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Diffstat (limited to 'lib/fetch/webidl.js')
| -rw-r--r-- | lib/fetch/webidl.js | 646 |
1 files changed, 646 insertions, 0 deletions
diff --git a/lib/fetch/webidl.js b/lib/fetch/webidl.js new file mode 100644 index 0000000..6fcf2ab --- /dev/null +++ b/lib/fetch/webidl.js @@ -0,0 +1,646 @@ +'use strict' + +const { types } = require('util') +const { hasOwn, toUSVString } = require('./util') + +/** @type {import('../../types/webidl').Webidl} */ +const webidl = {} +webidl.converters = {} +webidl.util = {} +webidl.errors = {} + +webidl.errors.exception = function (message) { + return new TypeError(`${message.header}: ${message.message}`) +} + +webidl.errors.conversionFailed = function (context) { + const plural = context.types.length === 1 ? '' : ' one of' + const message = + `${context.argument} could not be converted to` + + `${plural}: ${context.types.join(', ')}.` + + return webidl.errors.exception({ + header: context.prefix, + message + }) +} + +webidl.errors.invalidArgument = function (context) { + return webidl.errors.exception({ + header: context.prefix, + message: `"${context.value}" is an invalid ${context.type}.` + }) +} + +// https://webidl.spec.whatwg.org/#implements +webidl.brandCheck = function (V, I, opts = undefined) { + if (opts?.strict !== false && !(V instanceof I)) { + throw new TypeError('Illegal invocation') + } else { + return V?.[Symbol.toStringTag] === I.prototype[Symbol.toStringTag] + } +} + +webidl.argumentLengthCheck = function ({ length }, min, ctx) { + if (length < min) { + throw webidl.errors.exception({ + message: `${min} argument${min !== 1 ? 's' : ''} required, ` + + `but${length ? ' only' : ''} ${length} found.`, + ...ctx + }) + } +} + +webidl.illegalConstructor = function () { + throw webidl.errors.exception({ + header: 'TypeError', + message: 'Illegal constructor' + }) +} + +// https://tc39.es/ecma262/#sec-ecmascript-data-types-and-values +webidl.util.Type = function (V) { + switch (typeof V) { + case 'undefined': return 'Undefined' + case 'boolean': return 'Boolean' + case 'string': return 'String' + case 'symbol': return 'Symbol' + case 'number': return 'Number' + case 'bigint': return 'BigInt' + case 'function': + case 'object': { + if (V === null) { + return 'Null' + } + + return 'Object' + } + } +} + +// https://webidl.spec.whatwg.org/#abstract-opdef-converttoint +webidl.util.ConvertToInt = function (V, bitLength, signedness, opts = {}) { + let upperBound + let lowerBound + + // 1. If bitLength is 64, then: + if (bitLength === 64) { + // 1. Let upperBound be 2^53 − 1. + upperBound = Math.pow(2, 53) - 1 + + // 2. If signedness is "unsigned", then let lowerBound be 0. + if (signedness === 'unsigned') { + lowerBound = 0 + } else { + // 3. Otherwise let lowerBound be −2^53 + 1. + lowerBound = Math.pow(-2, 53) + 1 + } + } else if (signedness === 'unsigned') { + // 2. Otherwise, if signedness is "unsigned", then: + + // 1. Let lowerBound be 0. + lowerBound = 0 + + // 2. Let upperBound be 2^bitLength − 1. + upperBound = Math.pow(2, bitLength) - 1 + } else { + // 3. Otherwise: + + // 1. Let lowerBound be -2^bitLength − 1. + lowerBound = Math.pow(-2, bitLength) - 1 + + // 2. Let upperBound be 2^bitLength − 1 − 1. + upperBound = Math.pow(2, bitLength - 1) - 1 + } + + // 4. Let x be ? ToNumber(V). + let x = Number(V) + + // 5. If x is −0, then set x to +0. + if (x === 0) { + x = 0 + } + + // 6. If the conversion is to an IDL type associated + // with the [EnforceRange] extended attribute, then: + if (opts.enforceRange === true) { + // 1. If x is NaN, +∞, or −∞, then throw a TypeError. + if ( + Number.isNaN(x) || + x === Number.POSITIVE_INFINITY || + x === Number.NEGATIVE_INFINITY + ) { + throw webidl.errors.exception({ + header: 'Integer conversion', + message: `Could not convert ${V} to an integer.` + }) + } + + // 2. Set x to IntegerPart(x). + x = webidl.util.IntegerPart(x) + + // 3. If x < lowerBound or x > upperBound, then + // throw a TypeError. + if (x < lowerBound || x > upperBound) { + throw webidl.errors.exception({ + header: 'Integer conversion', + message: `Value must be between ${lowerBound}-${upperBound}, got ${x}.` + }) + } + + // 4. Return x. + return x + } + + // 7. If x is not NaN and the conversion is to an IDL + // type associated with the [Clamp] extended + // attribute, then: + if (!Number.isNaN(x) && opts.clamp === true) { + // 1. Set x to min(max(x, lowerBound), upperBound). + x = Math.min(Math.max(x, lowerBound), upperBound) + + // 2. Round x to the nearest integer, choosing the + // even integer if it lies halfway between two, + // and choosing +0 rather than −0. + if (Math.floor(x) % 2 === 0) { + x = Math.floor(x) + } else { + x = Math.ceil(x) + } + + // 3. Return x. + return x + } + + // 8. If x is NaN, +0, +∞, or −∞, then return +0. + if ( + Number.isNaN(x) || + (x === 0 && Object.is(0, x)) || + x === Number.POSITIVE_INFINITY || + x === Number.NEGATIVE_INFINITY + ) { + return 0 + } + + // 9. Set x to IntegerPart(x). + x = webidl.util.IntegerPart(x) + + // 10. Set x to x modulo 2^bitLength. + x = x % Math.pow(2, bitLength) + + // 11. If signedness is "signed" and x ≥ 2^bitLength − 1, + // then return x − 2^bitLength. + if (signedness === 'signed' && x >= Math.pow(2, bitLength) - 1) { + return x - Math.pow(2, bitLength) + } + + // 12. Otherwise, return x. + return x +} + +// https://webidl.spec.whatwg.org/#abstract-opdef-integerpart +webidl.util.IntegerPart = function (n) { + // 1. Let r be floor(abs(n)). + const r = Math.floor(Math.abs(n)) + + // 2. If n < 0, then return -1 × r. + if (n < 0) { + return -1 * r + } + + // 3. Otherwise, return r. + return r +} + +// https://webidl.spec.whatwg.org/#es-sequence +webidl.sequenceConverter = function (converter) { + return (V) => { + // 1. If Type(V) is not Object, throw a TypeError. + if (webidl.util.Type(V) !== 'Object') { + throw webidl.errors.exception({ + header: 'Sequence', + message: `Value of type ${webidl.util.Type(V)} is not an Object.` + }) + } + + // 2. Let method be ? GetMethod(V, @@iterator). + /** @type {Generator} */ + const method = V?.[Symbol.iterator]?.() + const seq = [] + + // 3. If method is undefined, throw a TypeError. + if ( + method === undefined || + typeof method.next !== 'function' + ) { + throw webidl.errors.exception({ + header: 'Sequence', + message: 'Object is not an iterator.' + }) + } + + // https://webidl.spec.whatwg.org/#create-sequence-from-iterable + while (true) { + const { done, value } = method.next() + + if (done) { + break + } + + seq.push(converter(value)) + } + + return seq + } +} + +// https://webidl.spec.whatwg.org/#es-to-record +webidl.recordConverter = function (keyConverter, valueConverter) { + return (O) => { + // 1. If Type(O) is not Object, throw a TypeError. + if (webidl.util.Type(O) !== 'Object') { + throw webidl.errors.exception({ + header: 'Record', + message: `Value of type ${webidl.util.Type(O)} is not an Object.` + }) + } + + // 2. Let result be a new empty instance of record<K, V>. + const result = {} + + if (!types.isProxy(O)) { + // Object.keys only returns enumerable properties + const keys = Object.keys(O) + + for (const key of keys) { + // 1. Let typedKey be key converted to an IDL value of type K. + const typedKey = keyConverter(key) + + // 2. Let value be ? Get(O, key). + // 3. Let typedValue be value converted to an IDL value of type V. + const typedValue = valueConverter(O[key]) + + // 4. Set result[typedKey] to typedValue. + result[typedKey] = typedValue + } + + // 5. Return result. + return result + } + + // 3. Let keys be ? O.[[OwnPropertyKeys]](). + const keys = Reflect.ownKeys(O) + + // 4. For each key of keys. + for (const key of keys) { + // 1. Let desc be ? O.[[GetOwnProperty]](key). + const desc = Reflect.getOwnPropertyDescriptor(O, key) + + // 2. If desc is not undefined and desc.[[Enumerable]] is true: + if (desc?.enumerable) { + // 1. Let typedKey be key converted to an IDL value of type K. + const typedKey = keyConverter(key) + + // 2. Let value be ? Get(O, key). + // 3. Let typedValue be value converted to an IDL value of type V. + const typedValue = valueConverter(O[key]) + + // 4. Set result[typedKey] to typedValue. + result[typedKey] = typedValue + } + } + + // 5. Return result. + return result + } +} + +webidl.interfaceConverter = function (i) { + return (V, opts = {}) => { + if (opts.strict !== false && !(V instanceof i)) { + throw webidl.errors.exception({ + header: i.name, + message: `Expected ${V} to be an instance of ${i.name}.` + }) + } + + return V + } +} + +webidl.dictionaryConverter = function (converters) { + return (dictionary) => { + const type = webidl.util.Type(dictionary) + const dict = {} + + if (type === 'Null' || type === 'Undefined') { + return dict + } else if (type !== 'Object') { + throw webidl.errors.exception({ + header: 'Dictionary', + message: `Expected ${dictionary} to be one of: Null, Undefined, Object.` + }) + } + + for (const options of converters) { + const { key, defaultValue, required, converter } = options + + if (required === true) { + if (!hasOwn(dictionary, key)) { + throw webidl.errors.exception({ + header: 'Dictionary', + message: `Missing required key "${key}".` + }) + } + } + + let value = dictionary[key] + const hasDefault = hasOwn(options, 'defaultValue') + + // Only use defaultValue if value is undefined and + // a defaultValue options was provided. + if (hasDefault && value !== null) { + value = value ?? defaultValue + } + + // A key can be optional and have no default value. + // When this happens, do not perform a conversion, + // and do not assign the key a value. + if (required || hasDefault || value !== undefined) { + value = converter(value) + + if ( + options.allowedValues && + !options.allowedValues.includes(value) + ) { + throw webidl.errors.exception({ + header: 'Dictionary', + message: `${value} is not an accepted type. Expected one of ${options.allowedValues.join(', ')}.` + }) + } + + dict[key] = value + } + } + + return dict + } +} + +webidl.nullableConverter = function (converter) { + return (V) => { + if (V === null) { + return V + } + + return converter(V) + } +} + +// https://webidl.spec.whatwg.org/#es-DOMString +webidl.converters.DOMString = function (V, opts = {}) { + // 1. If V is null and the conversion is to an IDL type + // associated with the [LegacyNullToEmptyString] + // extended attribute, then return the DOMString value + // that represents the empty string. + if (V === null && opts.legacyNullToEmptyString) { + return '' + } + + // 2. Let x be ? ToString(V). + if (typeof V === 'symbol') { + throw new TypeError('Could not convert argument of type symbol to string.') + } + + // 3. Return the IDL DOMString value that represents the + // same sequence of code units as the one the + // ECMAScript String value x represents. + return String(V) +} + +// https://webidl.spec.whatwg.org/#es-ByteString +webidl.converters.ByteString = function (V) { + // 1. Let x be ? ToString(V). + // Note: DOMString converter perform ? ToString(V) + const x = webidl.converters.DOMString(V) + + // 2. If the value of any element of x is greater than + // 255, then throw a TypeError. + for (let index = 0; index < x.length; index++) { + if (x.charCodeAt(index) > 255) { + throw new TypeError( + 'Cannot convert argument to a ByteString because the character at ' + + `index ${index} has a value of ${x.charCodeAt(index)} which is greater than 255.` + ) + } + } + + // 3. Return an IDL ByteString value whose length is the + // length of x, and where the value of each element is + // the value of the corresponding element of x. + return x +} + +// https://webidl.spec.whatwg.org/#es-USVString +webidl.converters.USVString = toUSVString + +// https://webidl.spec.whatwg.org/#es-boolean +webidl.converters.boolean = function (V) { + // 1. Let x be the result of computing ToBoolean(V). + const x = Boolean(V) + + // 2. Return the IDL boolean value that is the one that represents + // the same truth value as the ECMAScript Boolean value x. + return x +} + +// https://webidl.spec.whatwg.org/#es-any +webidl.converters.any = function (V) { + return V +} + +// https://webidl.spec.whatwg.org/#es-long-long +webidl.converters['long long'] = function (V) { + // 1. Let x be ? ConvertToInt(V, 64, "signed"). + const x = webidl.util.ConvertToInt(V, 64, 'signed') + + // 2. Return the IDL long long value that represents + // the same numeric value as x. + return x +} + +// https://webidl.spec.whatwg.org/#es-unsigned-long-long +webidl.converters['unsigned long long'] = function (V) { + // 1. Let x be ? ConvertToInt(V, 64, "unsigned"). + const x = webidl.util.ConvertToInt(V, 64, 'unsigned') + + // 2. Return the IDL unsigned long long value that + // represents the same numeric value as x. + return x +} + +// https://webidl.spec.whatwg.org/#es-unsigned-long +webidl.converters['unsigned long'] = function (V) { + // 1. Let x be ? ConvertToInt(V, 32, "unsigned"). + const x = webidl.util.ConvertToInt(V, 32, 'unsigned') + + // 2. Return the IDL unsigned long value that + // represents the same numeric value as x. + return x +} + +// https://webidl.spec.whatwg.org/#es-unsigned-short +webidl.converters['unsigned short'] = function (V, opts) { + // 1. Let x be ? ConvertToInt(V, 16, "unsigned"). + const x = webidl.util.ConvertToInt(V, 16, 'unsigned', opts) + + // 2. Return the IDL unsigned short value that represents + // the same numeric value as x. + return x +} + +// https://webidl.spec.whatwg.org/#idl-ArrayBuffer +webidl.converters.ArrayBuffer = function (V, opts = {}) { + // 1. If Type(V) is not Object, or V does not have an + // [[ArrayBufferData]] internal slot, then throw a + // TypeError. + // see: https://tc39.es/ecma262/#sec-properties-of-the-arraybuffer-instances + // see: https://tc39.es/ecma262/#sec-properties-of-the-sharedarraybuffer-instances + if ( + webidl.util.Type(V) !== 'Object' || + !types.isAnyArrayBuffer(V) + ) { + throw webidl.errors.conversionFailed({ + prefix: `${V}`, + argument: `${V}`, + types: ['ArrayBuffer'] + }) + } + + // 2. If the conversion is not to an IDL type associated + // with the [AllowShared] extended attribute, and + // IsSharedArrayBuffer(V) is true, then throw a + // TypeError. + if (opts.allowShared === false && types.isSharedArrayBuffer(V)) { + throw webidl.errors.exception({ + header: 'ArrayBuffer', + message: 'SharedArrayBuffer is not allowed.' + }) + } + + // 3. If the conversion is not to an IDL type associated + // with the [AllowResizable] extended attribute, and + // IsResizableArrayBuffer(V) is true, then throw a + // TypeError. + // Note: resizable ArrayBuffers are currently a proposal. + + // 4. Return the IDL ArrayBuffer value that is a + // reference to the same object as V. + return V +} + +webidl.converters.TypedArray = function (V, T, opts = {}) { + // 1. Let T be the IDL type V is being converted to. + + // 2. If Type(V) is not Object, or V does not have a + // [[TypedArrayName]] internal slot with a value + // equal to T’s name, then throw a TypeError. + if ( + webidl.util.Type(V) !== 'Object' || + !types.isTypedArray(V) || + V.constructor.name !== T.name + ) { + throw webidl.errors.conversionFailed({ + prefix: `${T.name}`, + argument: `${V}`, + types: [T.name] + }) + } + + // 3. If the conversion is not to an IDL type associated + // with the [AllowShared] extended attribute, and + // IsSharedArrayBuffer(V.[[ViewedArrayBuffer]]) is + // true, then throw a TypeError. + if (opts.allowShared === false && types.isSharedArrayBuffer(V.buffer)) { + throw webidl.errors.exception({ + header: 'ArrayBuffer', + message: 'SharedArrayBuffer is not allowed.' + }) + } + + // 4. If the conversion is not to an IDL type associated + // with the [AllowResizable] extended attribute, and + // IsResizableArrayBuffer(V.[[ViewedArrayBuffer]]) is + // true, then throw a TypeError. + // Note: resizable array buffers are currently a proposal + + // 5. Return the IDL value of type T that is a reference + // to the same object as V. + return V +} + +webidl.converters.DataView = function (V, opts = {}) { + // 1. If Type(V) is not Object, or V does not have a + // [[DataView]] internal slot, then throw a TypeError. + if (webidl.util.Type(V) !== 'Object' || !types.isDataView(V)) { + throw webidl.errors.exception({ + header: 'DataView', + message: 'Object is not a DataView.' + }) + } + + // 2. If the conversion is not to an IDL type associated + // with the [AllowShared] extended attribute, and + // IsSharedArrayBuffer(V.[[ViewedArrayBuffer]]) is true, + // then throw a TypeError. + if (opts.allowShared === false && types.isSharedArrayBuffer(V.buffer)) { + throw webidl.errors.exception({ + header: 'ArrayBuffer', + message: 'SharedArrayBuffer is not allowed.' + }) + } + + // 3. If the conversion is not to an IDL type associated + // with the [AllowResizable] extended attribute, and + // IsResizableArrayBuffer(V.[[ViewedArrayBuffer]]) is + // true, then throw a TypeError. + // Note: resizable ArrayBuffers are currently a proposal + + // 4. Return the IDL DataView value that is a reference + // to the same object as V. + return V +} + +// https://webidl.spec.whatwg.org/#BufferSource +webidl.converters.BufferSource = function (V, opts = {}) { + if (types.isAnyArrayBuffer(V)) { + return webidl.converters.ArrayBuffer(V, opts) + } + + if (types.isTypedArray(V)) { + return webidl.converters.TypedArray(V, V.constructor) + } + + if (types.isDataView(V)) { + return webidl.converters.DataView(V, opts) + } + + throw new TypeError(`Could not convert ${V} to a BufferSource.`) +} + +webidl.converters['sequence<ByteString>'] = webidl.sequenceConverter( + webidl.converters.ByteString +) + +webidl.converters['sequence<sequence<ByteString>>'] = webidl.sequenceConverter( + webidl.converters['sequence<ByteString>'] +) + +webidl.converters['record<ByteString, ByteString>'] = webidl.recordConverter( + webidl.converters.ByteString, + webidl.converters.ByteString +) + +module.exports = { + webidl +} |