fast-check
Version:
Property based testing framework for JavaScript (like QuickCheck)
46 lines (45 loc) • 1.83 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.indexToMappedConstantMapperFor = indexToMappedConstantMapperFor;
exports.indexToMappedConstantUnmapperFor = indexToMappedConstantUnmapperFor;
function indexToMappedConstantMapperFor(entries) {
return function indexToMappedConstantMapper(choiceIndex) {
let idx = -1;
let numSkips = 0;
while (choiceIndex >= numSkips) {
numSkips += entries[++idx].num;
}
return entries[idx].build(choiceIndex - numSkips + entries[idx].num);
};
}
function buildReverseMapping(entries) {
const reverseMapping = { mapping: new Map(), negativeZeroIndex: undefined };
let choiceIndex = 0;
for (let entryIdx = 0; entryIdx !== entries.length; ++entryIdx) {
const entry = entries[entryIdx];
for (let idxInEntry = 0; idxInEntry !== entry.num; ++idxInEntry) {
const value = entry.build(idxInEntry);
if (value === 0 && 1 / value === Number.NEGATIVE_INFINITY) {
reverseMapping.negativeZeroIndex = choiceIndex;
}
else {
reverseMapping.mapping.set(value, choiceIndex);
}
++choiceIndex;
}
}
return reverseMapping;
}
function indexToMappedConstantUnmapperFor(entries) {
let reverseMapping = null;
return function indexToMappedConstantUnmapper(value) {
if (reverseMapping === null) {
reverseMapping = buildReverseMapping(entries);
}
const choiceIndex = Object.is(value, -0) ? reverseMapping.negativeZeroIndex : reverseMapping.mapping.get(value);
if (choiceIndex === undefined) {
throw new Error('Unknown value encountered cannot be built using this mapToConstant');
}
return choiceIndex;
};
}