Convert karma to jest script

convert-to-jest.js

// Can be run with a file like this: 
// node convert-to-jest.js src/app/home/search/search.component.spec.ts   

var fs = require('fs');
var filename = process.argv[2];

if (!filename) {
  let specs = require('glob').sync('src/**/*.spec.ts');
  for (spec of specs) {
    if (!spec.includes('pact')) {
      convertToJest(spec);
    }
  }
} else {
  convertToJest(filename);
}

function convertToJest(filename) {
  if (!filename.startsWith('C:')) {
    filename = './' + filename;
  }

  fs.readFile(filename, 'utf8', function(err, data) {
    if (err) {
      return console.log(err);
    }
    var result = data;
    result = result.replace(/SpyObj</g, 'SpyObject<');
    result = result.replace(/\.and\.returnValue/g, '.mockReturnValue');
    result = result.replace(/\.spec\'/g, '.test');
    result = result.replace(/jasmine\.SpyObj/g, 'SpyObj');
    result = result.replace(/spyOn/g, 'jest.spyOn');
    result = result.replace(/spyOnProperty/g, 'spyOn');
    result = result.replace(
      /expect\((.*)\.calls\.first\(\)\.args\)\.toEqual\(\[(.*)\]\);/g,
      'expect($1).toHaveBeenCalledWith($2);'
    );
    result = result.replace(
      /expect\((.*)\.calls\.any\(\)\)\.toBe\((.*)\);/g,
      'expect($1).toHaveBeenCalledWith($2);'
    );
    result = result.replace(
      /expect\((.*)\.calls\.mostRecent\(\)(\.args\[.*\])?\)\.toEqual\((.*)\);/g,
      'expect($1).toHaveBeenCalledWith($2);'
    );
    result = result.replace(
      /expect\((.*)\.calls\.count\(\)\)\.toBe\((.*)\);/g,
      'expect($1).toHaveBeenCalledTimes($2);'
    );
    result = result.replace(
      /expect\((.*)\.calls\.count\(\)\)\.toEqual\((.*)\);/g,
      'expect($1).toHaveBeenCalledTimes($2);'
    );
    result = result.replace(/\.calls\.first\(\).args/g, '.mock.calls[0].args');
    result = result.replace(/\.calls\.reset\(\)/g, '.mockClear()');
    result = result.replace(/and.callFake/g, 'mockImplementation');
    result = result.replace(/\.and.callThrough\(\)/g, '');
    result = result.replace(/innerText/g, 'textContent');

    result = result.replace(/jasmine\.createSpy\(.*?\)/g, 'jest.fn()');
    result = result.replace('jasmine.any(', 'expect.any(');
    result = result.replace('jasmine.anything(', 'expect.anything(');
    result = result.replace(/jasmine\.objectContaining/g, 'expect.objectContaining');

    if (result.includes('createSpyObj')) {
      result = result.replace(/jasmine\.createSpyObj/g, 'createSpyObj');
      result = result.replace(/createSpyObject/g, 'createSpyObj');
      result = result.replace(/: SpyObject<(.*)>/g, ': any');
      result = result.replace(/createSpyObj<(.*)>/g, 'createSpyObj');
      result = result.replace(/<Spy>/g, '');

      result = "import { createSpyObj } from '@test-utilities/create-spy';\r\n" + result;
    }

    result = result.replace('import SpyObj = SpyObj;', '');
    result = result.replace('import Spy = jasmine.Spy;', '');
    result = result.replace('import createSpyObj = createSpyObj;', '');
    result = result.replace(/ Spy;/g, ' jest.SpyInstance;');
    result = result.replace(/jasmine\.Spy;/g, 'jest.SpyInstance;');

    if (result.includes('withArgs')) {
      result = result.replace(
        /(.*)\.withArgs\((.*)\)\.mockReturnValue\((.*)\)/g,
        `$1.mockImplementation(flag => {
        switch (flag) {
          case $2:
            return $3;
        }
      })`
      );
    }

    result = result.replace(/jest\.jest/g, 'jest');

    let newFile = filename.replace('.spec.ts', '.test.ts');
    fs.writeFile(newFile, result, 'utf8', function(err) {
      if (err) return console.log(err);
      console.log('Successfully wrote ' + newFile);
      if (newFile != filename) {
        fs.unlinkSync(filename);
      }
    });
  });
}