How to use letrecBuilder method in fast-check-monorepo

Best JavaScript code snippet using fast-check-monorepo

letrec.spec.ts

Source:letrec.spec.ts

1import { letrec } from '../../../src/arbitrary/letrec';2import { LazyArbitrary } from '../../../src/arbitrary/_internals/LazyArbitrary';3import { Value } from '../../../src/check/arbitrary/definition/Value';4import { Stream } from '../../../src/stream/Stream';5import { FakeIntegerArbitrary, fakeArbitrary } from './__test-helpers__/ArbitraryHelpers';6import { fakeRandom } from './__test-helpers__/RandomHelpers';7import {8  assertGenerateEquivalentTo,9  assertProduceSameValueGivenSameSeed,10  assertProduceValuesShrinkableWithoutContext,11  assertShrinkProducesSameValueWithoutInitialContext,12} from './__test-helpers__/ArbitraryAssertions';13describe('letrec', () => {14  describe('builder', () => {15    it('should be able to construct independant arbitraries', () => {16      // Arrange17      const { instance: expectedArb1 } = fakeArbitrary();18      const { instance: expectedArb2 } = fakeArbitrary();19      // Act20      const { arb1, arb2 } = letrec((_tie) => ({21        arb1: expectedArb1,22        arb2: expectedArb2,23      }));24      // Assert25      expect(arb1).toBe(expectedArb1);26      expect(arb2).toBe(expectedArb2);27    });28    it('should not produce LazyArbitrary for no-tie constructs', () => {29      // Arrange30      const { instance: expectedArb } = fakeArbitrary();31      // Act32      const { arb } = letrec((_tie) => ({33        arb: expectedArb,34      }));35      // Assert36      expect(arb).not.toBeInstanceOf(LazyArbitrary);37      expect(arb).toBe(expectedArb);38    });39    it('should not produce LazyArbitrary for indirect tie constructs', () => {40      // Arrange / Act41      const { arb } = letrec((tie) => {42        const { instance: expectedArb, generate } = fakeArbitrary();43        generate.mockImplementation((...args) => tie('arb').generate(...args));44        return {45          // arb is an arbitrary wrapping the tie value (as fc.array)46          arb: expectedArb,47        };48      });49      // Assert50      expect(arb).not.toBeInstanceOf(LazyArbitrary);51    });52    it('should produce LazyArbitrary for direct tie constructs', () => {53      // Arrange / Act54      const { arb } = letrec((tie) => ({55        arb: tie('arb'),56      }));57      // Assert58      expect(arb).toBeInstanceOf(LazyArbitrary);59    });60    it('should be able to construct mutually recursive arbitraries', () => {61      // Arrange / Act62      const { arb1, arb2 } = letrec((tie) => ({63        arb1: tie('arb2'),64        arb2: tie('arb1'),65      }));66      // Assert67      expect(arb1).toBeDefined();68      expect(arb2).toBeDefined();69    });70    it('should apply tie correctly', () => {71      // Arrange72      const { instance: expectedArb } = fakeArbitrary();73      // Act74      const { arb1, arb2, arb3 } = letrec((tie) => ({75        arb1: tie('arb2'),76        arb2: tie('arb3'),77        arb3: expectedArb,78      }));79      // Assert80      expect(arb1).toBeInstanceOf(LazyArbitrary);81      expect(arb2).toBeInstanceOf(LazyArbitrary);82      expect(arb3).not.toBeInstanceOf(LazyArbitrary);83      expect((arb1 as any as LazyArbitrary<unknown>).underlying).toBe(arb2);84      expect((arb2 as any as LazyArbitrary<unknown>).underlying).toBe(arb3);85      expect(arb3).toBe(expectedArb);86    });87    it('should apply tie the same way for a reversed declaration', () => {88      // Arrange89      const { instance: expectedArb } = fakeArbitrary();90      // Act91      const { arb1, arb2, arb3 } = letrec((tie) => ({92        // Same scenario as 'should apply tie correctly'93        // except we declared arb3 > arb2 > arb194        // instead of arb1 > arb2 > arb395        arb3: expectedArb,96        arb2: tie('arb3'),97        arb1: tie('arb2'),98      }));99      // Assert100      expect(arb1).toBeInstanceOf(LazyArbitrary);101      expect(arb2).toBeInstanceOf(LazyArbitrary);102      expect(arb3).not.toBeInstanceOf(LazyArbitrary);103      expect((arb1 as any as LazyArbitrary<unknown>).underlying).toBe(arb2);104      expect((arb2 as any as LazyArbitrary<unknown>).underlying).toBe(arb3);105      expect(arb3).toBe(expectedArb);106    });107  });108  describe('generate', () => {109    it('should be able to delay calls to tie to generate', () => {110      // Arrange111      const biasFactor = 69;112      const { instance: simpleArb, generate } = fakeArbitrary();113      generate.mockReturnValueOnce(new Value(null, undefined));114      const { instance: mrng } = fakeRandom();115      // Act116      const { arb1 } = letrec((tie) => {117        const { instance: simpleArb2, generate: generate2 } = fakeArbitrary();118        generate2.mockImplementation((...args) => tie('arb2').generate(...args));119        return {120          arb1: simpleArb2,121          arb2: simpleArb,122        };123      });124      expect(generate).not.toHaveBeenCalled();125      arb1.generate(mrng, biasFactor);126      // Assert127      expect(generate).toHaveBeenCalledTimes(1);128      expect(generate).toHaveBeenCalledWith(mrng, biasFactor);129    });130    it('should throw on generate if tie receives an invalid parameter', () => {131      // Arrange132      const biasFactor = 42;133      const { arb1 } = letrec((tie) => ({134        arb1: tie('missing'),135      }));136      const { instance: mrng } = fakeRandom();137      // Act / Assert138      expect(() => arb1.generate(mrng, biasFactor)).toThrowErrorMatchingInlineSnapshot(139        `"Lazy arbitrary "missing" not correctly initialized"`140      );141    });142    it('should throw on generate if tie receives an invalid parameter after creation', () => {143      // Arrange144      const biasFactor = 42;145      const { arb1 } = letrec((tie) => {146        const { instance: simpleArb, generate } = fakeArbitrary();147        generate.mockImplementation((...args) => tie('missing').generate(...args));148        return {149          arb1: simpleArb,150        };151      });152      const { instance: mrng } = fakeRandom();153      // Act / Assert154      expect(() => arb1.generate(mrng, biasFactor)).toThrowErrorMatchingInlineSnapshot(155        `"Lazy arbitrary "missing" not correctly initialized"`156      );157    });158    it('should accept "reserved" keys as output of builder', () => {159      // Arrange160      const biasFactor = 42;161      const { instance: simpleArb, generate } = fakeArbitrary();162      generate.mockReturnValueOnce(new Value(null, undefined));163      const { tie } = letrec((tie) => ({164        tie: tie('__proto__'),165        ['__proto__']: tie('__defineGetter__ââ'),166        ['__defineGetter__ââ']: tie('__defineSetter__ââ'),167        ['__defineSetter__ââ']: tie('__lookupGetter__ââ'),168        ['__lookupGetter__ââ']: tie('__lookupSetter__ââ'),169        ['__lookupSetter__ââ']: tie('constructorââ'),170        ['constructorââ']: tie('hasOwnPropertyââ'),171        ['hasOwnPropertyââ']: tie('isPrototypeOfââ'),172        ['isPrototypeOfââ']: tie('propertyIsEnumerableââ'),173        ['propertyIsEnumerableââ']: tie('toLocaleStringââ'),174        ['toLocaleStringââ']: tie('toSourceââ'),175        ['toSourceââ']: tie('toStringââ'),176        ['toStringââ']: tie('valueOf'),177        ['valueOf']: simpleArb,178      }));179      const { instance: mrng } = fakeRandom();180      // Act181      expect(generate).not.toHaveBeenCalled();182      tie.generate(mrng, biasFactor);183      // Assert184      expect(generate).toHaveBeenCalledTimes(1);185      expect(generate).toHaveBeenCalledWith(mrng, biasFactor);186    });187    it('should accept builders producing objects based on Object.create(null)', () => {188      // Arrange189      const biasFactor = 42;190      const { instance: simpleArb, generate } = fakeArbitrary();191      generate.mockReturnValueOnce(new Value(null, undefined));192      const { a } = letrec<{ a: unknown }>((tie) =>193        Object.assign(Object.create(null), {194          a: tie('b'),195          b: simpleArb,196        })197      );198      const { instance: mrng } = fakeRandom();199      // Act200      expect(generate).not.toHaveBeenCalled();201      a.generate(mrng, biasFactor);202      // Assert203      expect(generate).toHaveBeenCalledTimes(1);204      expect(generate).toHaveBeenCalledWith(mrng, biasFactor);205    });206  });207  describe('canShrinkWithoutContext', () => {208    it.each`209      expectedStatus210      ${false}211      ${true}212    `('should call canShrinkWithoutContext on the targets', ({ expectedStatus }) => {213      // Arrange214      const expectedValue = Symbol();215      const { instance: simpleArb, canShrinkWithoutContext } = fakeArbitrary();216      canShrinkWithoutContext.mockReturnValueOnce(expectedStatus);217      const { arb1 } = letrec((tie) => {218        return {219          arb1: tie('arb2'),220          arb2: simpleArb,221        };222      });223      // Act224      const out = arb1.canShrinkWithoutContext(expectedValue);225      // Assert226      expect(canShrinkWithoutContext).toHaveBeenCalledTimes(1);227      expect(canShrinkWithoutContext).toHaveBeenCalledWith(expectedValue);228      expect(out).toBe(expectedStatus);229    });230    it('should throw on canShrinkWithoutContext if tie receives an invalid parameter', () => {231      // Arrange232      const expectedValue = Symbol();233      const { arb1 } = letrec((tie) => ({234        arb1: tie('missing'),235      }));236      // Act / Assert237      expect(() => arb1.canShrinkWithoutContext(expectedValue)).toThrowErrorMatchingInlineSnapshot(238        `"Lazy arbitrary "missing" not correctly initialized"`239      );240    });241  });242  describe('shrink', () => {243    it('should call shrink on the targets', () => {244      // Arrange245      const expectedValue = Symbol();246      const expectedContext = Symbol();247      const expectedStream = Stream.of(new Value(Symbol(), undefined));248      const { instance: simpleArb, shrink } = fakeArbitrary();249      shrink.mockReturnValueOnce(expectedStream);250      const { arb1 } = letrec((tie) => {251        return {252          arb1: tie('arb2'),253          arb2: simpleArb,254        };255      });256      // Act257      const out = arb1.shrink(expectedValue, expectedContext);258      // Assert259      expect(shrink).toHaveBeenCalledTimes(1);260      expect(shrink).toHaveBeenCalledWith(expectedValue, expectedContext);261      expect(out).toBe(expectedStream);262    });263    it('should throw on shrink if tie receives an invalid parameter', () => {264      // Arrange265      const expectedValue = Symbol();266      const expectedContext = Symbol();267      const { arb1 } = letrec((tie) => ({268        arb1: tie('missing'),269      }));270      // Act / Assert271      expect(() => arb1.shrink(expectedValue, expectedContext)).toThrowErrorMatchingInlineSnapshot(272        `"Lazy arbitrary "missing" not correctly initialized"`273      );274    });275  });276});277describe('letrec (integration)', () => {278  const letrecBuilder = () => {279    const { a } = letrec((tie) => ({280      a: tie('b'),281      b: tie('c'),282      c: new FakeIntegerArbitrary(),283    }));284    return a;285  };286  it('should generate the values as-if we directly called the target arbitrary', () => {287    assertGenerateEquivalentTo(letrecBuilder, () => new FakeIntegerArbitrary(), {288      isEqualContext: (c1, c2) => {289        expect(c2).toEqual(c1);290      },291    });292  });293  it('should produce the same values given the same seed', () => {294    assertProduceSameValueGivenSameSeed(letrecBuilder);295  });296  it('should produce values seen as shrinkable without any context (if underlyings do)', () => {297    assertProduceValuesShrinkableWithoutContext(letrecBuilder);298  });299  it('should be able to shrink to the same values without initial context (if underlyings do)', () => {300    assertShrinkProducesSameValueWithoutInitialContext(letrecBuilder);301  });...

Using AI Code Generation

1const { letrecBuilder } = require('fast-check');2const { letrec } = letrecBuilder();3const list = letrec((tie) => ({4    empty: {},5    cons: { head: tie('nat'), tail: tie('list') }6}));7console.log(list);8{9  "scripts": {10  },11  "dependencies": {12  }13}14    at Object.<anonymous> (test.js:8:38)15    at Module._compile (internal/modules/cjs/loader.js:1158:30)16    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1178:10)17    at Module.load (internal/modules/cjs/loader.js:1002:32)18    at Function.Module._load (internal/modules/cjs/loader.js:901:14)19    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:74:12)20const { letrecBuilder } = require('fast-check');21const { letrec } = letrecBuilder();22const list = letrec((tie) => ({23    empty: {},24    cons: { head: 0, tail: tie('list') }25}));26console.log(list);

Using AI Code Generation

1const { letrecBuilder } = require("fast-check");2const { letrec } = letrecBuilder();3const { tuple } = require("fast-check");4const { record } = require("fast-check");5const { string } = require("fast-check");6const { number } = require("fast-check");7const { constant } = require("fast-check");8const { oneof } = require("fast-check");9const { option } = require("fast-check");10const { array } = require("fast-check");11const { map } = require("fast-check");12const { set } = require("fast-check");13const { dictionary } = require("fast-check");14const { dictionaryOf } = require("fast-check");15const { object } = require("fast-check");16const { unicode } = require("fast-check");17const { unicodeJson } = require("fast-check");18const { anyJson } = require("fast-check");19const { any } = require("fast-check");20const { bigInt } = require("fast-check");21const { float } = require("fast-check");22const { integer } = require("fast-check");23const { boolean } = require("fast-check");24const { date } = require("fast-check");25const { maxSafeInteger } = require("fast-check");26const { minSafeInteger } = require("fast-check");27const { double } = require("fast-check");28const { base64 } = require("fast-check");29const { base64String } = require("fast-check");30const { hexa } = require("fast-check");31const { hexaString } = require("fast-check");32const { char } = require("fast-check");33const { ascii } = require("fast-check");34const { asciiString } = require("fast-check");35const { fullUnicode } = require("fast-check");36const { fullUnicodeString } = require("fast-check");37const { fullUnicodeJsonObject } = require("fast-check");38const { fullUnicodeJsonString } = require("fast-check");39const { fullUnicodeJson } = require("fast-check");40const { unicodeJsonObject } = require("fast-check");41const { unicodeJsonString } = require("fast-check");42const { asciiJsonObject } = require("fast-check");43const { asciiJsonString } = require("fast-check");44const { asciiJson } = require("fast-check");45const { asciiJsonObject } = require("fast-check");46const { asciiJsonString } = require("fast-check");

Using AI Code Generation

1import { letrecBuilder } from 'fast-check';2import { letrec } from 'fast-check';3import { letrec } from 'fast-check';4import { letrecBuilder } from 'fast-check';5import { letrec } from 'fast-check';6import { letrec } from 'fast-check';7import { letrecBuilder } from 'fast-check';8import { letrec } from 'fast-check';9import { letrec } from 'fast-check';10import { letrecBuilder } from 'fast-check';11import { letrec } from 'fast-check';12import { letrec } from 'fast-check';13import { letrecBuilder } from 'fast-check';14import { letrec } from 'fast-check';15import { letrec } from 'fast-check';16import { letrecBuilder } from 'fast-check';17import { letrec } from 'fast-check';18import { letrec } from 'fast-check';19import { letrecBuilder } from 'fast-check';20import { letrec } from 'fast-check';21import { letrec } from 'fast-check';22import { letrecBuilder } from 'fast-check';23import { letrec } from 'fast-check';24import { letrec } from 'fast-check';25import { letrecBuilder } from 'fast-check';26import { letrec } from 'fast-check';27import { letrec } from 'fast-check';28import { letrecBuilder } from 'fast-check';29import { letrec } from 'fast-check';30import { letrec } from 'fast-check';31import { letrecBuilder } from 'fast-check';32import { letrec } from 'fast-check';33import { letrec } from 'fast-check';

Using AI Code Generation

1const { letrecBuilder } = require('fast-check');2const builder = letrecBuilder();3const { letrec } = builder;4const gen = letrec((tie) => ({5  a: tie('b'),6  b: tie('c'),7  c: tie('a'),8}));9const { letrecBuilder } = require('fast-check');10const builder = letrecBuilder();11const { letrec } = builder;12const gen = letrec((tie) => ({13  a: tie('b'),14  b: tie('c'),15  c: tie('a'),16}));17const { letrec } = builder;18const gen = letrec((tie) => ({19  a: tie('b'),20  b: tie('c'),21  c: tie('a'),22}));23const { letrec } = builder;24const gen = letrec((tie) => ({25  a: tie('b'),26  b: tie('c'),27  c: tie('a'),28}));29const { letrec } = builder;30const gen = letrec((tie) => ({31  a: tie('b'),32  b: tie('c'),33  c: tie('a'),34}));35const { letrec } = builder;36const gen = letrec((tie) => ({37  a: tie('b'),38  b: tie('c'),39  c: tie('a'),40}));41const { letrec } = builder;42const gen = letrec((tie) => ({43  a: tie('b'),44  b: tie('c'),45  c: tie('a'),46}));47const { letrec } = builder;48const gen = letrec((tie) => ({49  a: tie('b'),50  b: tie('c'),51  c: tie('a'),52}));53const { letrec } = builder;54const gen = letrec((tie) => ({55  a: tie('b'),56  b: tie('c'),57  c: tie('a'),58}));59const { letrec } = builder;60const gen = letrec((tie) => ({61  a: tie('b'),62  b: tie('c'),63  c: tie('a'),64}));65const { letrec } = builder;

Using AI Code Generation

1const { letrecBuilder } = require('fast-check');2const { letrec } = letrecBuilder();3const arb = letrec((tie) => ({4    node: tie('node', arb => arb.array(arb.node)),5}));6arb.node.generate(mrng => mrng.nextInt(0,1000));

Using AI Code Generation

1const { letrecBuilder } = require('fast-check');2const { func, string } = require('fast-check');3const letrec = letrecBuilder();4const gen = letrec('gen', () => func(string(), gen));5const testData = gen.generate(mrng);6const { letrecBuilder } = require('fast-check-monorepo');7const { func, string } = require('fast-check');8const letrec = letrecBuilder();9const gen = letrec.rec('gen', () => func(string(), gen));10const { letrecBuilder } = require('fast-check-monorepo

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