istanbul ignore with grunt for typescript

gistfile1.txt

 grunt.loadNpmTasks('grunt-text-replace');

  grunt.initConfig({
    'replace': {
      default: {
        src: ['lib/**/*.js'],
        overwrite: true,
        replacements: [
          {
            from: 'var __extends = (this && this.__extends)',
            to: '/* istanbul ignore next: TypeScript extends */\nvar __extends = (this && this.__extends)'
          },
          {
            from: 'var __assign = (this && this.__assign)',
            to: '/* istanbul ignore next: TypeScript assign */\nvar __assign = (this && this.__assign)'
          },
          {
            from: 'var __decorate = (this && this.__decorate)',
            to: '/* istanbul ignore next: TypeScript decorate */\nvar __decorate = (this && this.__decorate)'
          },
          {
            from: 'var __metadata = (this && this.__metadata)',
            to: '/* istanbul ignore next: TypeScript metadata */\nvar __metadata = (this && this.__metadata)'
          },
          {
            from: 'var __param = (this && this.__param)',
            to: '/* istanbul ignore next: TypeScript param */\nvar __param = (this && this.__param)'
          },
          {
            from: 'var __awaiter = (this && this.__awaiter)',
            to: '/* istanbul ignore next: TypeScript metadata */\nvar __awaiter = (this && this.__awaiter)'
          }
        ]
      }
    },