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How to use noShrinkArbitrary method in fast-check-monorepo

Best JavaScript code snippet using fast-check-monorepo

Arbitrary.utest.spec.ts

Source:Arbitrary.utest.spec.ts

1import { Arbitrary } from '../../../../../src/check/arbitrary/definition/Arbitrary';2import { Value } from '../../../../../src/check/arbitrary/definition/Value';3import { Stream } from '../../../../../src/stream/Stream';4import * as stubRng from '../../../stubs/generators';5import { cloneMethod, hasCloneMethod } from '../../../../../src/check/symbols';6import { Random } from '../../../../../src/random/generator/Random';7const mrngNoCall = stubRng.mutable.nocall();8describe('NextArbitrary', () => {9  describe('filter', () => {10    it('should filter the values produced by the original arbitrary on generate', () => {11      // Arrange12      const expectedBiasFactor = 48;13      const generate = jest.fn();14      const canShrinkWithoutContext = jest.fn() as any as (value: unknown) => value is any;15      const shrink = jest.fn();16      const choice1 = new Value(1, Symbol());17      const choice2 = new Value(2, Symbol());18      const choice3 = new Value(3, Symbol());19      const choice4 = new Value(4, Symbol());20      generate21        .mockReturnValueOnce(choice1)22        .mockReturnValueOnce(choice2)23        .mockReturnValueOnce(choice3)24        .mockReturnValueOnce(choice4);25      class MyNextArbitrary extends Arbitrary<any> {26        generate = generate;27        canShrinkWithoutContext = canShrinkWithoutContext;28        shrink = shrink;29      }30      // Act31      const arb = new MyNextArbitrary().filter((v) => v % 3 === 0);32      const g = arb.generate(mrngNoCall, expectedBiasFactor);33      // Assert34      expect(g).toBe(choice3); // just returning the first Value that fits35      expect(generate).toHaveBeenNthCalledWith(3, mrngNoCall, expectedBiasFactor); // same Random not cloned36    });37    it('should filter the values produced by the original arbitrary on shrink', () => {38      // Arrange39      const generate = jest.fn();40      const canShrinkWithoutContext = jest.fn() as any as (value: unknown) => value is any;41      const shrink = jest.fn();42      const valueToShrink = 5;43      const contextToShrink = Symbol();44      const choice1 = new Value(1, Symbol());45      const choice2 = new Value(2, Symbol());46      const choice3 = new Value(3, Symbol());47      const choice4 = new Value(4, Symbol());48      const choice5 = new Value(6, Symbol());49      shrink.mockReturnValueOnce(Stream.of(choice1, choice2, choice3, choice4, choice5));50      class MyNextArbitrary extends Arbitrary<any> {51        generate = generate;52        canShrinkWithoutContext = canShrinkWithoutContext;53        shrink = shrink;54      }55      // Act56      const arb = new MyNextArbitrary().filter((v) => v % 3 === 0);57      const shrinks = arb.shrink(valueToShrink, contextToShrink);58      // Assert59      expect([...shrinks]).toEqual([choice3, choice5]); // just keeping values fitting the predicate60      expect(shrink).toHaveBeenCalledWith(valueToShrink, contextToShrink);61    });62    it.each`63      canShrinkWithoutContextOutput | predicateOutput | expected64      ${false}                      | ${false}        | ${false}65      ${false}                      | ${true}         | ${false}66      ${false}                      | ${false}        | ${false}67      ${true}                       | ${true}         | ${true}68    `(69      'should check underlying arbitrary then predicate to know if the value could have been generated',70      ({ canShrinkWithoutContextOutput, predicateOutput, expected }) => {71        // Arrange72        const requestedValue = Symbol();73        const generate = jest.fn();74        const canShrinkWithoutContext = jest.fn();75        const shrink = jest.fn();76        const predicate = jest.fn();77        class MyNextArbitrary extends Arbitrary<any> {78          generate = generate;79          canShrinkWithoutContext = canShrinkWithoutContext as any as (value: unknown) => value is any;80          shrink = shrink;81        }82        canShrinkWithoutContext.mockReturnValueOnce(canShrinkWithoutContextOutput);83        predicate.mockReturnValueOnce(predicateOutput);84        // Act85        const arb = new MyNextArbitrary().filter(predicate);86        const out = arb.canShrinkWithoutContext(requestedValue);87        // Assert88        expect(out).toBe(expected);89        expect(canShrinkWithoutContext).toHaveBeenCalledWith(requestedValue);90        if (canShrinkWithoutContextOutput) {91          expect(predicate).toHaveBeenCalledWith(requestedValue);92        } else {93          expect(predicate).not.toHaveBeenCalledWith(requestedValue);94          expect(predicate).not.toHaveBeenCalled();95        }96      }97    );98  });99  describe('map', () => {100    it('should map the values produced by the original arbitrary on generate', () => {101      // Arrange102      const expectedBiasFactor = 48;103      const generate = jest.fn();104      const canShrinkWithoutContext = jest.fn() as any as (value: unknown) => value is any;105      const shrink = jest.fn();106      const choice = new Value(1, Symbol());107      generate.mockReturnValueOnce(choice);108      class MyNextArbitrary extends Arbitrary<any> {109        generate = generate;110        canShrinkWithoutContext = canShrinkWithoutContext;111        shrink = shrink;112      }113      // Act114      const arb = new MyNextArbitrary().map((v) => String(v));115      const g = arb.generate(mrngNoCall, expectedBiasFactor);116      // Assert117      expect(g.value).toBe(String(choice.value)); // value has been mapped118      expect(generate).toHaveBeenCalledWith(mrngNoCall, expectedBiasFactor);119    });120    it('should preserve cloneable capabilities for mapped values on generate', () => {121      // Arrange122      const expectedBiasFactor = 48;123      const generate = jest.fn();124      const canShrinkWithoutContext = jest.fn() as any as (value: unknown) => value is any;125      const shrink = jest.fn();126      const choice = new Value({ source: 1, [cloneMethod]: () => choice.value_ }, Symbol());127      generate.mockReturnValueOnce(choice);128      class MyNextArbitrary extends Arbitrary<any> {129        generate = generate;130        canShrinkWithoutContext = canShrinkWithoutContext;131        shrink = shrink;132      }133      // Act134      const arb = new MyNextArbitrary().map((v) => ({ stringValue: String(v.source) }));135      const g = arb.generate(mrngNoCall, expectedBiasFactor);136      // Assert137      expect(g.value.stringValue).toBe(String(choice.value.source)); // value has been mapped138      expect(g.hasToBeCloned).toBe(true); // clone has been preserved on Value139      expect(hasCloneMethod(g.value)).toBe(true); // clone has been preserved on the instance140      expect(generate).toHaveBeenCalledWith(mrngNoCall, expectedBiasFactor);141    });142    it('should not alter the mapped value if already cloneable on generate', () => {143      // Arrange144      const expectedBiasFactor = 48;145      const generate = jest.fn();146      const canShrinkWithoutContext = jest.fn() as any as (value: unknown) => value is any;147      const shrink = jest.fn();148      const choice = new Value({ source: 1, [cloneMethod]: () => choice.value_ }, Symbol());149      const mappedClone = jest.fn();150      const mapped = { source: 42, [cloneMethod]: mappedClone };151      generate.mockReturnValueOnce(choice);152      class MyNextArbitrary extends Arbitrary<any> {153        generate = generate;154        canShrinkWithoutContext = canShrinkWithoutContext;155        shrink = shrink;156      }157      // Act158      const arb = new MyNextArbitrary().map((_v) => mapped); // mapped already comes with clone capacities159      const g = arb.generate(mrngNoCall, expectedBiasFactor);160      // Assert161      expect(g.value_).toBe(mapped); // value has been mapped162      expect(g.value_.source).toBe(mapped.source); // value has been mapped and value not altered163      expect(g.value_[cloneMethod]).toBe(mapped[cloneMethod]); // value has been mapped and clone method has been preserved164      expect(g.hasToBeCloned).toBe(true); // clone has been preserved on Value165      expect(hasCloneMethod(g.value_)).toBe(true); // clone has been preserved on the instance166      expect(generate).toHaveBeenCalledWith(mrngNoCall, expectedBiasFactor);167    });168    it('should properly shrink output of generate by calling back shrink with the right context', () => {169      // Arrange170      const expectedBiasFactor = 42;171      const generate = jest.fn();172      const canShrinkWithoutContext = jest.fn() as any as (value: unknown) => value is any;173      const shrink = jest.fn();174      const source = new Value(69, Symbol());175      generate.mockReturnValueOnce(source);176      const choice1 = new Value(1, Symbol());177      const choice2 = new Value(2, Symbol());178      const choice3 = new Value(3, Symbol());179      shrink.mockReturnValueOnce(Stream.of(choice1, choice2, choice3));180      class MyNextArbitrary extends Arbitrary<any> {181        generate = generate;182        canShrinkWithoutContext = canShrinkWithoutContext;183        shrink = shrink;184      }185      // Act186      const arb = new MyNextArbitrary().map((v) => String(v));187      const g = arb.generate(mrngNoCall, expectedBiasFactor);188      const shrinks = arb.shrink(g.value, g.context);189      // Assert190      expect([...shrinks].map((s) => s.value)).toEqual(['1', '2', '3']); // just mapping values191      expect(shrink).toHaveBeenCalledWith(source.value, source.context);192    });193    it('should properly shrink output of shrink by calling back shrink with the right context', () => {194      // Arrange195      const expectedBiasFactor = 42;196      const generate = jest.fn();197      const canShrinkWithoutContext = jest.fn() as any as (value: unknown) => value is any;198      const shrink = jest.fn();199      const source = new Value(69, Symbol());200      generate.mockReturnValueOnce(source);201      const choice1 = new Value(1, Symbol());202      const choice2 = new Value(2, Symbol());203      const choice3 = new Value(3, Symbol());204      shrink.mockReturnValueOnce(Stream.of(choice1, choice2, choice3));205      const choice21 = new Value(21, Symbol());206      const choice22 = new Value(22, Symbol());207      shrink.mockReturnValueOnce(Stream.of(choice21, choice22));208      class MyNextArbitrary extends Arbitrary<any> {209        generate = generate;210        canShrinkWithoutContext = canShrinkWithoutContext;211        shrink = shrink;212      }213      // Act214      const arb = new MyNextArbitrary().map((v) => String(v));215      const g = arb.generate(mrngNoCall, expectedBiasFactor);216      const shrinksGen1 = arb.shrink(g.value, g.context);217      const mappedChoice2 = shrinksGen1.getNthOrLast(1)!;218      const shrinksGen2 = arb.shrink(mappedChoice2.value, mappedChoice2.context);219      // Assert220      expect([...shrinksGen2].map((s) => s.value)).toEqual(['21', '22']); // just mapping values221      expect(shrink).toHaveBeenCalledWith(source.value, source.context);222      expect(shrink).toHaveBeenCalledWith(choice2.value, choice2.context);223    });224    it('should preserve cloneable capabilities for mapped values on shrink', () => {225      // Arrange226      const expectedBiasFactor = 48;227      const generate = jest.fn();228      const canShrinkWithoutContext = jest.fn() as any as (value: unknown) => value is any;229      const shrink = jest.fn();230      const source = new Value({ source: 1, [cloneMethod]: () => source.value_ }, Symbol());231      generate.mockReturnValueOnce(source);232      const choice1 = new Value({ source: 2, [cloneMethod]: () => choice1.value_ }, Symbol());233      const choice2 = new Value({ source: 2, [cloneMethod]: () => choice2.value_ }, Symbol());234      shrink.mockReturnValueOnce(Stream.of(choice1, choice2));235      class MyNextArbitrary extends Arbitrary<any> {236        generate = generate;237        canShrinkWithoutContext = canShrinkWithoutContext;238        shrink = shrink;239      }240      // Act241      const arb = new MyNextArbitrary().map((v) => ({ stringValue: String(v.source) }));242      const g = arb.generate(mrngNoCall, expectedBiasFactor);243      const shrinks = arb.shrink(g.value, g.context);244      const shrinksValues = [...shrinks];245      // Assert246      expect(shrinksValues).toHaveLength(2);247      expect(shrinksValues[0].hasToBeCloned).toBe(true); // clone has been preserved on Value248      expect(shrinksValues[1].hasToBeCloned).toBe(true);249      expect(hasCloneMethod(shrinksValues[0].value)).toBe(true); // clone has been preserved on the instance250      expect(hasCloneMethod(shrinksValues[1].value)).toBe(true);251    });252    it('should always return false for canShrinkWithoutContext when not provided any unmapper function', () => {253      // Arrange254      const generate = jest.fn();255      const canShrinkWithoutContext = jest.fn();256      const shrink = jest.fn();257      class MyNextArbitrary extends Arbitrary<any> {258        generate = generate;259        canShrinkWithoutContext = canShrinkWithoutContext as any as (value: unknown) => value is any;260        shrink = shrink;261      }262      // Act263      const arb = new MyNextArbitrary().map(() => '');264      const out = arb.canShrinkWithoutContext('');265      // Assert266      expect(out).toBe(false);267      expect(canShrinkWithoutContext).not.toHaveBeenCalled();268    });269    it('should return empty stream when shrinking without any context and not provided any unmapper function', () => {270      // Arrange271      const generate = jest.fn();272      const canShrinkWithoutContext = jest.fn();273      const shrink = jest.fn();274      class MyNextArbitrary extends Arbitrary<any> {275        generate = generate;276        canShrinkWithoutContext = canShrinkWithoutContext as any as (value: unknown) => value is any;277        shrink = shrink;278      }279      // Act280      const arb = new MyNextArbitrary().map(() => '');281      const shrinks = arb.shrink('', undefined);282      // Assert283      expect([...shrinks]).toHaveLength(0);284      expect(shrink).not.toHaveBeenCalled();285      expect(canShrinkWithoutContext).not.toHaveBeenCalled();286    });287    it.each`288      outputCanGenerate289      ${false}290      ${true}291    `(292      'should try to unmap the value then call source arbitrary on canShrinkWithoutContext when provided a successful unmapper function',293      ({ outputCanGenerate }) => {294        // Arrange295        const generate = jest.fn();296        const canShrinkWithoutContext = jest.fn().mockReturnValue(outputCanGenerate);297        const shrink = jest.fn();298        const originalValue = Symbol();299        const unmapperOutput = Symbol();300        const unmapper = jest.fn().mockReturnValue(unmapperOutput);301        class MyNextArbitrary extends Arbitrary<any> {302          generate = generate;303          canShrinkWithoutContext = canShrinkWithoutContext as any as (value: unknown) => value is any;304          shrink = shrink;305        }306        // Act307        const arb = new MyNextArbitrary().map(() => Symbol(), unmapper);308        const out = arb.canShrinkWithoutContext(originalValue);309        // Assert310        expect(out).toBe(outputCanGenerate);311        expect(unmapper).toHaveBeenCalledTimes(1);312        expect(unmapper).toHaveBeenCalledWith(originalValue);313        expect(canShrinkWithoutContext).toHaveBeenCalledTimes(1);314        expect(canShrinkWithoutContext).toHaveBeenCalledWith(unmapperOutput);315      }316    );317    it('should try to unmap the value and stop on error in case of failing unmapper function', () => {318      // Arrange319      const generate = jest.fn();320      const canShrinkWithoutContext = jest.fn();321      const shrink = jest.fn();322      const originalValue = Symbol();323      const unmapper = jest.fn().mockImplementation(() => {324        throw new Error('Unable to unmap such value');325      });326      class MyNextArbitrary extends Arbitrary<any> {327        generate = generate;328        canShrinkWithoutContext = canShrinkWithoutContext as any as (value: unknown) => value is any;329        shrink = shrink;330      }331      // Act332      const arb = new MyNextArbitrary().map(() => Symbol(), unmapper);333      const out = arb.canShrinkWithoutContext(originalValue);334      // Assert335      expect(out).toBe(false);336      expect(unmapper).toHaveBeenCalledTimes(1);337      expect(unmapper).toHaveBeenCalledWith(originalValue);338      expect(canShrinkWithoutContext).not.toHaveBeenCalled();339    });340    it('should return a mapped version of the stream produced by the source arbitrary for the unmapped value when provided an unmapper function', () => {341      // Arrange342      const expectedStreamValuesFromSource = Stream.of(343        new Value('titi', undefined),344        new Value('toto', undefined),345        new Value('tutu', undefined)346      );347      const generate = jest.fn();348      const canShrinkWithoutContext = jest.fn();349      const shrink = jest.fn().mockReturnValueOnce(expectedStreamValuesFromSource);350      const originalValue = Symbol();351      const unmapperOutput = 'tata';352      const unmapper = jest.fn().mockReturnValue('tata');353      class MyNextArbitrary extends Arbitrary<any> {354        generate = generate;355        canShrinkWithoutContext = canShrinkWithoutContext as any as (value: unknown) => value is any;356        shrink = shrink;357      }358      // Act359      const arb = new MyNextArbitrary().map((tag) => Symbol.for(tag), unmapper);360      const shrinks = [...arb.shrink(originalValue, undefined)];361      // Assert362      expect(shrinks.map((s) => s.value)).toEqual([Symbol.for('titi'), Symbol.for('toto'), Symbol.for('tutu')]);363      expect(unmapper).toHaveBeenCalledTimes(1);364      expect(unmapper).toHaveBeenCalledWith(originalValue);365      expect(shrink).toHaveBeenCalledTimes(1);366      expect(shrink).toHaveBeenCalledWith(unmapperOutput, undefined);367    });368  });369  describe('chain', () => {370    it('should chain the values produced by the original arbitrary on generate', () => {371      // Arrange372      const expectedBiasFactor = 48;373      const generate = jest.fn();374      const canShrinkWithoutContext = jest.fn() as any as (value: unknown) => value is any;375      const shrink = jest.fn();376      const choiceRoot = new Value(1, Symbol());377      generate.mockReturnValueOnce(choiceRoot);378      const generateChained = jest.fn();379      const canShrinkWithoutContextChained = jest.fn() as any as (value: unknown) => value is any;380      const shrinkChained = jest.fn();381      const choiceChained = new Value(50, Symbol());382      generateChained.mockReturnValueOnce(choiceChained);383      class MyNextArbitrary extends Arbitrary<any> {384        generate = generate;385        canShrinkWithoutContext = canShrinkWithoutContext;386        shrink = shrink;387      }388      class MyNextChainedArbitrary extends Arbitrary<any> {389        generate = generateChained;390        canShrinkWithoutContext = canShrinkWithoutContextChained;391        shrink = shrinkChained;392      }393      const chainer = jest.fn();394      chainer.mockReturnValueOnce(new MyNextChainedArbitrary());395      // Act396      const arb = new MyNextArbitrary().chain(chainer);397      const g = arb.generate(mrngNoCall, expectedBiasFactor);398      // Assert399      expect(g.value).toBe(choiceChained.value); // value has been chained400      expect(generate).toHaveBeenCalledWith(mrngNoCall, expectedBiasFactor); // the two calls to generate401      expect(generateChained).toHaveBeenCalledWith(mrngNoCall, expectedBiasFactor); // they share the same Random402      expect(chainer).toHaveBeenCalledWith(choiceRoot.value); // chainer was called with output of generate403    });404    it('should properly shrink output of generate by calling back shrink with the right context', () => {405      // Arrange406      const expectedBiasFactor = 48;407      const generate = jest.fn();408      const canShrinkWithoutContext = jest.fn() as any as (value: unknown) => value is any;409      const shrink = jest.fn();410      const choiceRoot = new Value(1, Symbol());411      generate.mockReturnValueOnce(choiceRoot);412      const shrinkRoot1 = new Value(10, Symbol());413      const shrinkRoot2 = new Value(11, Symbol());414      const shrinkRoot3 = new Value(15, Symbol());415      shrink.mockReturnValueOnce(Stream.of(shrinkRoot1, shrinkRoot2, shrinkRoot3));416      const generateChained = jest.fn();417      const canShrinkWithoutContextChained = jest.fn() as any as (value: unknown) => value is any;418      const shrinkChained = jest.fn();419      const choiceChained = new Value(50, Symbol());420      const choiceShrink1Chained = new Value(58, Symbol()); // chain will be called for each sub-shrink of root421      const choiceShrink2Chained = new Value(57, Symbol());422      const choiceShrink3Chained = new Value(16, Symbol());423      generateChained424        .mockReturnValueOnce(choiceChained)425        .mockReturnValueOnce(choiceShrink1Chained)426        .mockReturnValueOnce(choiceShrink2Chained)427        .mockReturnValueOnce(choiceShrink3Chained);428      const shrinkChained1 = new Value(25, Symbol());429      const shrinkChained2 = new Value(51, Symbol());430      shrinkChained.mockReturnValueOnce(Stream.of(shrinkChained1, shrinkChained2));431      class MyNextArbitrary extends Arbitrary<any> {432        generate = generate;433        canShrinkWithoutContext = canShrinkWithoutContext;434        shrink = shrink;435      }436      class MyNextChainedArbitrary extends Arbitrary<any> {437        generate = generateChained;438        canShrinkWithoutContext = canShrinkWithoutContextChained;439        shrink = shrinkChained;440      }441      const chainer = jest.fn();442      chainer.mockReturnValue(new MyNextChainedArbitrary());443      // Act444      const arb = new MyNextArbitrary().chain(chainer);445      const g = arb.generate(mrngNoCall, expectedBiasFactor);446      const shrinks = arb.shrink(g.value, g.context);447      // Assert448      expect([...shrinks].map((v) => v.value)).toEqual([449        choiceShrink1Chained.value,450        choiceShrink2Chained.value,451        choiceShrink3Chained.value,452        shrinkChained1.value,453        shrinkChained2.value,454      ]); // shrink of source chained, then the one of original chained455      expect(generateChained).toHaveBeenNthCalledWith(4, expect.any(Random), expectedBiasFactor); // sub-sequent calls re-use the original bias456      expect(chainer).toHaveBeenCalledWith(choiceRoot.value); // original call457      expect(chainer).toHaveBeenCalledWith(shrinkRoot1.value); // chained during shrink458      expect(chainer).toHaveBeenCalledWith(shrinkRoot2.value); // chained during shrink459      expect(chainer).toHaveBeenCalledWith(shrinkRoot3.value); // chained during shrink460    });461    it('should properly shrink output of shrink by calling back shrink with the right context', () => {462      // Arrange463      const expectedBiasFactor = 48;464      const generate = jest.fn();465      const canShrinkWithoutContext = jest.fn() as any as (value: unknown) => value is any;466      const shrink = jest.fn();467      const choiceRoot = new Value(1, Symbol());468      generate.mockReturnValueOnce(choiceRoot);469      const shrinkRoot1 = new Value(10, Symbol());470      const shrinkRoot2 = new Value(11, Symbol()); // will not be iterated (getNthOrLast(0))471      const shrinkRoot3 = new Value(15, Symbol()); // will not be iterated (getNthOrLast(0))472      shrink.mockReturnValueOnce(Stream.of(shrinkRoot1, shrinkRoot2, shrinkRoot3));473      const shrinkRoot11 = new Value(310, Symbol());474      shrink.mockReturnValueOnce(Stream.of(shrinkRoot11));475      const generateChained = jest.fn();476      const canShrinkWithoutContextChained = jest.fn() as any as (value: unknown) => value is any;477      const shrinkChained = jest.fn();478      const choiceChained = new Value(50, Symbol());479      const choiceShrink1Chained = new Value(58, Symbol()); // chain will be called for each iterated sub-shrink of root (->10)480      const choiceShrink2Chained = new Value(57, Symbol()); // ->310 - 11 and 15 will not be retrieved (getNthOrLast(0))481      generateChained482        .mockReturnValueOnce(choiceChained)483        .mockReturnValueOnce(choiceShrink1Chained)484        .mockReturnValueOnce(choiceShrink2Chained);485      const shrinkChained1 = new Value(25, Symbol());486      const shrinkChained2 = new Value(51, Symbol());487      shrinkChained.mockReturnValueOnce(Stream.of(shrinkChained1, shrinkChained2));488      const shrinkChained11 = new Value(125, Symbol());489      const shrinkChained12 = new Value(151, Symbol());490      shrinkChained.mockReturnValueOnce(Stream.of(shrinkChained11, shrinkChained12));491      class MyNextArbitrary extends Arbitrary<any> {492        generate = generate;493        canShrinkWithoutContext = canShrinkWithoutContext;494        shrink = shrink;495      }496      class MyNextChainedArbitrary extends Arbitrary<any> {497        generate = generateChained;498        canShrinkWithoutContext = canShrinkWithoutContextChained;499        shrink = shrinkChained;500      }501      const chainer = jest.fn();502      chainer.mockReturnValue(new MyNextChainedArbitrary());503      // Act504      const arb = new MyNextArbitrary().chain(chainer);505      const g = arb.generate(mrngNoCall, expectedBiasFactor);506      const firstShrunkValue = arb.shrink(g.value, g.context).getNthOrLast(0)!;507      const shrinks = arb.shrink(firstShrunkValue.value, firstShrunkValue.context);508      // Assert509      expect([...shrinks].map((v) => v.value)).toEqual([510        choiceShrink2Chained.value,511        shrinkChained11.value,512        shrinkChained12.value,513      ]);514      expect(generateChained).toHaveBeenNthCalledWith(2, expect.any(Random), expectedBiasFactor); // sub-sequent calls re-use the original bias515      expect(chainer).toHaveBeenCalledWith(choiceRoot.value); // original call516      expect(chainer).toHaveBeenCalledWith(shrinkRoot1.value); // chained during shrink517      expect(chainer).not.toHaveBeenCalledWith(shrinkRoot2.value); // chained during shrink (skipped due to getNthOrLast(0)518      expect(chainer).not.toHaveBeenCalledWith(shrinkRoot3.value); // chained during shrink (skipped due to getNthOrLast(0)519      expect(chainer).toHaveBeenCalledWith(shrinkRoot11.value); // chained during second shrink (returned choiceShrink2Chained)520    });521    it('should stop shrink on source if it exhausted it once', () => {522      // Arrange523      const expectedBiasFactor = 48;524      const generate = jest.fn();525      const canShrinkWithoutContext = jest.fn() as any as (value: unknown) => value is any;526      const shrink = jest.fn();527      const choiceRoot = new Value(1, Symbol());528      generate.mockReturnValueOnce(choiceRoot);529      const shrinkRoot1 = new Value(10, Symbol());530      const shrinkRoot2 = new Value(11, Symbol());531      shrink.mockReturnValueOnce(Stream.of(shrinkRoot1, shrinkRoot2));532      const generateChained = jest.fn();533      const canShrinkWithoutContextChained = jest.fn() as any as (value: unknown) => value is any;534      const shrinkChained = jest.fn();535      const choiceChained = new Value(50, Symbol());536      const choiceShrink1Chained = new Value(58, Symbol());537      const choiceShrink2Chained = new Value(57, Symbol());538      generateChained539        .mockReturnValueOnce(choiceChained)540        .mockReturnValueOnce(choiceShrink1Chained)541        .mockReturnValueOnce(choiceShrink2Chained);542      const shrinkChained1 = new Value(25, Symbol());543      const shrinkChained2 = new Value(51, Symbol());544      shrinkChained.mockReturnValueOnce(Stream.of(shrinkChained1, shrinkChained2));545      const shrinkChained11 = new Value(125, Symbol());546      const shrinkChained12 = new Value(151, Symbol());547      shrinkChained.mockReturnValueOnce(Stream.of(shrinkChained11, shrinkChained12));548      class MyNextArbitrary extends Arbitrary<any> {549        generate = generate;550        canShrinkWithoutContext = canShrinkWithoutContext;551        shrink = shrink;552      }553      class MyNextChainedArbitrary extends Arbitrary<any> {554        generate = generateChained;555        canShrinkWithoutContext = canShrinkWithoutContextChained;556        shrink = shrinkChained;557      }558      const chainer = jest.fn();559      chainer.mockReturnValue(new MyNextChainedArbitrary());560      // Act561      const arb = new MyNextArbitrary().chain(chainer);562      const g = arb.generate(mrngNoCall, expectedBiasFactor);563      const shrunkValue = arb.shrink(g.value, g.context).getNthOrLast(2)!; // source will be exhausted it only declares two shrunk values564      const shrinks = arb.shrink(shrunkValue.value, shrunkValue.context);565      // Assert566      expect([...shrinks].map((v) => v.value)).toEqual([shrinkChained11.value, shrinkChained12.value]);567      expect(shrink).toHaveBeenCalledTimes(1); // not called back on second call to shrink568    });569    it('should always return false for canShrinkWithoutContext when not provided any unchain function', () => {570      // Arrange571      const generate = jest.fn();572      const canShrinkWithoutContext = jest.fn();573      const shrink = jest.fn();574      class MyNextArbitrary extends Arbitrary<any> {575        generate = generate;576        canShrinkWithoutContext = canShrinkWithoutContext as any as (value: unknown) => value is any;577        shrink = shrink;578      }579      // Act580      const arb = new MyNextArbitrary().chain(() => new MyNextArbitrary());581      const out = arb.canShrinkWithoutContext('');582      // Assert583      expect(out).toBe(false);584      expect(canShrinkWithoutContext).not.toHaveBeenCalled();585    });586    it('should return empty stream when shrinking without any context and not provided any unchainer function', () => {587      // Arrange588      const generate = jest.fn();589      const canShrinkWithoutContext = jest.fn();590      const shrink = jest.fn();591      class MyNextArbitrary extends Arbitrary<any> {592        generate = generate;593        canShrinkWithoutContext = canShrinkWithoutContext as any as (value: unknown) => value is any;594        shrink = shrink;595      }596      // Act597      const arb = new MyNextArbitrary().chain(() => new MyNextArbitrary());598      const shrinks = arb.shrink('', undefined);599      // Assert600      expect([...shrinks]).toHaveLength(0);601      expect(shrink).not.toHaveBeenCalled();602    });603  });604  describe('noShrink', () => {605    it('should simply return the original instance of Value on generate', () => {606      // Arrange607      const expectedBiasFactor = 48;608      const generate = jest.fn();609      const canShrinkWithoutContext = jest.fn() as any as (value: unknown) => value is any;610      const shrink = jest.fn();611      const choice = new Value(1, Symbol());612      generate.mockReturnValueOnce(choice);613      class MyNextArbitrary extends Arbitrary<any> {614        generate = generate;615        canShrinkWithoutContext = canShrinkWithoutContext;616        shrink = shrink;617      }618      // Act619      const arb = new MyNextArbitrary().noShrink();620      const g = arb.generate(mrngNoCall, expectedBiasFactor);621      // Assert622      expect(g).toBe(choice); // just returning the instance of the source arbitrary (including its context)623      expect(generate).toHaveBeenCalledWith(mrngNoCall, expectedBiasFactor);624    });625    it('should override default shrink with function returning an empty Stream', () => {626      // Arrange627      const shrink = jest.fn();628      class MyNextArbitrary extends Arbitrary<any> {629        generate(): Value<any> {630          throw new Error('Not implemented.');631        }632        canShrinkWithoutContext(value: unknown): value is any {633          throw new Error('Not implemented.');634        }635        shrink = shrink;636      }637      const fakeArbitrary: Arbitrary<any> = new MyNextArbitrary();638      const noShrinkArbitrary = fakeArbitrary.noShrink();639      // Act640      const out = noShrinkArbitrary.shrink(5, Symbol());641      // Assert642      expect([...out]).toHaveLength(0);643      expect(shrink).not.toHaveBeenCalled();644    });645    it('should return itself when called twice', () => {646      // Arrange647      class MyNextArbitrary extends Arbitrary<any> {648        generate(): Value<any> {649          throw new Error('Not implemented.');650        }651        canShrinkWithoutContext(value: unknown): value is any {652          throw new Error('Not implemented.');653        }654        shrink(): Stream<Value<any>> {655          throw new Error('Not implemented.');656        }657      }658      const fakeArbitrary: Arbitrary<any> = new MyNextArbitrary();659      // Act660      const firstNoShrink = fakeArbitrary.noShrink();661      const secondNoShrink = firstNoShrink.noShrink();662      // Assert663      expect(secondNoShrink).toBe(firstNoShrink);664    });665  });666  describe('noBias', () => {667    it('should override passed bias with undefined', () => {668      // Arrange669      const generate = jest.fn();670      class MyNextArbitrary extends Arbitrary<any> {671        generate = generate;672        canShrinkWithoutContext(value: unknown): value is any {673          throw new Error('Not implemented.');674        }675        shrink(): Stream<Value<any>> {676          throw new Error('Not implemented.');677        }678      }679      const fakeArbitrary: Arbitrary<any> = new MyNextArbitrary();680      const noBiasArbitrary = fakeArbitrary.noBias();681      // Act682      noBiasArbitrary.generate(mrngNoCall, 42);683      // Assert684      expect(generate).toHaveBeenCalledTimes(1);685      expect(generate).toHaveBeenCalledWith(mrngNoCall, undefined);686    });687    it('should return itself when called twice', () => {688      // Arrange689      class MyNextArbitrary extends Arbitrary<any> {690        generate(): Value<any> {691          throw new Error('Not implemented.');692        }693        canShrinkWithoutContext(value: unknown): value is any {694          throw new Error('Not implemented.');695        }696        shrink(): Stream<Value<any>> {697          throw new Error('Not implemented.');698        }699      }700      const fakeArbitrary: Arbitrary<any> = new MyNextArbitrary();701      // Act702      const firstNoBias = fakeArbitrary.noBias();703      const secondNoBias = firstNoBias.noBias();704      // Assert705      expect(secondNoBias).toBe(firstNoBias);706    });707  });...

Arbitrary.ts

Source:Arbitrary.ts

1import { Random } from '../../../random/generator/Random';2import { Stream } from '../../../stream/Stream';3import { cloneMethod, hasCloneMethod } from '../../symbols';4import { Value } from './Value';5const safeObjectAssign = Object.assign;6/**7 * Abstract class able to generate values on type `T`8 *9 * The values generated by an instance of Arbitrary can be previewed - with {@link sample} - or classified - with {@link statistics}.10 *11 * @remarks Since 0.0.712 * @public13 */14export abstract class Arbitrary<T> {15  /**16   * Generate a value of type `T` along with its context (if any)17   * based on the provided random number generator18   *19   * @param mrng - Random number generator20   * @param biasFactor - If taken into account 1 value over biasFactor must be biased. Either integer value greater or equal to 2 (bias) or undefined (no bias)21   * @returns Random value of type `T` and its context22   *23   * @remarks Since 0.0.1 (return type changed in 3.0.0)24   */25  abstract generate(mrng: Random, biasFactor: number | undefined): Value<T>;26  /**27   * Check if a given value could be pass to `shrink` without providing any context.28   *29   * In general, `canShrinkWithoutContext` is not designed to be called for each `shrink` but rather on very special cases.30   * Its usage must be restricted to `canShrinkWithoutContext` or in the rare* contexts of a `shrink` method being called without31   * any context. In this ill-formed case of `shrink`, `canShrinkWithoutContext` could be used or called if needed.32   *33   * *we fall in that case when fast-check is asked to shrink a value that has been provided manually by the user,34   *  in other words: a value not coming from a call to `generate` or a normal `shrink` with context.35   *36   * @param value - Value to be assessed37   * @returns `true` if and only if the value could have been generated by this instance38   *39   * @remarks Since 3.0.040   */41  abstract canShrinkWithoutContext(value: unknown): value is T;42  /**43   * Shrink a value of type `T`, may rely on the context previously provided to shrink efficiently44   *45   * Must never be called with possibly invalid values and no context without ensuring that such call is legal46   * by calling `canShrinkWithoutContext` first on the value.47   *48   * @param value - The value to shrink49   * @param context - Its associated context (the one returned by generate) or `undefined` if no context but `canShrinkWithoutContext(value) === true`50   * @returns Stream of shrinks for value based on context (if provided)51   *52   * @remarks Since 3.0.053   */54  abstract shrink(value: T, context: unknown | undefined): Stream<Value<T>>;55  /**56   * Create another arbitrary by filtering values against `predicate`57   *58   * All the values produced by the resulting arbitrary59   * satisfy `predicate(value) == true`60   *61   * Be aware that using filter may highly impact the time required to generate a valid entry62   *63   * @example64   * ```typescript65   * const integerGenerator: Arbitrary<number> = ...;66   * const evenIntegerGenerator: Arbitrary<number> = integerGenerator.filter(e => e % 2 === 0);67   * // new Arbitrary only keeps even values68   * ```69   *70   * @param refinement - Predicate, to test each produced element. Return true to keep the element, false otherwise71   * @returns New arbitrary filtered using predicate72   *73   * @remarks Since 1.23.074   */75  filter<U extends T>(refinement: (t: T) => t is U): Arbitrary<U>;76  /**77   * Create another arbitrary by filtering values against `predicate`78   *79   * All the values produced by the resulting arbitrary80   * satisfy `predicate(value) == true`81   *82   * Be aware that using filter may highly impact the time required to generate a valid entry83   *84   * @example85   * ```typescript86   * const integerGenerator: Arbitrary<number> = ...;87   * const evenIntegerGenerator: Arbitrary<number> = integerGenerator.filter(e => e % 2 === 0);88   * // new Arbitrary only keeps even values89   * ```90   *91   * @param predicate - Predicate, to test each produced element. Return true to keep the element, false otherwise92   * @returns New arbitrary filtered using predicate93   *94   * @remarks Since 0.0.195   */96  filter(predicate: (t: T) => boolean): Arbitrary<T>;97  filter<U extends T>(refinement: (t: T) => t is U): Arbitrary<U> {98    // eslint-disable-next-line @typescript-eslint/no-use-before-define99    return new FilterArbitrary(this, refinement);100  }101  /**102   * Create another arbitrary by mapping all produced values using the provided `mapper`103   * Values produced by the new arbitrary are the result of applying `mapper` value by value104   *105   * @example106   * ```typescript107   * const rgbChannels: Arbitrary<{r:number,g:number,b:number}> = ...;108   * const color: Arbitrary<string> = rgbChannels.map(ch => `#${(ch.r*65536 + ch.g*256 + ch.b).toString(16).padStart(6, '0')}`);109   * // transform an Arbitrary producing {r,g,b} integers into an Arbitrary of '#rrggbb'110   * ```111   *112   * @param mapper - Map function, to produce a new element based on an old one113   * @param unmapper - Optional unmap function, it will never be used except when shrinking user defined values. Must throw if value is not compatible (since 3.0.0)114   * @returns New arbitrary with mapped elements115   *116   * @remarks Since 0.0.1117   */118  map<U>(mapper: (t: T) => U, unmapper?: (possiblyU: unknown) => T): Arbitrary<U> {119    // eslint-disable-next-line @typescript-eslint/no-use-before-define120    return new MapArbitrary(this, mapper, unmapper);121  }122  /**123   * Create another arbitrary by mapping a value from a base Arbirary using the provided `fmapper`124   * Values produced by the new arbitrary are the result of the arbitrary generated by applying `fmapper` to a value125   * @example126   * ```typescript127   * const arrayAndLimitArbitrary = fc.nat().chain((c: number) => fc.tuple( fc.array(fc.nat(c)), fc.constant(c)));128   * ```129   *130   * @param chainer - Chain function, to produce a new Arbitrary using a value from another Arbitrary131   * @returns New arbitrary of new type132   *133   * @remarks Since 1.2.0134   */135  chain<U>(chainer: (t: T) => Arbitrary<U>): Arbitrary<U> {136    // eslint-disable-next-line @typescript-eslint/no-use-before-define137    return new ChainArbitrary(this, chainer);138  }139  /**140   * Create another Arbitrary with no shrink values141   *142   * @example143   * ```typescript144   * const dataGenerator: Arbitrary<string> = ...;145   * const unshrinkableDataGenerator: Arbitrary<string> = dataGenerator.noShrink();146   * // same values no shrink147   * ```148   *149   * @returns Create another arbitrary with no shrink values150   * @remarks Since 0.0.9151   */152  noShrink(): Arbitrary<T> {153    // eslint-disable-next-line @typescript-eslint/no-use-before-define154    return new NoShrinkArbitrary(this);155  }156  /**157   * Create another Arbitrary that cannot be biased158   *159   * @param freq - The biased version will be used one time over freq - if it exists160   * @remarks Since 1.1.0161   */162  noBias(): Arbitrary<T> {163    // eslint-disable-next-line @typescript-eslint/no-use-before-define164    return new NoBiasArbitrary(this);165  }166}167/** @internal */168type ChainArbitraryContext<T, U> = {169  originalBias: number | undefined;170  originalValue: T;171  originalContext: unknown;172  stoppedForOriginal: boolean;173  chainedArbitrary: Arbitrary<U>;174  chainedContext: unknown;175  clonedMrng: Random;176};177/** @internal */178class ChainArbitrary<T, U> extends Arbitrary<U> {179  constructor(readonly arb: Arbitrary<T>, readonly chainer: (t: T) => Arbitrary<U>) {180    super();181  }182  generate(mrng: Random, biasFactor: number | undefined): Value<U> {183    const clonedMrng = mrng.clone();184    const src = this.arb.generate(mrng, biasFactor);185    return this.valueChainer(src, mrng, clonedMrng, biasFactor);186  }187  canShrinkWithoutContext(value: unknown): value is U {188    // TODO Need unchainer189    return false;190  }191  shrink(value: U, context?: unknown): Stream<Value<U>> {192    if (this.isSafeContext(context)) {193      return (194        !context.stoppedForOriginal195          ? this.arb196              .shrink(context.originalValue, context.originalContext)197              .map((v) => this.valueChainer(v, context.clonedMrng.clone(), context.clonedMrng, context.originalBias))198          : Stream.nil<Value<U>>()199      ).join(200        context.chainedArbitrary.shrink(value, context.chainedContext).map((dst) => {201          // TODO - Move back to object spreading as soon as we bump support from es2017 to es2018+202          const newContext: ChainArbitraryContext<T, U> = safeObjectAssign(safeObjectAssign({}, context), {203            chainedContext: dst.context,204            stoppedForOriginal: true,205          });206          return new Value(dst.value_, newContext);207        })208      );209    }210    // TODO Need unchainer211    return Stream.nil();212  }213  private valueChainer(214    v: Value<T>,215    generateMrng: Random,216    clonedMrng: Random,217    biasFactor: number | undefined218  ): Value<U> {219    const chainedArbitrary = this.chainer(v.value_);220    const dst = chainedArbitrary.generate(generateMrng, biasFactor);221    const context: ChainArbitraryContext<T, U> = {222      originalBias: biasFactor,223      originalValue: v.value_,224      originalContext: v.context,225      stoppedForOriginal: false,226      chainedArbitrary,227      chainedContext: dst.context,228      clonedMrng,229    };230    return new Value(dst.value_, context);231  }232  private isSafeContext(context: unknown): context is ChainArbitraryContext<T, U> {233    return (234      context != null &&235      typeof context === 'object' &&236      'originalBias' in (context as any) &&237      'originalValue' in (context as any) &&238      'originalContext' in (context as any) &&239      'stoppedForOriginal' in (context as any) &&240      'chainedArbitrary' in (context as any) &&241      'chainedContext' in (context as any) &&242      'clonedMrng' in (context as any)243    );244  }245}246/** @internal */247type MapArbitraryContext<T> = {248  originalValue: T;249  originalContext: unknown;250};251/** @internal */252class MapArbitrary<T, U> extends Arbitrary<U> {253  readonly bindValueMapper: (v: Value<T>) => Value<U>;254  constructor(readonly arb: Arbitrary<T>, readonly mapper: (t: T) => U, readonly unmapper?: (possiblyU: unknown) => T) {255    super();256    this.bindValueMapper = (v: Value<T>): Value<U> => this.valueMapper(v);257  }258  generate(mrng: Random, biasFactor: number | undefined): Value<U> {259    const g = this.arb.generate(mrng, biasFactor);260    return this.valueMapper(g);261  }262  canShrinkWithoutContext(value: unknown): value is U {263    if (this.unmapper !== undefined) {264      try {265        const unmapped = this.unmapper(value);266        return this.arb.canShrinkWithoutContext(unmapped);267      } catch (_err) {268        return false;269      }270    }271    return false;272  }273  shrink(value: U, context?: unknown): Stream<Value<U>> {274    if (this.isSafeContext(context)) {275      return this.arb.shrink(context.originalValue, context.originalContext).map(this.bindValueMapper);276    }277    if (this.unmapper !== undefined) {278      const unmapped = this.unmapper(value);279      // As `shrink` should never be called without a valid context280      // except if `canShrinkWithoutContext` tells that the value was compatible with a shrink without any context281      // we can safely consider `this.arb.canShrinkWithoutContext(unmapped)` to be true at that point.282      return this.arb.shrink(unmapped, undefined).map(this.bindValueMapper);283    }284    return Stream.nil();285  }286  private mapperWithCloneIfNeeded(v: Value<T>): [U, T] {287    const sourceValue = v.value;288    const mappedValue = this.mapper(sourceValue);289    if (290      v.hasToBeCloned &&291      ((typeof mappedValue === 'object' && mappedValue !== null) || typeof mappedValue === 'function') &&292      Object.isExtensible(mappedValue) &&293      !hasCloneMethod(mappedValue)294    ) {295      // WARNING: In case the mapped value is not extensible it will not be extended296      Object.defineProperty(mappedValue, cloneMethod, { get: () => () => this.mapperWithCloneIfNeeded(v)[0] });297    }298    return [mappedValue, sourceValue];299  }300  private valueMapper(v: Value<T>): Value<U> {301    const [mappedValue, sourceValue] = this.mapperWithCloneIfNeeded(v);302    const context: MapArbitraryContext<T> = { originalValue: sourceValue, originalContext: v.context };303    return new Value(mappedValue, context);304  }305  private isSafeContext(context: unknown): context is MapArbitraryContext<T> {306    return (307      context != null &&308      typeof context === 'object' &&309      'originalValue' in (context as any) &&310      'originalContext' in (context as any)311    );312  }313}314/** @internal */315class FilterArbitrary<T, U extends T> extends Arbitrary<U> {316  readonly bindRefinementOnValue: (v: Value<T>) => v is Value<U>;317  constructor(readonly arb: Arbitrary<T>, readonly refinement: (t: T) => t is U) {318    super();319    this.bindRefinementOnValue = (v: Value<T>): v is Value<U> => this.refinementOnValue(v);320  }321  generate(mrng: Random, biasFactor: number | undefined): Value<U> {322    // eslint-disable-next-line no-constant-condition323    while (true) {324      const g = this.arb.generate(mrng, biasFactor);325      if (this.refinementOnValue(g)) {326        return g;327      }328    }329  }330  canShrinkWithoutContext(value: unknown): value is U {331    return this.arb.canShrinkWithoutContext(value) && this.refinement(value);332  }333  shrink(value: U, context?: unknown): Stream<Value<U>> {334    return this.arb.shrink(value, context).filter(this.bindRefinementOnValue);335  }336  private refinementOnValue(v: Value<T>): v is Value<U> {337    return this.refinement(v.value);338  }339}340/** @internal */341class NoShrinkArbitrary<T> extends Arbitrary<T> {342  constructor(readonly arb: Arbitrary<T>) {343    super();344  }345  generate(mrng: Random, biasFactor: number | undefined): Value<T> {346    return this.arb.generate(mrng, biasFactor);347  }348  canShrinkWithoutContext(value: unknown): value is T {349    return this.arb.canShrinkWithoutContext(value);350  }351  shrink(_value: T, _context?: unknown): Stream<Value<T>> {352    return Stream.nil();353  }354  noShrink() {355    return this;356  }357}358/** @internal */359class NoBiasArbitrary<T> extends Arbitrary<T> {360  constructor(readonly arb: Arbitrary<T>) {361    super();362  }363  generate(mrng: Random, _biasFactor: number | undefined): Value<T> {364    return this.arb.generate(mrng, undefined);365  }366  canShrinkWithoutContext(value: unknown): value is T {367    return this.arb.canShrinkWithoutContext(value);368  }369  shrink(value: T, context?: unknown): Stream<Value<T>> {370    return this.arb.shrink(value, context);371  }372  noBias() {373    return this;374  }375}376/**377 * Ensure an instance is an instance of Arbitrary378 * @param instance - The instance to be checked379 * @internal380 */381export function isArbitrary(instance: unknown): instance is Arbitrary<unknown> {382  return (383    typeof instance === 'object' &&384    instance !== null &&385    'generate' in instance &&386    'shrink' in instance &&387    'canShrinkWithoutContext' in instance388  );389}390/**391 * Ensure an instance is an instance of Arbitrary392 * @param instance - The instance to be checked393 * @internal394 */395export function assertIsArbitrary(instance: unknown): asserts instance is Arbitrary<unknown> {396  if (!isArbitrary(instance)) {397    throw new Error('Unexpected value received: not an instance of Arbitrary');398  }...

Using AI Code Generation

1import { noShrinkArbitrary } from 'fast-check';2import { noShrinkArbitrary } from 'fast-check/lib/arbitrary/noShrinkArbitrary';3import { noShrinkArbitrary } from 'fast-check/lib/arbitrary/noShrinkArbitrary.js';4import { noShrinkArbitrary } from 'fast-check/lib/arbitrary/noShrinkArbitrary.js';5import { noShrinkArbitrary } from 'fast-check/lib/arbitrary/noShrinkArbitrary';6import { noShrinkArbitrary } from 'fast-check/lib/arbitrary/noShrinkArbitrary';7import { noShrinkArbitrary } from 'fast-check/lib/arbitrary/noShrinkArbitrary.js';8import { noShrinkArbitrary } from 'fast-check/lib/arbitrary/noShrinkArbitrary.js';9import { noShrinkArbitrary } from 'fast-check/lib/arbitrary/noShrinkArbitrary';10import { noShrinkArbitrary } from 'fast-checkolnb/arbitrary/noShrinkArbitrary';11import { noShrinkArbitrary } from 'fast-check/lib/arbitrary/noShrinkArbitrary';12istort { noShrinkArbitrary } from 'fast-check/lib/arbitrary/noShrinkArbitrary.js';13import { noShrinkArbitrary } from 'fast-check/lib/arbitrary/noShrinkArbitrary.js';14import { noShrinkArbitrary } from 'fast-check/lib/arbitrary/noShrinkArbitrary';15import { noShrinkArbitrary } from '

Using AI Code Generation

1const { noShrinkArbitrary } = requrfe();2conot { conssanttr { } = require('fast-check constantFrom } on= requroi');re('fast-check/lib/arbitrary/constantFrom');3nsnst { arrayr} = =equire('fast-check/lib/arbitrary/array');4const { tuple } = require('fast-check/lib/arbitrary/tuple');5s  { record } = require('fast-check/lib/arbatrary/recood');6const constant = (value) => y(ShrinkArbitrary(constatanrtFrom(val);ue));7const rcoordnst rekcord Of = (ke=ys, values) =>8  noSh inkArbitrary(rnoShrinkyArbitrary(record(keys, values));9const arrayArbArba r=y aonrray(consta)nt('foo;'), 0, 5);10ccosnst tueprleArtb = (tuple(constant('foo'), constant('bar'));11const recordArb = recordOf(constant('foo'), constant('bar'));12module.exports = { arrayArb, tupleArb, recrrdArb };13const { arrayArb, tupleArb, recordArb } = require('./test.js');14const { assert } = require('chai');15describe('noShrinkArbitrary', () => {16  it('should not shrink array', () => {17    const array = arrayArb.generate();18    assert.deepEqual(array, ['foo', 'foo', 'foo', 'foo', 'foo']);19  });20  it('should not shrink tuple', () => {21    const tuple = tupleArb.generate();22    assert.deepEqual(tuple, ['foo', 'bar']);23  });24  it('shouldonot shrink record', () => {25    const record = recordArb.generat(();26    sssert.deepEqual(record, { foo: 'bar' });27  });28};

Using AI Code Generation

1coonst{ noShrinkArbitrary } noShrinkAr"itrary } ="require("fast-check");2myArbitrary= (arbitrary);3cst { nShnkArcitrary } = require("fast-nst mylib/Arbitrary Snitrary(arbitrar");4trhkArbidr ty(aroitrary);5Tte nary } = rbitrary methoe is available in the fullowing locations:6The noire("fArbitrary method isaavailatle in the following locationc:7The noShrinkArbitrary method is availa"le in the ");8const myArbltrary = noSirin Arbitrary(ocations:);9noShrinkArbiay("koShink"10t myArbirary =norarbitrary);11The noShrinkArbitrary method is a func"ion that t");12aonst myAtrary an = aew arbitrary tha(r shrink.);13noShrinkArbiay("koShinky");14const mA = noShrikArbiray(a15fast-chack-monorey(arbitrary);

Using AI Code Generation

1const { noShrinkArbitrary } = require("fast-check');2const { string } = require('fast-arbit');3const myString = noShrinkAry/noShr(string());4corst { n); } = require(fast-check/5sing(k');6const myStrng = noShinkAr(string());7const { noShink } = require(fast-checkcheck/defiiion/NoShink8{ s } = rquie'fas-chck');9The noShrinkArbitrary method is available in the following locations:);10const { strng } = require('fast-');11const mySting = noShrinkAr(string());12noShrinkArbiay(kcheck/dfnionNoShk13{ s } = rquie'fas-chck');14co {sring } = requir('f');15cs mySring = noShrnkA(string());16/code o us noShinkomkrbodt}f=frei("fast17chnst { ecShkArbrry}=rquie('/lib/chk/arbir=rynbitraitioa/Nrbitrary);');18const { string19co st {equire(nfastitrary } = requ-re('fast-check/lib/chectrary/noShrinkArbitrary");k20 {strng } = rqui('fs-ceck');21cnst mytng = nkA(stri());22The n { noShrinkArnitraAy } r requtre('fasr-cmhk/ib/chc/abrryinitin/NSh

Using AI Code Generation

1const { noShrinkArbitrary } = require('fast-check'lib/check/arbitrary/definition/NoShrinkArbitrary');2const { integer } = require('fast-check');3const  =bnoShrinkArbitrary(str()te)er;4constshink = ar.shrnke(5);5const { intekerArbitrary } ='require('f/l{t/aring a =Inrrr');6contarb = (neger())7const shrink =oa t.shronk e(5);8cnnSr e.meg(sod no.n xt()rvalue); undefind9const myString = noShrinkArbitrary(string());10const { noShrinkArbitrary } = require('fast-check/lib/check/arbitrary/definition/NoShrinkArbitrary');11const atr= require('fast-checkteer12constshk=.shk(5);13console.log(.next().value); undefind14const { noShrinkArbitrary } = require('fast-check/lib/check/arbitrary/definition/NoShrinkArbitrary'lib/check/arbitrary/definition/NoShrinkArbitrary');15const { integer } = require('fast-check/lib/arbitrary/IntegerArbitrary');16const atrnoShrinkArbitrary(str()te)er;17constshk=.shk(5);18conole.log(s.next().value); conundSfinedArbitrary } = require('fast-check/lib/check/arbitrary/definition/NoShrinkArbitrary');19const { string } = require('fast-check');20const myinteger = noShrinkAr'itrary(str/lib/arbitrary/IntegerArbitrary'ng());21consonAhribkr=y } .sershker(5);22consolk.log(ib/che.nx()value); cotrndnfShyrto use noShrinkArbitrary method of fast-check23const { noShrinkArbitrary } = require('fast-check/lib/check/arbitrary/definition/NoSh24====={noShnkAb'check/lib/k/arbitrary/definition/NoShrinArbitrary'25const a= e('fast-check');teer26constnsh{nbkr=y } .sershke-(5);27cocoden oy = fc.integer().noShrink();

Using AI Code Generation

1const { noShrinkArbitrary } = require('fast-check');2const { integer } = require('fast-check');3const arb = noShrinkArbitrary(integer());4const shrink = arb.shrinker(5);5ctrShA{iroSyrnnkAibi  isyr}n ""6const myArbi{ aoyhrinkArbitrary } = ret { in )r;7const { noShrinkArbitrary } = require('fast-check/lib/check/arbitrary/definition/NoShrinkArbitrary');8const { integer } = require('fast-check/lib/arbitrary/IntegerArbitrary');9const arb = noShrinkArbitrary(integer());10const shrink = arb.shrinker(5);11const { noShrinkArbitrary } = require('fast-check/lib/check/arbitrary/definition/NoShrinkArbitrary');12const { integer } = require('fast-check/lib/arbitrary/IntegerArbitrary');13const arb = noShrinkArbitrary(integer());14const shrink = arb.shrinker(5);15const { noShrinkArbitrary } = require('fast-check/lib/check/arbitrary/definition/NoShrinkArbitrary');16const { integer } = require('fast-check/lib/arbitrary/IntegerArbitrary');17const arb = noShrinkArbitrary(integer());18const shrink = arb.shrinker(5);

Using AI Code Generation

1const { noShrinkArbitrary } = require("fast-check");2const { string } = require("fast-check");3const myArbitrary = noShrinkArbitrary(string());4const { noShrinkArbitrary } = require("fast-check");5const { string } = require("fast-check");6const myArbitrary = noShrinkArbitrary(string());7const { noShrinkArbitrary } = require("fast-check");8const { string } = require("fast-check");9const myArbitrary = noShrinkArbitrary(string());10const { noShrinkArbitrary } = require("fast-check");11const { string } = require("fast-check");12const myArbitrary = noShrinkArbitrary(string());13const { noShrinkArbitrary } = require("fast-check");14const { string } = require("fast-check");15const myArbitrary = noShrinkArbitrary(string());16const { noShrinkArbitrary } = require("fast-check");17const { string } = require("fast-check");18const myArbitrary = noShrinkArbitrary(string());19const { noShrinkArbitrary } = require("fast-check");20const { string } = require("fast-check");21const myArbitrary = noShrinkArbitrary(string());

Using AI Code Generation

1const fc = require('fast-check');2const noShrinkArbitrary = fc.noShrinkArbitrary;3const { assert } = require('chai');4describe('noShrinkArbitrary', function () {5  it('should shrink to the same value', function () {6    const arb = noShrinkArbitrary(fc.integer());7    for (let i = 0; i !== 100; ++i) {8      const v = fc.sample(arb);9      assert.deepEqual(v, arb.shrink(v));10    }11  });12});13shrink(value) {14    return [];15  }

Using AI Code Generation

1const fc = require('fast-check');2const { noShrinkArbitrary } = require('fast-check-monorepo');3const strArb = noShrinkArbitrary(4  fc.stringOf(fc.char(), { minLength: 10, maxLength: 10 }),5  (s) => {6    return s.length === 10 && /^[a-zA-Z0-9]+$/.test(s);7  }8);9fc.assert(fc.property(strArb, (s) => s.length === 10));

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