_modules/webidl-conversions/lib/index.js | 489 |
1 files changed, 489 insertions, 0 deletions
diff --git a/node_modules/webidl-conversions/lib/index.js b/node_modules/webidl-conversions/lib/index.js new file mode 100644 index 0000000..71d394a --- /dev/null +++ b/node_modules/webidl-conversions/lib/index.js @@ -0,0 +1,489 @@ +"use strict"; + +function makeException(ErrorType, message, opts = {}) { + if (opts.globals) { + ErrorType = opts.globals[ErrorType.name]; + } + return new ErrorType(`${opts.context ? opts.context : "Value"} ${message}.`); +} + +function toNumber(value, opts = {}) { + if (!opts.globals) { + return +value; + } + if (typeof value === "bigint") { + throw opts.globals.TypeError("Cannot convert a BigInt value to a number"); + } + return opts.globals.Number(value); +} + +function type(V) { + if (V === null) { + return "Null"; + } + switch (typeof V) { + case "undefined": + return "Undefined"; + case "boolean": + return "Boolean"; + case "number": + return "Number"; + case "string": + return "String"; + case "symbol": + return "Symbol"; + case "bigint": + return "BigInt"; + case "object": + // Falls through + case "function": + // Falls through + default: + // Per ES spec, typeof returns an implemention-defined value that is not any of the existing ones for + // uncallable non-standard exotic objects. Yet Type() which the Web IDL spec depends on returns Object for + // such cases. So treat the default case as an object. + return "Object"; + } +} + +// 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, typeOpts) { + const isSigned = !typeOpts.unsigned; + + let lowerBound; + let upperBound; + if (bitLength === 64) { + upperBound = Number.MAX_SAFE_INTEGER; + lowerBound = !isSigned ? 0 : Number.MIN_SAFE_INTEGER; + } else if (!isSigned) { + lowerBound = 0; + upperBound = Math.pow(2, bitLength) - 1; + } else { + lowerBound = -Math.pow(2, bitLength - 1); + upperBound = Math.pow(2, bitLength - 1) - 1; + } + + const twoToTheBitLength = Math.pow(2, bitLength); + const twoToOneLessThanTheBitLength = Math.pow(2, bitLength - 1); + + return (V, opts = {}) => { + let x = toNumber(V, opts); + x = censorNegativeZero(x); + + if (opts.enforceRange) { + if (!Number.isFinite(x)) { + throw makeException(TypeError, "is not a finite number", opts); + } + + x = integerPart(x); + + if (x < lowerBound || x > upperBound) { + throw makeException(TypeError, + `is outside the accepted range of ${lowerBound} to ${upperBound}, inclusive`, opts); + } + + return x; + } + + if (!Number.isNaN(x) && opts.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 (isSigned && 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 (V, opts = {}) => { + if (opts === undefined) { + opts = {}; + } + + let x = toNumber(V, opts); + x = censorNegativeZero(x); + + if (opts.enforceRange) { + if (!Number.isFinite(x)) { + throw makeException(TypeError, "is not a finite number", opts); + } + + x = integerPart(x); + + if (x < lowerBound || x > upperBound) { + throw makeException(TypeError, + `is outside the accepted range of ${lowerBound} to ${upperBound}, inclusive`, opts); + } + + return x; + } + + if (!Number.isNaN(x) && opts.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 = V => { + return V; +}; + +exports.void = function () { + return undefined; +}; + +exports.boolean = function (val) { + return !!val; +}; + +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 = (V, opts) => { + const x = toNumber(V, opts); + + if (!Number.isFinite(x)) { + throw makeException(TypeError, "is not a finite floating-point value", opts); + } + + return x; +}; + +exports["unrestricted double"] = (V, opts) => { + const x = toNumber(V, opts); + + return x; +}; + +exports.float = (V, opts) => { + const x = toNumber(V, opts); + + if (!Number.isFinite(x)) { + throw makeException(TypeError, "is not a finite floating-point value", opts); + } + + 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", opts); + } + + return y; +}; + +exports["unrestricted float"] = (V, opts) => { + const x = toNumber(V, opts); + + if (isNaN(x)) { + return x; + } + + if (Object.is(x, -0)) { + return x; + } + + return Math.fround(x); +}; + +exports.DOMString = function (V, opts = {}) { + if (opts.treatNullAsEmptyString && V === null) { + return ""; + } + + if (typeof V === "symbol") { + throw makeException(TypeError, "is a symbol, which cannot be converted to a string", opts); + } + + const StringCtor = opts.globals ? opts.globals.String : String; + return StringCtor(V); +}; + +exports.ByteString = (V, opts) => { + const x = exports.DOMString(V, opts); + let c; + for (let i = 0; (c = x.codePointAt(i)) !== undefined; ++i) { + if (c > 255) { + throw makeException(TypeError, "is not a valid ByteString", opts); + } + } + + return x; +}; + +exports.USVString = (V, opts) => { + const S = exports.DOMString(V, opts); + 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 = (V, opts) => { + if (type(V) !== "Object") { + throw makeException(TypeError, "is not an object", opts); + } + + return V; +}; + +// Not exported, but used in Function and VoidFunction. + +// Neither Function nor VoidFunction is defined with [TreatNonObjectAsNull], so +// handling for that is omitted. +function convertCallbackFunction(V, opts) { + if (typeof V !== "function") { + throw makeException(TypeError, "is not a function", opts); + } + return V; +} + +const abByteLengthGetter = + Object.getOwnPropertyDescriptor(ArrayBuffer.prototype, "byteLength").get; +const sabByteLengthGetter = + Object.getOwnPropertyDescriptor(SharedArrayBuffer.prototype, "byteLength").get; + +function isNonSharedArrayBuffer(V) { + 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(V); + + return true; + } catch { + return false; + } +} + +function isSharedArrayBuffer(V) { + try { + sabByteLengthGetter.call(V); + return true; + } catch { + return false; + } +} + +function isArrayBufferDetached(V) { + try { + // eslint-disable-next-line no-new + new Uint8Array(V); + return false; + } catch { + return true; + } +} + +exports.ArrayBuffer = (V, opts = {}) => { + if (!isNonSharedArrayBuffer(V)) { + if (opts.allowShared && !isSharedArrayBuffer(V)) { + throw makeException(TypeError, "is not an ArrayBuffer or SharedArrayBuffer", opts); + } + throw makeException(TypeError, "is not an ArrayBuffer", opts); + } + if (isArrayBufferDetached(V)) { + throw makeException(TypeError, "is a detached ArrayBuffer", opts); + } + + return V; +}; + +const dvByteLengthGetter = + Object.getOwnPropertyDescriptor(DataView.prototype, "byteLength").get; +exports.DataView = (V, opts = {}) => { + try { + dvByteLengthGetter.call(V); + } catch (e) { + throw makeException(TypeError, "is not a DataView", opts); + } + + if (!opts.allowShared && isSharedArrayBuffer(V.buffer)) { + throw makeException(TypeError, "is backed by a SharedArrayBuffer, which is not allowed", opts); + } + if (isArrayBufferDetached(V.buffer)) { + throw makeException(TypeError, "is backed by a detached ArrayBuffer", opts); + } + + return V; +}; + +// 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.name; + const article = /^[AEIOU]/.test(name) ? "an" : "a"; + exports[name] = (V, opts = {}) => { + if (!ArrayBuffer.isView(V) || typedArrayNameGetter.call(V) !== name) { + throw makeException(TypeError, `is not ${article} ${name} object`, opts); + } + if (!opts.allowShared && isSharedArrayBuffer(V.buffer)) { + throw makeException(TypeError, "is a view on a SharedArrayBuffer, which is not allowed", opts); + } + if (isArrayBufferDetached(V.buffer)) { + throw makeException(TypeError, "is a view on a detached ArrayBuffer", opts); + } + + return V; + }; +}); + +// Common definitions + +exports.ArrayBufferView = (V, opts = {}) => { + if (!ArrayBuffer.isView(V)) { + throw makeException(TypeError, "is not a view on an ArrayBuffer or SharedArrayBuffer", opts); + } + + if (!opts.allowShared && isSharedArrayBuffer(V.buffer)) { + throw makeException(TypeError, "is a view on a SharedArrayBuffer, which is not allowed", opts); + } + + if (isArrayBufferDetached(V.buffer)) { + throw makeException(TypeError, "is a view on a detached ArrayBuffer", opts); + } + return V; +}; + +exports.BufferSource = (V, opts = {}) => { + if (ArrayBuffer.isView(V)) { + if (!opts.allowShared && isSharedArrayBuffer(V.buffer)) { + throw makeException(TypeError, "is a view on a SharedArrayBuffer, which is not allowed", opts); + } + + if (isArrayBufferDetached(V.buffer)) { + throw makeException(TypeError, "is a view on a detached ArrayBuffer", opts); + } + return V; + } + + if (!opts.allowShared && !isNonSharedArrayBuffer(V)) { + throw makeException(TypeError, "is not an ArrayBuffer or a view on one", opts); + } + if (opts.allowShared && !isSharedArrayBuffer(V) && !isNonSharedArrayBuffer(V)) { + throw makeException(TypeError, "is not an ArrayBuffer, SharedArrayBufer, or a view on one", opts); + } + if (isArrayBufferDetached(V)) { + throw makeException(TypeError, "is a detached ArrayBuffer", opts); + } + + return V; +}; + +exports.DOMTimeStamp = exports["unsigned long long"]; + +exports.Function = convertCallbackFunction; + +exports.VoidFunction = convertCallbackFunction; |