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How to use fakeRandom method in fast-check-monorepo

Best JavaScript code snippet using fast-check-monorepo

createErrorRecord.spec.js

1import errorRecord from '../createErrorRecord';2jest.spyOn(console, 'error');3const fakeSeconds = jest.fn();4const fakeRandom = jest.fn();5const fakeWindow = {6    location: window.location,7    Date: class {8        getSeconds() {9            return fakeSeconds();10        }11    },12    Math: {13        random: fakeRandom14    }15};16beforeEach(() => {17    console.error.mockClear();18    fakeSeconds.mockClear();19    fakeRandom.mockClear();20});21afterAll(() => {22    console.error.mockRestore();23});24const firstError = new Error('test');25test('creates a record from an error', () => {26    fakeSeconds.mockReturnValueOnce(30);27    fakeRandom.mockReturnValueOnce(0.456);28    const record = errorRecord(firstError, fakeWindow);29    expect(record).toMatchObject({30        error: firstError,31        id: 'Error30G',32        loc: expect.stringMatching(/^at /)33    });34});35test('caches already seen errors', () => {36    const record = errorRecord(firstError, fakeWindow);37    expect(record).toMatchObject({38        error: firstError,39        id: 'Error30G',40        loc: expect.stringMatching(/^at /)41    });42    expect(fakeSeconds).not.toHaveBeenCalled();43});44test('makes IDs from error names or constructor names', () => {45    fakeSeconds.mockReturnValue(1);46    fakeRandom.mockReturnValue(0.1);47    class CustomError extends Error {}48    expect(errorRecord(new CustomError('bluh'), fakeWindow)).toMatchObject({49        id: 'CustomError13'50    });51    Object.defineProperty(CustomError, 'name', {52        value: 'CustomNameOverride'53    });54    expect(errorRecord(new CustomError('blar'), fakeWindow)).toMatchObject({55        id: 'CustomNameOverride13'56    });57    Object.defineProperty(CustomError, 'name', {58        value: undefined59    });60    const errorWithName = new CustomError('ack');61    Object.defineProperty(errorWithName, 'name', {62        value: 'ACK'63    });64    expect(errorRecord(errorWithName, fakeWindow)).toMatchObject({65        id: 'ACK13'66    });67    const errorWithNoConstructor = new Error('ack');68    Object.defineProperties(errorWithNoConstructor, {69        constructor: {70            value: undefined71        },72        name: {73            value: 'woah'74        }75    });76    expect(errorRecord(errorWithNoConstructor, fakeWindow)).toMatchObject({77        id: 'woah13'78    });79});80test('uses custom stacks', () => {81    fakeSeconds.mockReturnValue(1);82    fakeRandom.mockReturnValue(0.1);83    expect(84        errorRecord(85            new Error('guh'),86            fakeWindow,87            {},88            'Error: guh\n at a custom stack'89        )90    ).toMatchObject({91        loc: 'at a custom stack'92    });93});94test('loc is empty if stack cannot be parsed', () => {95    fakeSeconds.mockReturnValue(1);96    fakeRandom.mockReturnValue(0.1);97    expect(98        errorRecord(new Error('guh'), fakeWindow, {}, 'an unrecognizable stack')99    ).toMatchObject({100        loc: ''101    });...

simpleVirus.test.ts

Source: simpleVirus.test.ts

1import { createSimpleVirus, createSimpleVirusPopulation } from './simpleVirus';2describe('createSimpleVirus', () => {3  it('returns the birthProb and clearProb args as properties', () => {4    const { birthProb, clearProb } = createSimpleVirus({5      birthProb: 0.3,6      clearProb: 0.5,7      random0to1: Math.random,8    });9    expect(birthProb).toEqual(0.3);10    expect(clearProb).toEqual(0.5);11  });12  it('returns a method doesSurvive that returns true when random is bigger than clearProb', () => {13    const fakeRandom = () => 0.4;14    const virus = createSimpleVirus({15      birthProb: 0.3,16      clearProb: 0.3,17      random0to1: fakeRandom,18    });19    expect(virus.doesSurvive()).toEqual(true);20  });21  it('returns a method doesSurvive that returns false when random is smaller than clearProb', () => {22    const fakeRandom = () => 0.2;23    const virus = createSimpleVirus({24      birthProb: 0.3,25      clearProb: 0.3,26      random0to1: fakeRandom,27    });28    expect(virus.doesSurvive()).toEqual(false);29  });30  it('returns a method doesReproduce that returns true when random is smaller than birthProb * (1 - popDensity)', () => {31    const fakeRandom = () => 0.4;32    const virus = createSimpleVirus({33      birthProb: 1,34      clearProb: 0.3,35      random0to1: fakeRandom,36    });37    // random 0.4 < birthProb 1 * (1 - 0.5) // true38    expect(virus.doesReproduce(0.5)).toEqual(true);39  });40  it('returns a method doesReproduce that returns false when random is larger than birthProb * (1 - popDensity)', () => {41    const fakeRandom = () => 0.6;42    const virus = createSimpleVirus({43      birthProb: 1,44      clearProb: 0.3,45      random0to1: fakeRandom,46    });47    // random 0.6 < birthProb 1 * (1 - 0.5) // false48    expect(virus.doesReproduce(0.5)).toEqual(false);49  });50});51describe('createVirusPopulation', () => {52  it('returns an array of the specified length', () => {53    const viruses = createSimpleVirusPopulation({54      virusCount: 13,55      birthProb: 0.1,56      clearProb: 0.01,57    });58    expect(viruses.length).toEqual(13);59  });...

jest.setup.after.js

Source: jest.setup.after.js

1let fakeRandom = 0;2beforeEach(() => {3  jest.spyOn(global.Math, 'random').mockImplementation(() => {4    fakeRandom += 0.00001;5    return fakeRandom;6  });7});8afterEach(() => {9  fakeRandom = 0;10  jest.spyOn(global.Math, 'random').mockRestore();...

Using AI Code Generation

1import * as fc from "fast-check";2import { fakeRandom } from "fast-check-monorepo";3describe("test3", () => {4    it("test3", () => {5        fc.assert(6            fc.property(fc.integer(), fc.integer(), (a, b) => {7                const random = fakeRandom([a, b]);8                return random() === a && random() === b;9            })10        );11    });12});13import * as fc from "fast-check";14import { fakeRandom } from "fast-check-monorepo";15describe("test3", () => {16    it("test3", () => {17        fc.assert(18            fc.property(fc.integer(), fc.integer(), (a, b) => {19                const random = fakeRandom([a, b]);20                return random() === a;21            })22        );23    });24});25I have a simple test that uses fakeRandom to test a function that uses Math.random() to generate random numbers. The test passes when I use the following code:26import * as fc from "fast-check";27import { fakeRandom } from "fast-check-monorepo";28describe("test1", () => {29    it("test1", () => {30        fc.assert(31            fc.property(fc.integer(), fc.integer(), (a, b) => {32                const random = fakeRandom([a, b]);33                return random() === a;34            })35        );36    });37});38import * as fc from "fast-check";39import { fakeRandom } from "fast-check-monorepo";40describe("test2", () => {41    it("test2", () => {42        fc.assert(43            fc.property(fc.integer(), fc.integer(), (a, b) => {44                const random = fakeRandom([a, b]);45                return random() === a && random() === b;46            })47        );48    });49});

Using AI Code Generation

1const { fakeRandom } = require('fast-check-monorepo');2const { integer } = require('fast-check-monorepo/lib/arbitrary/IntegerArbitrary.js');3const { property } = require('fast-check-monorepo/lib/check/property/Property.js');4property(5  integer(),6  integer(),7  (a, b) => {8    const random = fakeRandom([a, b]);9    return random.nextInt(0, 1) === a;10  }11).check();12    at Object.nextInt (C:\Users\mike\Documents\test3\node_modules\fast-check-monorepo\lib\random\Random.js:32:31)13    at Property.<anonymous> (C:\Users\mike\Documents\test3\test3.js:10:26)14    at Property._execute (C:\Users\mike\Documents\test3\node_modules\fast-check-monorepo\lib\check\property\Property.js:113:19)15    at Property.check (C:\Users\mike\Documents\test3\node_modules\fast-check-monorepo\lib\check\property\Property.js:69:19)16    at Object.<anonymous> (C:\Users\mike\Documents\test3\test3.js:13:9)17    at Module._compile (internal/modules/cjs/loader.js:1137:30)18    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1157:10)19    at Module.load (internal/modules/cjs/loader.js:985:32)20    at Function.Module._load (internal/modules/cjs/loader.js:878:14)21    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:71:12)22So in your case you should install fast-check instead of fast-check-monorepo and import the different packages from

Using AI Code Generation

1const fc = require("fast-check");2const { fakeRandom } = require("fast-check-monorepo");3let random = fakeRandom([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], 0);4fc.assert(5  fc.property(fc.integer(), (n) => {6    return n === random.nextInt(0, 10);7  })8);9const fc = require("fast-check");10const { fakeRandom } = require("fast-check-monorepo");11let random = fakeRandom([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], 0);12fc.assert(13  fc.property(fc.integer(), (n) => {14    return n === random.nextInt(0, 10);15  })16);

Using AI Code Generation

1const fc = require('fast-check');2const { fakeRandom } = require('fast-check-monorepo');3const { fakeRandom } = require('fast-check');4const fc = require('fast-check');5fc.assert(6  fc.property(fc.integer(), fc.integer(), (a, b) => {7    const r = fakeRandom();8    const r = fakeRandom();9    return a + b === b + a;10  })11);

Using AI Code Generation

1import { fakeRandom } from "fast-check-monorepo";2describe("test3", () => {3  it("should work", () => {4    const rand = fakeRandom();5    const result = rand.nextInt(1, 10);6    expect(result).toBe(2);7  });8});9I have a function that takes a string as an argument and returns an array of strings. I want to write a test that checks that the function returns an array of strings. I have tried using expect.any(Array) and expect.arrayContaining() but I am getting the following error when running the test:10I have tried using expect.any(Array) and expect.arrayContaining() but I am getting the following error when running the test:11I am trying to write a test for a function that takes a string as an argument and returns an array of strings. I want to write a test that checks that the function returns an array of strings. I have tried using expect.any(Array) and expect.arrayContaining() but I am getting the following error when running the test:12I am trying to write a test for a function that takes a string as an argument and returns an array of strings. I want to write a test that checks that the function returns an array of strings. I have tried using expect.any(Array) and expect.arrayContaining() but I am getting the following error when running the test:

Using AI Code Generation

1const { fakeRandom } = require('fast-check');2const generateRandomNumber = (min, max) => {3  const random = fakeRandom();4  return random.nextInt(min, max);5};6module.exports = {7};8const { fakeRandom } = require('fast-check');9const generateRandomNumber = (min, max) => {10  const random = fakeRandom();11  return random.nextInt(min, max);12};13module.exports = {14};15const { fakeRandom } = require('fast-check');16const generateRandomNumber = (min, max) => {17  const random = fakeRandom();18  return random.nextInt(min, max);19};20module.exports = {21};22const { fakeRandom } = require('fast-check');23const generateRandomNumber = (min, max) => {24  const random = fakeRandom();25  return random.nextInt(min, max);26};27module.exports = {28};29const { fakeRandom } = require('fast-check');30const generateRandomNumber = (min, max) => {31  const random = fakeRandom();32  return random.nextInt(min, max);33};34module.exports = {35};36const { fakeRandom } = require('fast-check');37const generateRandomNumber = (min, max) => {38  const random = fakeRandom();39  return random.nextInt(min, max);40};41module.exports = {42};

Using AI Code Generation

1const fc = require('fast-check-monorepo');2const { fakeRandom } = fc;3const { myMethod } = require('my-module');4describe('myMethod', () => {5  it('should always return 42', () => {6    fc.assert(7      fc.property(fc.integer(), seed => {8        const rng = fakeRandom(seed);9        const result = myMethod(rng);10        return result === 42;11      })12    );13  });14});15const fc = require('fast-check-monorepo');16const { fakeRandom } = fc;17const { myMethod } = require('my-module');18describe('myMethod', () => {19  it('should always return 42', () => {20    fc.assert(21      fc.property(fc.integer(), fc.integer(), (seed, input) => {22        const rng = fakeRandom(seed);23        const result = myMethod(rng, input);24        return result === 42;25      })26    );27  });28});

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