fast-check
Version:
Property based testing framework for JavaScript (like QuickCheck)
258 lines (257 loc) • 11.1 kB
JavaScript
import { safeFilter, safeGetTime, safeIndexOf, safeJoin, safeMap, safePush, safeToISOString, safeToString, Map, String, Symbol as StableSymbol, } from './globals.js';
const safeArrayFrom = Array.from;
const safeBufferIsBuffer = typeof Buffer !== 'undefined' ? Buffer.isBuffer : undefined;
const safeJsonStringify = JSON.stringify;
const safeNumberIsNaN = Number.isNaN;
const safeObjectKeys = Object.keys;
const safeObjectGetOwnPropertySymbols = Object.getOwnPropertySymbols;
const safeObjectGetOwnPropertyDescriptor = Object.getOwnPropertyDescriptor;
const safeObjectGetPrototypeOf = Object.getPrototypeOf;
const safeNegativeInfinity = Number.NEGATIVE_INFINITY;
const safePositiveInfinity = Number.POSITIVE_INFINITY;
export const toStringMethod = Symbol.for('fast-check/toStringMethod');
export function hasToStringMethod(instance) {
return (instance !== null &&
(typeof instance === 'object' || typeof instance === 'function') &&
toStringMethod in instance &&
typeof instance[toStringMethod] === 'function');
}
export const asyncToStringMethod = Symbol.for('fast-check/asyncToStringMethod');
export function hasAsyncToStringMethod(instance) {
return (instance !== null &&
(typeof instance === 'object' || typeof instance === 'function') &&
asyncToStringMethod in instance &&
typeof instance[asyncToStringMethod] === 'function');
}
const findSymbolNameRegex = /^Symbol\((.*)\)$/;
function getSymbolDescription(s) {
if (s.description !== undefined)
return s.description;
const m = findSymbolNameRegex.exec(String(s));
return m && m[1].length ? m[1] : null;
}
function stringifyNumber(numValue) {
switch (numValue) {
case 0:
return 1 / numValue === safeNegativeInfinity ? '-0' : '0';
case safeNegativeInfinity:
return 'Number.NEGATIVE_INFINITY';
case safePositiveInfinity:
return 'Number.POSITIVE_INFINITY';
default:
return numValue === numValue ? String(numValue) : 'Number.NaN';
}
}
function isSparseArray(arr) {
let previousNumberedIndex = -1;
for (const index in arr) {
const numberedIndex = Number(index);
if (numberedIndex !== previousNumberedIndex + 1)
return true;
previousNumberedIndex = numberedIndex;
}
return previousNumberedIndex + 1 !== arr.length;
}
export function stringifyInternal(value, previousValues, getAsyncContent) {
const currentValues = [...previousValues, value];
if (typeof value === 'object') {
if (safeIndexOf(previousValues, value) !== -1) {
return '[cyclic]';
}
}
if (hasAsyncToStringMethod(value)) {
const content = getAsyncContent(value);
if (content.state === 'fulfilled') {
return content.value;
}
}
if (hasToStringMethod(value)) {
try {
return value[toStringMethod]();
}
catch {
}
}
switch (safeToString(value)) {
case '[object Array]': {
const arr = value;
if (arr.length >= 50 && isSparseArray(arr)) {
const assignments = [];
for (const index in arr) {
if (!safeNumberIsNaN(Number(index)))
safePush(assignments, `${index}:${stringifyInternal(arr[index], currentValues, getAsyncContent)}`);
}
return assignments.length !== 0
? `Object.assign(Array(${arr.length}),{${safeJoin(assignments, ',')}})`
: `Array(${arr.length})`;
}
const stringifiedArray = safeJoin(safeMap(arr, (v) => stringifyInternal(v, currentValues, getAsyncContent)), ',');
return arr.length === 0 || arr.length - 1 in arr ? `[${stringifiedArray}]` : `[${stringifiedArray},]`;
}
case '[object BigInt]':
return `${value}n`;
case '[object Boolean]': {
const unboxedToString = value == true ? 'true' : 'false';
return typeof value === 'boolean' ? unboxedToString : `new Boolean(${unboxedToString})`;
}
case '[object Date]': {
const d = value;
return safeNumberIsNaN(safeGetTime(d)) ? `new Date(NaN)` : `new Date(${safeJsonStringify(safeToISOString(d))})`;
}
case '[object Map]':
return `new Map(${stringifyInternal(Array.from(value), currentValues, getAsyncContent)})`;
case '[object Null]':
return `null`;
case '[object Number]':
return typeof value === 'number' ? stringifyNumber(value) : `new Number(${stringifyNumber(Number(value))})`;
case '[object Object]': {
try {
const toStringAccessor = value.toString;
if (typeof toStringAccessor === 'function' && toStringAccessor !== Object.prototype.toString) {
return value.toString();
}
}
catch {
return '[object Object]';
}
const mapper = (k) => `${k === '__proto__'
? '["__proto__"]'
: typeof k === 'symbol'
? `[${stringifyInternal(k, currentValues, getAsyncContent)}]`
: safeJsonStringify(k)}:${stringifyInternal(value[k], currentValues, getAsyncContent)}`;
const stringifiedProperties = [
...(safeObjectGetPrototypeOf(value) === null ? ['__proto__:null'] : []),
...safeMap(safeObjectKeys(value), mapper),
...safeMap(safeFilter(safeObjectGetOwnPropertySymbols(value), (s) => {
const descriptor = safeObjectGetOwnPropertyDescriptor(value, s);
return descriptor && descriptor.enumerable;
}), mapper),
];
return '{' + safeJoin(stringifiedProperties, ',') + '}';
}
case '[object Set]':
return `new Set(${stringifyInternal(Array.from(value), currentValues, getAsyncContent)})`;
case '[object String]':
return typeof value === 'string' ? safeJsonStringify(value) : `new String(${safeJsonStringify(value)})`;
case '[object Symbol]': {
const s = value;
if (StableSymbol.keyFor(s) !== undefined) {
return `Symbol.for(${safeJsonStringify(StableSymbol.keyFor(s))})`;
}
const desc = getSymbolDescription(s);
if (desc === null) {
return 'Symbol()';
}
const knownSymbol = desc.startsWith('Symbol.') && StableSymbol[desc.substring(7)];
return s === knownSymbol ? desc : `Symbol(${safeJsonStringify(desc)})`;
}
case '[object Promise]': {
const promiseContent = getAsyncContent(value);
switch (promiseContent.state) {
case 'fulfilled':
return `Promise.resolve(${stringifyInternal(promiseContent.value, currentValues, getAsyncContent)})`;
case 'rejected':
return `Promise.reject(${stringifyInternal(promiseContent.value, currentValues, getAsyncContent)})`;
case 'pending':
return `new Promise(() => {/*pending*/})`;
case 'unknown':
default:
return `new Promise(() => {/*unknown*/})`;
}
}
case '[object Error]':
if (value instanceof Error) {
return `new Error(${stringifyInternal(value.message, currentValues, getAsyncContent)})`;
}
break;
case '[object Undefined]':
return `undefined`;
case '[object Int8Array]':
case '[object Uint8Array]':
case '[object Uint8ClampedArray]':
case '[object Int16Array]':
case '[object Uint16Array]':
case '[object Int32Array]':
case '[object Uint32Array]':
case '[object Float32Array]':
case '[object Float64Array]':
case '[object BigInt64Array]':
case '[object BigUint64Array]': {
if (typeof safeBufferIsBuffer === 'function' && safeBufferIsBuffer(value)) {
return `Buffer.from(${stringifyInternal(safeArrayFrom(value.values()), currentValues, getAsyncContent)})`;
}
const valuePrototype = safeObjectGetPrototypeOf(value);
const className = valuePrototype && valuePrototype.constructor && valuePrototype.constructor.name;
if (typeof className === 'string') {
const typedArray = value;
const valuesFromTypedArr = typedArray.values();
return `${className}.from(${stringifyInternal(safeArrayFrom(valuesFromTypedArr), currentValues, getAsyncContent)})`;
}
break;
}
}
try {
return value.toString();
}
catch {
return safeToString(value);
}
}
export function stringify(value) {
return stringifyInternal(value, [], () => ({ state: 'unknown', value: undefined }));
}
export function possiblyAsyncStringify(value) {
const stillPendingMarker = StableSymbol();
const pendingPromisesForCache = [];
const cache = new Map();
function createDelay0() {
let handleId = null;
const cancel = () => {
if (handleId !== null) {
clearTimeout(handleId);
}
};
const delay = new Promise((resolve) => {
handleId = setTimeout(() => {
handleId = null;
resolve(stillPendingMarker);
}, 0);
});
return { delay, cancel };
}
const unknownState = { state: 'unknown', value: undefined };
const getAsyncContent = function getAsyncContent(data) {
const cacheKey = data;
if (cache.has(cacheKey)) {
return cache.get(cacheKey);
}
const delay0 = createDelay0();
const p = asyncToStringMethod in data
? Promise.resolve().then(() => data[asyncToStringMethod]())
: data;
p.catch(() => { });
pendingPromisesForCache.push(Promise.race([p, delay0.delay]).then((successValue) => {
if (successValue === stillPendingMarker)
cache.set(cacheKey, { state: 'pending', value: undefined });
else
cache.set(cacheKey, { state: 'fulfilled', value: successValue });
delay0.cancel();
}, (errorValue) => {
cache.set(cacheKey, { state: 'rejected', value: errorValue });
delay0.cancel();
}));
cache.set(cacheKey, unknownState);
return unknownState;
};
function loop() {
const stringifiedValue = stringifyInternal(value, [], getAsyncContent);
if (pendingPromisesForCache.length === 0) {
return stringifiedValue;
}
return Promise.all(pendingPromisesForCache.splice(0)).then(loop);
}
return loop();
}
export async function asyncStringify(value) {
return Promise.resolve(possiblyAsyncStringify(value));
}