jest.clearAllMocks is not clearing my test spy's

[njmaeff]

Issue description or question

As I continue writing my tests, the mock counts increase to a very high number. When I run the test using the jest cli, the spy seems to reset because the tests pass.

Here is a sample repository
https://github.com/NikkiJ19/wallaby-jest
branch - issue/mock-clearAll

Okay initially.

Once I begin typing, the counts start racking up.

Jest cli does not show an error.

Wallaby.js configuration file

module.exports = function () {

    return {
        files: [
            'tsconfig.json',
            'package.json',
            '**/__mocks__/**',
            '!/__tests__/**/*.ts',
        ],


        tests: [
            '/__tests__/**/*.ts',
        ],

        filesWithNoCoverageCalculated: [
            '**/__mocks__/**'
        ],

        env: {
            type: 'node',
            runner: 'node'
        },

        testFramework: 'jest',

        debug: true,

        preprocessors: {
            '**/*.js?(x)': file => require('babel-core').transform(
                file.content,
                {sourceMap: true, filename: file.path, presets: ['babel-preset-jest']})
        },
        setup(wallaby) {
            const config = require("./package.json").jest;
            wallaby.testFramework.configure(config);
        }
    };
};

Code editor or IDE name and version

WebStorm 2018.3.4
Build #WS-183.5429.34, built on January 30, 2019
Subscription is active until April 27, 2019
JRE: 1.8.0_152-release-1343-b26 amd64
JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o
Windows 10 10.0

OS name and version

OS Name Microsoft Windows 10 Pro
Version 10.0.17134 Build 17134

[ArtemGovorov]

The issue is not Wallaby specific. The same issue can be reproduced if you run Jest CLI with --watch flag (and comment/uncomment jest.clearAllMocks call):

Note that this issue, and #1991 are specific to fs.existsSync mocking. Other objects/modules mocking should work fine in Jest.

My understanding is that mocking fs.existsSync breaks Jest in unexpected ways (even after you clean the mock out).

Another example of things being wrong is visible on your screenshot - Jest CLI finds an obsolete snapshot, even though it doesn't exist. If you run jest -u, you will get an error saying that the snapshot file doesn't exist, but mocking fs.existsSync makes Jest think that it does.

Another example of broken things is the other issue that you have created - #1991.

I would recommend against mocking fs.existsSync, but if you absolutely have to, you may use Wallaby with workers.recycle = true setting, that will make it work as you would run Jest CLI not in watch mode (like on your screenshot):

module.exports = function () {

    return {
        files: [
            'tsconfig.json',
            'package.json',
            '**/__mocks__/**',
            '!/__tests__/**/*.ts',
        ],


        tests: [
            '/__tests__/**/*.ts',
        ],

        filesWithNoCoverageCalculated: [
            '**/__mocks__/**'
        ],

        env: {
            type: 'node',
            runner: 'node'
        },

        testFramework: 'jest',

        debug: true,

+       workers: {recycle: true},

        preprocessors: {
            '**/*.js?(x)': file => require('babel-core').transform(
                file.content,
                {sourceMap: true, filename: file.path, presets: ['babel-preset-jest']})
        },
        setup(wallaby) {
            const config = require("./package.json").jest;
            wallaby.testFramework.configure(config);
        }
    };
};

The same solution applies to another issue #1991. The solution does come with performance cost (as Jest needs to be restarted).