fast-check
Version:
Property based testing framework for JavaScript (like QuickCheck)
55 lines (54 loc) • 2.05 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.LimitedShrinkArbitrary = void 0;
const Arbitrary_1 = require("../../check/arbitrary/definition/Arbitrary");
const Value_1 = require("../../check/arbitrary/definition/Value");
const Stream_1 = require("../../stream/Stream");
const ZipIterableIterators_1 = require("./helpers/ZipIterableIterators");
function* iotaFrom(startValue) {
let value = startValue;
while (true) {
yield value;
++value;
}
}
class LimitedShrinkArbitrary extends Arbitrary_1.Arbitrary {
constructor(arb, maxShrinks) {
super();
this.arb = arb;
this.maxShrinks = maxShrinks;
}
generate(mrng, biasFactor) {
const value = this.arb.generate(mrng, biasFactor);
return this.valueMapper(value, 0);
}
canShrinkWithoutContext(value) {
return this.arb.canShrinkWithoutContext(value);
}
shrink(value, context) {
if (this.isSafeContext(context)) {
return this.safeShrink(value, context.originalContext, context.length);
}
return this.safeShrink(value, undefined, 0);
}
safeShrink(value, originalContext, currentLength) {
const remaining = this.maxShrinks - currentLength;
if (remaining <= 0) {
return Stream_1.Stream.nil();
}
return new Stream_1.Stream((0, ZipIterableIterators_1.zipIterableIterators)(this.arb.shrink(value, originalContext), iotaFrom(currentLength + 1)))
.take(remaining)
.map((valueAndLength) => this.valueMapper(valueAndLength[0], valueAndLength[1]));
}
valueMapper(v, newLength) {
const context = { originalContext: v.context, length: newLength };
return new Value_1.Value(v.value, context);
}
isSafeContext(context) {
return (context != null &&
typeof context === 'object' &&
'originalContext' in context &&
'length' in context);
}
}
exports.LimitedShrinkArbitrary = LimitedShrinkArbitrary;